AD AD9510

1.2 GHz Clock Distribution IC, PLL Core,
Dividers, Delay Adjust, Eight Outputs
AD9510
FEATURES
VS
GND
RSET
CPRSET VCP
DISTRIBUTION
REF
REFIN
R DIVIDER
REFINB
N DIVIDER
FUNCTION
AD9510
PHASE
FREQUENCY
DETECTOR
SYNCB,
RESETB
PDB
PLL
SETTINGS
CP
STATUS
CLK2
CLK2B
PROGRAMMABLE
DIVIDERS AND
PHASE ADJUST
LVPECL
OUT0
/1, /2, /3... /31, /32
OUT0B
LVPECL
OUT1
/1, /2, /3... /31, /32
OUT1B
LVPECL
OUT2
/1, /2, /3... /31, /32
OUT2B
SCLK
SDIO
LVPECL
SERIAL
CONTROL
PORT
OUT3
/1, /2, /3... /31, /32
OUT3B
CSB
Low jitter, low phase noise clock distribution
Clocking high speed ADCs, DACs, DDSs, DDCs, DUCs, MxFEs
High performance wireless transceivers
High performance instrumentation
Broadband infrastructure
CHARGE
PUMP
CLK1
CLK1B
SDO
APPLICATIONS
PLL
REF
LVDS/CMOS
OUT4
/1, /2, /3... /31, /32
OUT4B
LVDS/CMOS
/1, /2, /3... /31, /32
OUT5
ΔT
OUT5B
LVDS/CMOS
/1, /2, /3... /31, /32
OUT6
ΔT
OUT6B
LVDS/CMOS
/1, /2, /3... /31, /32
OUT7
OUT7B
05046-001
Low phase noise phase-locked loop core
Reference input frequencies to 250 MHz
Programmable dual-modulus prescaler
Programmable charge pump (CP) current
Separate CP supply (VCPS) extends tuning range
Two 1.6 GHz, differential clock inputs
8 programmable dividers, 1 to 32, all integers
Phase select for output-to-output coarse delay adjust
4 independent 1.2 GHz LVPECL outputs
Additive output jitter 225 fs rms
4 independent 800 MHz/250 MHz LVDS/CMOS clock outputs
Additive output jitter 275 fs rms
Fine delay adjust on 2 LVDS/CMOS outputs
Serial control port
Space-saving 64-lead LFCSP
FUNCTIONAL BLOCK DIAGRAM
Figure 1.
GENERAL DESCRIPTION
The AD9510 provides a multi-output clock distribution
function along with an on-chip PLL core. The design emphasizes
low jitter and phase noise to maximize data converter
performance. Other applications with demanding phase noise
and jitter requirements also benefit from this part.
The PLL section consists of a programmable reference divider
(R); a low noise phase frequency detector (PFD); a precision
charge pump (CP); and a programmable feedback divider (N).
By connecting an external VCXO or VCO to the CLK2/CLK2B
pins, frequencies up to 1.6 GHz may be synchronized to the
input reference.
There are eight independent clock outputs. Four outputs are
LVPECL (1.2 GHz), and four are selectable as either LVDS
(800 MHz) or CMOS (250 MHz) levels.
Each output has a programmable divider that may be bypassed
or set to divide by any integer up to 32. The phase of one clock
output relative to another clock output may be varied by means
of a divider phase select function that serves as a coarse timing
adjustment. Two of the LVDS/CMOS outputs feature
programmable delay elements with full-scale ranges up to 10 ns
of delay. This fine tuning delay block has 5-bit resolution, giving
32 possible delays from which to choose for each full-scale
setting.
The AD9510 is ideally suited for data converter clocking
applications where maximum converter performance is
achieved by encode signals with subpicosecond jitter.
The AD9510 is available in a 64-lead LFCSP and can be
operated from a single 3.3 V supply. An external VCO, which
requires an extended voltage range, can be accommodated
by connecting the charge pump supply (VCP) to 5.5 V. The
temperature range is −40°C to +85°C.
Rev. A
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2005 Analog Devices, Inc. All rights reserved.
AD9510
TABLE OF CONTENTS
Specifications..................................................................................... 4
A and B Counters................................................................... 30
PLL Characteristics ...................................................................... 4
Determining Values for P, A, B, and R ................................ 30
Clock Inputs .................................................................................. 5
Phase Frequency Detector (PFD) and Charge Pump ....... 31
Clock Outputs ............................................................................... 6
Antibacklash Pulse................................................................. 31
Timing Characteristics ................................................................ 7
STATUS Pin ............................................................................ 31
Clock Output Phase Noise .......................................................... 9
PLL Digital Lock Detect........................................................ 31
Clock Output Additive Time Jitter........................................... 12
PLL Analog Lock Detect ....................................................... 32
PLL and Distribution Phase Noise and Spurious................... 14
Loss of Reference.................................................................... 32
Serial Control Port ..................................................................... 15
FUNCTION Pin ......................................................................... 33
FUNCTION Pin ......................................................................... 15
RESETB: 58h<6:5> = 00b (Default)..................................... 33
STATUS Pin ................................................................................ 16
SYNCB: 58h<6:5> = 01b ....................................................... 33
Power............................................................................................ 16
PDB: 58h<6:5> = 11b ............................................................ 33
Timing Diagrams............................................................................ 17
Distribution Section................................................................... 33
Absolute Maximum Ratings.......................................................... 18
CLK1 and CLK2 Clock Inputs.................................................. 33
Thermal Characteristics ............................................................ 18
Dividers........................................................................................ 33
ESD Caution................................................................................ 18
Setting the Divide Ratio ........................................................ 34
Pin Configuration and Function Descriptions........................... 19
Setting the Duty Cycle........................................................... 34
Terminology .................................................................................... 21
Divider Phase Offset.............................................................. 38
Typical Performance Characteristics ........................................... 22
Delay Block ................................................................................. 39
Typical Modes of Operation.......................................................... 26
Calculating the Delay ............................................................ 39
PLL with External VCXO/VCO Followed by Clock
Distribution................................................................................. 26
Outputs ........................................................................................ 39
Power-Down Modes .................................................................. 40
Clock Distribution Only............................................................ 26
Chip Power-Down or Sleep Mode—PDB........................... 40
PLL with External VCO and Band-Pass Filter Followed by
Clock Distribution...................................................................... 27
PLL Power-Down................................................................... 40
Functional Description .................................................................. 29
Distribution Power-Down .................................................... 40
Overall.......................................................................................... 29
Individual Clock Output Power-Down............................... 40
PLL Section ................................................................................. 29
Individual Circuit Block Power-Down................................ 40
PLL Reference Input—REFIN .............................................. 29
Reset Modes ................................................................................ 41
VCO/VCXO Clock Input—CLK2........................................ 29
Power-On Reset—Start-Up Conditions
when VS is Applied ................................................................ 41
PLL Reference Divider—R .................................................... 29
VCO/VCXO Feedback Divider—N (P, A, B) ..................... 29
Rev. A | Page 2 of 60
Asynchronous Reset via the FUNCTION Pin ................... 41
Soft Reset via the Serial Port................................................. 41
AD9510
Single-Chip Synchronization.....................................................41
Register Map Description ..........................................................49
SYNCB—Hardware SYNC ....................................................41
Power Supply ...................................................................................56
Soft SYNC—Register 58h<2> ...............................................41
Power Management ....................................................................56
Multichip Synchronization ........................................................41
Applications .....................................................................................57
Serial Control Port ..........................................................................42
Using the AD9510 Outputs for ADC Clock Applications ....57
Serial Control Port Pin Descriptions........................................42
CMOS Clock Distribution.........................................................57
General Operation of Serial Control Port ...............................42
LVPECL Clock Distribution......................................................58
Framing a Communication Cycle with CSB .......................42
LVDS Clock Distribution...........................................................58
Communication Cycle—Instruction Plus Data..................42
Power and Grounding Considerations and Power Supply
Rejection.......................................................................................58
Write .........................................................................................42
Read ..........................................................................................43
The Instruction Word (16 Bits).................................................43
Outline Dimensions........................................................................59
Ordering Guide ...........................................................................59
MSB/LSB First Transfers ............................................................43
Register Map and Description.......................................................46
Summary Table............................................................................46
REVISION HISTORY
5/05—Rev. 0 to Rev. A
Changes to Features ..........................................................................1
Changes to Table 1 and Table 2 .......................................................5
Changes to Table 4 ............................................................................8
Changes to Table 5 ............................................................................9
Changes to Table 6 ..........................................................................14
Changes to Table 8 and Table 9 .....................................................15
Changes to Table 11 ........................................................................16
Changes to Table 13 ........................................................................20
Changes to Figure 7 and Figure 10 ...............................................22
Changes to Figure 19 to Figure 23 ................................................24
Changes to Figure 30 and Figure 31 .............................................26
Changes to Figure 32 ......................................................................27
Changes to Figure 33 ......................................................................28
Changes to VCO/VCXO Clock Input—CLK2 Section ..............29
Changes to A and B Counters Section .........................................30
Changes to PLL Digital Lock Detect Section ..............................31
Changes to PLL Analog Lock Detect Section..............................32
Changes to Loss of Reference Section ..........................................32
Changes to FUNCTION Pin Section ...........................................33
Changes to RESETB: 58h<6:5> = 00b (Default) Section ...........33
Changes to SYNCB: 58h<6:5> = 01b Section..............................33
Changes to CLK1 and CLK2 Clock Inputs Section....................33
Changes to Calculating the Delay Section...................................38
Changes to Soft Reset via the Serial Port Section .......................41
Changes to Multichip Synchronization Section..........................41
Changes to Serial Control Port Section .......................................42
Changes to Serial Control Port Pin Descriptions Section .........42
Changes to General Operation of Serial
Control Port Section .......................................................................42
Added Framing a Communication Cycle with CSB Section ....42
Added Communication Cycle—Instruction Plus
Data Section.....................................................................................42
Changes to Write Section...............................................................42
Changes to Read Section................................................................42
Changes to The Instruction Word (16 Bits) Section ..................43
Changes to Table 20 ........................................................................43
Changes to MSB/LSB First Transfers Section..............................43
Changes to Table 21 ........................................................................44
Added Figure 52; Renumbered Sequentially...............................45
Changes to Table 23 ........................................................................46
Changes to Table 24 ........................................................................49
Changes to Using the AD9510 Outputs for ADC Clock
Applications .....................................................................................57
4/05—Revision 0: Initial Version
Rev. A | Page 3 of 60
AD9510
SPECIFICATIONS
Typical (typ) is given for VS = 3.3 V ± 5%; VS ≤ VCPS ≤ 5.5 V, TA = 25°C, RSET = 4.12 kΩ, CPRSET = 5.1 kΩ, unless otherwise noted.
Minimum (min) and maximum (max) values are given over full VS and TA (−40°C to +85°C) variation.
PLL CHARACTERISTICS
Table 1.
Parameter
REFERENCE INPUTS (REFIN)
Input Frequency
Input Sensitivity
Self-Bias Voltage, REFIN
Self-Bias Voltage, REFINB
Input Resistance, REFIN
Input Resistance, REFINB
Input Capacitance
PHASE/FREQUENCY DETECTOR (PFD)
PFD Input Frequency
PFD Input Frequency
PFD Input Frequency
Antibacklash Pulse Width
Antibacklash Pulse Width
Antibacklash Pulse Width
CHARGE PUMP (CP)
ICP Sink/Source
High Value
Low Value
Absolute Accuracy
CPRSET Range
ICP Three-State Leakage
Sink-and-Source Current Matching
ICP vs. VCP
ICP vs. Temperature
RF CHARACTERISTICS (CLK2) 2
Input Frequency
Input Sensitivity
Input Common-Mode Voltage, VCM
Input Common-Mode Range, VCMR
Input Sensitivity, Single-Ended
Input Resistance
Input Capacitance
CLK2 VS. REFIN DELAY
PRESCALER (PART OF N DIVIDER)
Prescaler Input Frequency
P = 2 DM (2/3)
P = 4 DM (4/5)
P = 8 DM (8/9)
P = 16 DM (16/17)
P = 32 DM (32/33)
CLK2 Input Frequency for PLL
Min
Typ
0
1.45
1.40
4.0
4.5
150
1.60
1.50
4.9
5.4
2
Max
Unit
250
MHz
mV p-p
V
V
kΩ
kΩ
pF
1.75
1.60
5.8
6.3
100
100
45
1.5
1.3
1.3
2.9
6.0
MHz
MHz
MHz
ns
ns
ns
4.8
0.60
2.5
2.7/10
1
2
1.5
2
mA
mA
%
kΩ
nA
%
%
%
150
1.6
1.6
GHz
1.7
1.8
mV p-p
V
V
mV p-p
150
4.0
4.8
2
500
5.6
600
1000
1600
1600
1600
300
kΩ
pF
ps
MHz
MHz
MHz
MHz
MHz
MHz
Rev. A | Page 4 of 60
Test Conditions/Comments
Self-bias voltage of REFIN 1.
Self-bias voltage of REFINB1.
Self-biased1.
Self-biased1.
Antibacklash pulse width 0Dh<1:0> = 00b.
Antibacklash pulse width 0Dh<1:0> = 01b.
Antibacklash pulse width 0Dh<1:0> = 10b.
0Dh<1:0> = 00b (this is the default setting).
0Dh<1:0> = 01b.
0Dh<1:0> = 10b.
Programmable.
With CPRSET = 5.1 kΩ.
VCP = VCPs/2.
0.5 < VCP < VCPs − 0.5 V.
0.5 < VCP < VCPs − 0.5 V.
VCP = VCPs/2 V.
Frequencies > 1200 MHz (LVPECL) or 800 MHz
(LVDS) require a minimum divide-by-2 (see the
Distribution Section).
Self-biased; enables ac coupling.
With 200 mV p-p signal applied.
CLK2 ac-coupled; CLK2B capacitively
bypassed to RF ground.
Self-biased.
Difference at PFD.
See the VCO/VCXO Feedback Divider—N (P, A, B)
section.
A, B counter input frequency.
AD9510
Parameter
NOISE CHARACTERISTICS
In-Band Noise of the Charge Pump/
Phase Frequency Detector (In-Band
Means Within the LBW of the PLL)
Min
Typ
Max
Unit
Test Conditions/Comments
The synthesizer phase noise floor is
estimated by measuring the in-band
phase noise at the output of the VCO and
subtracting 20logN (where N is the
N divider value).
@ 50 kHz PFD Frequency
@ 2 MHz PFD Frequency
@ 10 MHz PFD Frequency
@ 50 MHz PFD Frequency
PLL Figure of Merit
−172
−156
−149
−142
−218 +
10 × log (fPFD)
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
3.5
7.5
3.5
ns
ns
ns
7
15
11
ns
ns
ns
PLL DIGITAL LOCK DETECT WINDOW 4
Required to Lock
(Coincidence of Edges)
Low Range (ABP 1.3 ns, 2.9 ns)
High Range (ABP 1.3 ns, 2.9 ns)
High Range (ABP 6 ns)
To Unlock After Lock (Hysteresis)4
Low Range (ABP 1.3 ns, 2.9 ns)
High Range (ABP 1.3 ns, 2.9 ns)
High Range (ABP 6 ns)
Approximation of the PFD/CP phase noise
floor (in the flat region) inside the PLL loop
bandwidth. When running closed loop this
phase noise is gained up by 20 × log(N) 3.
Signal available at STATUS pin
when selected by 08h<5:2>.
Selected by Register ODh.
<5> = 1b.
<5> = 0b.
<5> = 0b.
Selected by Register ODh.
<5> = 1b.
<5> = 0b.
<5> = 0b.
1
REFIN and REFINB self-bias points are offset slightly to avoid chatter on an open input condition.
CLK2 is electrically identical to CLK1; the distribution-only input can be used as differential or single-ended input (see the Clock Inputs section).
3
Example: −218 + 10 × log(fPFD) + 20 × log(N) should give the values for the in-band noise at the VCO output.
4
For reliable operation of the digital lock detect, the period of the PFD frequency must be greater than the unlock-after-lock time.
2
CLOCK INPUTS
Table 2.
Parameter
CLOCK INPUTS (CLK1, CLK2) 1
Input Frequency
Input Sensitivity
Min
Typ
0
Unit
1.6
GHz
mV p-p
150 2
Input Level
Input Common-Mode Voltage, VCM
Input Common-Mode Range, VCMR
Input Sensitivity, Single-Ended
Input Resistance
Input Capacitance
Max
1.5
1.3
4.0
1.6
150
4.8
2
23
V p-p
1.7
1.8
V
V
mV p-p
kΩ
pF
5.6
1
Test Conditions/Comments
Jitter performance can be improved with higher slew
rates (greater swing).
Larger swings turn on the protection diodes and can
degrade jitter performance.
Self-biased; enables ac coupling.
With 200 mV p-p signal applied; dc coupled.
CLK2 ac-coupled; CLK2B ac-bypassed to RF ground.
Self-biased.
CLK1 and CLK2 are electrically identical; each can be used as either differential or single-ended input.
With a 50 Ω termination, this is −12.5 dBm.
3
With a 50 Ω termination, this is +10 dBm.
2
Rev. A | Page 5 of 60
AD9510
CLOCK OUTPUTS
Table 3.
Parameter
LVPECL CLOCK OUTPUTS
OUT0, OUT1, OUT2, OUT3; Differential
Output Frequency
Output High Voltage (VOH)
Output Low Voltage (VOL)
Output Differential Voltage (VOD)
LVDS CLOCK OUTPUTS
OUT4, OUT5, OUT6, OUT7; Differential
Output Frequency
Differential Output Voltage (VOD)
Delta VOD
Output Offset Voltage (VOS)
Delta VOS
Short-Circuit Current (ISA, ISB)
CMOS CLOCK OUTPUTS
OUT4, OUT5, OUT6, OUT7
Output Frequency
Output Voltage High (VOH)
Output Voltage Low (VOL)
Min
Typ
Max
Unit
VS − 1.22
VS − 2.10
660
VS − 0.98
VS − 1.80
810
1200
VS − 0.93
VS − 1.67
965
MHz
V
V
mV
250
360
1.125
1.23
14
800
450
25
1.375
25
24
250
VS − 0.1
0.1
Rev. A | Page 6 of 60
MHz
mV
mV
V
mV
mA
MHz
V
V
Test Conditions/Comments
Termination = 50 Ω to VS − 2 V
Output level 3Ch (3Dh) (3Eh) (3Fh)<3:2> = 10b
See Figure 21
Termination = 100 Ω differential; default
Output level 40h (41h) (42h) (43h)<2:1> = 01b
3.5 mA termination current
See Figure 22
Output shorted to GND
Single-ended measurements;
B outputs: inverted, termination open
With 5 pF load each output; see Figure 23
@ 1 mA load
@ 1 mA load
AD9510
TIMING CHARACTERISTICS
Table 4.
Parameter
LVPECL
Output Rise Time, tRP
Output Fall Time, tFP
PROPAGATION DELAY, tPECL, CLK-TO-LVPECL OUT 1
Divide = Bypass
Divide = 2 − 32
Variation with Temperature
OUTPUT SKEW, LVPECL OUTPUTS
OUT1 to OUT0 on Same Part, tSKP 2
OUT2 to OUT3 on Same Part, tSKP2
All LVPECL OUTs on Same Part, tSKP2
All LVPECL OUTs Across Multiple Parts, tSKP_AB 3
Same LVPECL OUT Across Multiple Parts, tSKP_AB3
LVDS
Output Rise Time, tRL
Output Fall Time, tFL
PROPAGATION DELAY, tLVDS, CLK-TO-LVDS OUT1
OUT4, OUT5, OUT6, OUT7
Divide = Bypass
Divide = 2 − 32
Variation with Temperature
OUTPUT SKEW, LVDS OUTPUTS
OUT4 to OUT7 on Same Part, tSKV2
OUT5 to OUT6 on Same Part, tSKV2
All LVDS OUTs on Same Part, tSKV2
All LVDS OUTs Across Multiple Parts, tSKV_AB3
Same LVDS OUT Across Multiple Parts, tSKV_AB3
CMOS
Output Rise Time, tRC
Output Fall Time, tFC
PROPAGATION DELAY, tCMOS, CLK-TO-CMOS OUT1
Divide = Bypass
Divide = 2 − 32
Variation with Temperature
OUTPUT SKEW, CMOS OUTPUTS
All CMOS OUTs on Same Part, tSKC2
All CMOS OUTs Across Multiple Parts, tSKC_AB3
Same CMOS OUT Across Multiple Parts, tSKC_AB3
LVPECL-TO-LVDS OUT
Output Skew, tSKP_V
LVPECL-TO-CMOS OUT
Output Skew, tSKP_C
LVDS-TO-CMOS OUT
Output Skew, tSKV_C
Min
Typ
Max
Unit
130
130
180
180
ps
ps
335
375
490
545
0.5
635
695
ps
ps
ps/°C
−5
15
90
+30
45
130
+85
80
180
275
130
ps
ps
ps
ps
ps
200
210
350
350
ps
ps
1.33
1.38
0.9
1.59
1.64
ns
ns
ps/°C
+270
+155
+270
450
325
ps
ps
ps
ps
ps
681
646
865
992
ps
ps
1.02
1.07
1.39
1.44
1
1.71
1.76
ns
ns
ps/°C
−140
+145
+300
650
500
ps
ps
ps
0.74
0.92
1.14
ns
0.88
1.14
1.43
ns
158
353
506
ps
0.99
1.04
Test Conditions/Comments
Termination = 50 Ω to VS − 2 V
Output level 3Ch (3Dh) (3Eh) (3Fh)<3:2> = 10b
20% to 80%, measured differentially
80% to 20%, measured differentially
Termination = 100 Ω differential
Output level 40h (41h) (42h) (43h)<2:1> = 01b
3.5 mA termination current
20% to 80%, measured differentially
80% to 20%, measured differentially
Delay off on OUT5 and OUT6
Delay off on OUT5 and OUT6
−85
−175
−175
B outputs are inverted; termination = open
20% to 80%; CLOAD = 3 pF
80% to 20%; CLOAD = 3 pF
Delay off on OUT5 and OUT6
Delay off on OUT5 and OUT6
Rev. A | Page 7 of 60
Everything the same; different logic type
LVPECL to LVDS on same part
Everything the same; different logic type
LVPECL to CMOS on same part
Everything the same; different logic type
LVDS to CMOS on same part
AD9510
Parameter
DELAY ADJUST 4
Shortest Delay Range 5
Zero Scale
Full Scale
Linearity, DNL
Linearity, INL
Longest Delay Range5
Zero Scale
Full Scale
Linearity, DNL
Linearity, INL
Delay Variation with Temperature
Long Delay Range, 10 ns 6
Zero Scale
Full Scale
Short Delay Range, 1 ns6
Zero Scale
Full Scale
Min
Typ
Max
Unit
0.05
0.72
0.36
1.12
0.5
0.8
0.68
1.51
ns
ns
LSB
LSB
0.20
9.0
0.57
10.2
0.3
0.6
0.95
11.6
ns
ns
LSB
LSB
0.35
−0.14
ps/°C
ps/°C
0.51
0.67
ps/°C
ps/°C
1
Test Conditions/Comments
OUT5 (OUT6); LVDS and CMOS
35h (39h) <5:1> 11111b
36h (3Ah) <5:1> 00000b
36h (3Ah) <5:1> 11111b
35h (39h) <5:1> 00000b
36h (3Ah) <5:1> 00000b
36h (3Ah) <5:1> 11111b
The measurements are for CLK1. For CLK2, add approximately 25 ps.
This is the difference between any two similar delay paths within a single device operating at the same voltage and temperature.
3
This is the difference between any two similar delay paths across multiple devices operating at the same voltage and temperature.
4
The maximum delay that can be used is a little less than one-half the period of the clock. A longer delay disables the output.
5
Incremental delay; does not include propagation delay.
6
All delays between zero scale and full scale can be estimated by linear interpolation.
2
Rev. A | Page 8 of 60
AD9510
CLOCK OUTPUT PHASE NOISE
Table 5.
Parameter
CLK1-TO-LVPECL ADDITIVE PHASE NOISE
CLK1 = 622.08 MHz, OUT = 622.08 MHz
Divide Ratio = 1
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
>1 MHz Offset
CLK1 = 622.08 MHz, OUT = 155.52 MHz
Divide Ratio = 4
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
>1 MHz Offset
CLK1 = 622.08 MHz, OUT = 38.88 MHz
Divide Ratio = 16
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
>1 MHz Offset
CLK1 = 491.52 MHz, OUT = 61.44 MHz
Divide Ratio = 8
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
> 1 MHz Offset
CLK1 = 491.52 MHz, OUT = 245.76 MHz
Divide Ratio = 2
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
>1 MHz Offset
CLK1 = 245.76 MHz, OUT = 61.44 MHz
Divide Ratio = 4
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
>1 MHz Offset
Min
Typ
Max
Unit
−125
−132
−140
−148
−153
−154
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−128
−140
−148
−155
−161
−161
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−135
−145
−158
−165
−165
−166
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−131
−142
−153
−160
−165
−165
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−125
−132
−140
−151
−157
−158
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−138
−144
−154
−163
−164
−165
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
Rev. A | Page 9 of 60
Test Conditions/Comments
Distribution Section only; does not
include PLL or external VCO/VCXO
Input slew rate > 1 V/ns
AD9510
Parameter
CLK1-TO-LVDS ADDITIVE PHASE NOISE
CLK1 = 622.08 MHz, OUT= 622.08 MHz
Divide Ratio = 1
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 622.08 MHz, OUT = 155.52 MHz
Divide Ratio = 4
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 491.52 MHz, OUT = 245.76 MHz
Divide Ratio = 2
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 491.52 MHz, OUT = 122.88 MHz
Divide Ratio = 4
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 245.76 MHz, OUT = 245.76 MHz
Divide Ratio = 1
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 245.76 MHz, OUT = 122.88 MHz
Divide Ratio = 2
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
Min
Typ
Max
Unit
−100
−110
−118
−129
−135
−140
−148
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−112
−122
−132
−142
−148
−152
−155
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−108
−118
−128
−138
−145
−148
−154
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−118
−129
−136
−147
−153
−156
−158
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−108
−118
−128
−138
−145
−148
−155
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−118
−127
−137
−147
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
Rev. A | Page 10 of 60
Test Conditions/Comments
Distribution Section only; does not
include PLL or external VCO/VCXO
AD9510
Parameter
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1-TO-CMOS ADDITIVE PHASE NOISE
CLK1 = 245.76 MHz, OUT = 245.76 MHz
Divide Ratio = 1
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 245.76 MHz, OUT = 61.44 MHz
Divide Ratio = 4
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 78.6432 MHz, OUT = 78.6432 MHz
Divide Ratio = 1
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
@ 1 MHz Offset
>10 MHz Offset
CLK1 = 78.6432 MHz, OUT = 39.3216 MHz
Divide Ratio = 2
@ 10 Hz Offset
@ 100 Hz Offset
@ 1 kHz Offset
@ 10 kHz Offset
@ 100 kHz Offset
>1 MHz Offset
Min
Typ
−154
−156
−158
Max
Unit
dBc/Hz
dBc/Hz
dBc/Hz
Test Conditions/Comments
Distribution Section only; does not
include PLL or external VCO/VCXO
−110
−121
−130
−140
−145
−149
−156
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−122
−132
−143
−152
−158
−160
−162
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−122
−132
−140
−150
−155
−158
−160
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
−128
−136
−146
−155
−161
−162
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
Rev. A | Page 11 of 60
AD9510
CLOCK OUTPUT ADDITIVE TIME JITTER
Table 6.
Parameter
LVPECL OUTPUT ADDITIVE TIME JITTER
CLK1 = 622.08 MHz
Any LVPECL (OUT0 to OUT3) = 622.08 MHz
Divide Ratio = 1
CLK1 = 622.08 MHz
Any LVPECL (OUT0 to OUT3) = 155.52 MHz
Divide Ratio = 4
CLK1 = 400 MHz
Any LVPECL (OUT0 to OUT3) = 100 MHz
Divide Ratio = 4
CLK1 = 400 MHz
Any LVPECL (OUT0 to OUT3) = 100 MHz
Divide Ratio = 4
All Other LVPECL = 100 MHz
All LVDS (OUT4 to OUT7) = 100 MHz
CLK1 = 400 MHz
Any LVPECL (OUT0 to OUT3) = 100 MHz
Divide Ratio = 4
All Other LVPECL = 50 MHz
All LVDS (OUT4 to OUT7) = 50 MHz
CLK1 = 400 MHz
Any LVPECL (OUT0 to OUT3) = 100 MHz
Divide Ratio = 4
All Other LVPECL = 50 MHz
All CMOS (OUT4 to OUT7) = 50 MHz (B Outputs Off)
CLK1 = 400 MHz
Min
Typ
Max
40
fs rms
Test Conditions/Comments
Distribution Section only;
does not include PLL or external VCO/VCXO
BW = 12 kHz − 20 MHz (OC-12)
55
fs rms
BW = 12 kHz − 20 MHz (OC-3)
215
fs rms
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
215
fs rms
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
222
225
225
Unit
fs rms
fs rms
fs rms
Any LVPECL (OUT0 to OUT3) = 100 MHz
Divide Ratio = 4
All Other LVPECL = 50 MHz
All CMOS (OUT4 to OUT7) = 50 MHz (B Outputs On)
LVDS OUTPUT ADDITIVE TIME JITTER
CLK1 = 400 MHz
264
fs rms
LVDS (OUT4, OUT7) = 100 MHz
Divide Ratio = 4
CLK1 = 400 MHz
319
fs rms
LVDS (OUT5, OUT6) = 100 MHz
Divide Ratio = 4
Rev. A | Page 12 of 60
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Distribution Section only;
does not include PLL or external VCO/VCXO
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
AD9510
Parameter
CLK1 = 400 MHz
LVDS (OUT4, OUT7) = 100 MHz
Divide Ratio = 4
All Other LVDS = 50 MHz
All LVPECL = 50 MHz
CLK1 = 400 MHz
LVDS (OUT5, OUT6) = 100 MHz
Divide Ratio = 4
All Other LVDS = 50 MHz
All LVPECL = 50 MHz
CLK1 = 400 MHz
LVDS (OUT4, OUT7) = 100 MHz
Divide Ratio = 4
All Other CMOS = 50 MHz (B Outputs Off)
All LVPECL = 50 MHz
CLK1 = 400 MHz
LVDS (OUT5, OUT6) = 100 MHz
Divide Ratio = 4
All Other CMOS = 50 MHz (B Outputs Off)
All LVPECL = 50 MHz
CLK1 = 400 MHz
LVDS (OUT4, OUT7) = 100 MHz
Divide Ratio = 4
All Other CMOS = 50 MHz (B Outputs On)
All LVPECL = 50 MHz
CLK1 = 400 MHz
Min
Typ
395
Max
395
367
367
548
548
Unit
fs rms
fs rms
fs rms
fs rms
fs rms
fs rms
LVDS (OUT5, OUT6) = 100 MHz
Divide Ratio = 4
All Other CMOS = 50 MHz (B Outputs On)
All LVPECL = 50 MHz
CMOS OUTPUT ADDITIVE TIME JITTER
CLK1 = 400 MHz
275
fs rms
Any CMOS (OUT4 to OUT7) = 100 MHz (B Output On)
Divide Ratio = 4
CLK1 = 400 MHz
400
fs rms
Any CMOS (OUT4 to OUT7) = 100 MHz (B Output On)
Divide Ratio = 4
All LVPECL = 50 MHz
All Other LVDS = 50 MHz
CLK1 = 400 MHz
374
Any CMOS (OUT4 to OUT7) = 100 MHz (B Output On)
Divide Ratio = 4
All LVPECL = 50 MHz
All Other CMOS = 50 MHz (B Output Off)
fs rms
Test Conditions/Comments
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Distribution Section only;
does not include PLL or external VCO/VCXO
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Rev. A | Page 13 of 60
AD9510
Parameter
CLK1 = 400 MHz
Min
Typ
555
Any CMOS (OUT4 to OUT7) = 100 MHz (B Output On)
Divide Ratio = 4
All LVPECL = 50 MHz
All Other CMOS = 50 MHz (B Output On)
DELAY BLOCK ADDITIVE TIME JITTER 1
100 MHz Output
Delay FS = 1 ns (1600 μA, 1C) Fine Adj. 00000
Delay FS = 1 ns (1600 μA, 1C) Fine Adj. 11111
Delay FS = 2 ns (800 μA, 1C) Fine Adj. 00000
Delay FS = 2 ns (800 μA, 1C) Fine Adj. 11111
Delay FS = 3 ns (800 μA, 4C) Fine Adj. 00000
Delay FS = 3 ns (800 μA, 4C) Fine Adj. 11111
Delay FS = 4 ns (400 μA, 4C) Fine Adj. 00000
Delay FS = 4 ns (400 μA, 4C) Fine Adj. 11111
Delay FS = 5 ns (200 μA, 1C) Fine Adj. 00000
Delay FS = 5 ns (200 μA, 1C) Fine Adj. 11111
Delay FS = 11 ns (200 μA, 4C) Fine Adj. 00000
Delay FS = 11 ns (200 μA, 4C) Fine Adj. 00100
1
Max
Unit
fs rms
Test Conditions/Comments
Calculated from SNR of ADC method;
FC = 100 MHz with AIN = 170 MHz
Interferer(s)
Interferer(s)
Incremental additive jitter1
0.61
0.73
0.71
1.2
0.86
1.8
1.2
2.1
1.3
2.7
2.0
2.8
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
ps
This value is incremental. That is, it is in addition to the jitter of the LVDS or CMOS output without the delay. To estimate the total jitter, the LVDS or CMOS output jitter
should be added to this value using the root sum of the squares (RSS) method.
PLL AND DISTRIBUTION PHASE NOISE AND SPURIOUS
Table 7.
Parameter
PHASE NOISE AND SPURIOUS
Min
Typ
Max
Unit
VCXO = 245.76 MHz,
FPFD = 1.2288 MHz; R = 25, N = 200
245.76 MHz Output
Phase Noise @100 kHz Offset
Spurious
<−145
<−97
dBc/Hz
dBc
61.44 MHz Output
Phase Noise @100 kHz Offset
Spurious
<−155
<−97
dBc/Hz
dBc
Rev. A | Page 14 of 60
Test Conditions/Comments
Depends on VCO/VCXO selection. Measured at LVPECL
clock outputs; ABP = 6 ns; ICP = 5 mA; Ref = 30.72 MHz.
VCXO is Toyocom TCO-2112 245.76.
Divide by 1.
Dominated by VCXO phase noise.
First and second harmonics of FPFD.. Below measurement
floor.
Divide by 4.
Dominated by VCXO phase noise.
First and second harmonics of FPFD.. Below measurement
floor.
AD9510
SERIAL CONTROL PORT
Table 8.
Parameter
CSB, SCLK (INPUTS)
Min
Input Logic 1 Voltage
Input Logic 0 Voltage
Input Logic 1 Current
Input Logic 0 Current
Input Capacitance
SDIO (WHEN INPUT)
Input Logic 1 Voltage
Input Logic 0 Voltage
Input Logic 1 Current
Input Logic 0 Current
Input Capacitance
SDIO, SDO (OUTPUTS)
Output Logic 1 Voltage
Output Logic 0 Voltage
TIMING
Clock Rate (SCLK, 1/tSCLK)
Pulse Width High, tPWH
Pulse Width Low, tPWL
SDIO to SCLK Setup, tDS
SCLK to SDIO Hold, tDH
SCLK to Valid SDIO and SDO, tDV
CSB to SCLK Setup and Hold, tS, tH
CSB Minimum Pulse Width High, tPWH
2.0
Typ
Max
0.8
110
1
2
2.0
0.8
10
10
2
2.7
0.4
25
16
16
2
1
6
2
3
Unit
Test Conditions/Comments
CSB and SCLK have 30 kΩ
internal pull-down resistors
V
V
μA
μA
pF
V
V
nA
nA
pF
V
V
MHz
ns
ns
ns
ns
ns
ns
ns
FUNCTION PIN
Table 9.
Parameter
INPUT CHARACTERISTICS
Min
Logic 1 Voltage
Logic 0 Voltage
Logic 1 Current
Logic 0 Current
Capacitance
RESET TIMING
Pulse Width Low
SYNC TIMING
Pulse Width Low
2.0
Typ
Max
0.8
110
1
2
Unit
Test Conditions/Comments
The FUNCTION pin has a 30 kΩ internal pull-down resistor.
This pin should normally be held high. Do not leave NC.
V
V
μA
μA
pF
50
ns
1.5
High speed clock cycles
Rev. A | Page 15 of 60
High speed clock is CLK1 or CLK2,
whichever is being used for distribution
AD9510
STATUS PIN
Table 10.
Parameter
OUTPUT CHARACTERISTICS
Min
Output Voltage High (VOH)
Output Voltage Low (VOL)
MAXIMUM TOGGLE RATE
2.7
Typ
Max
Unit
0.4
V
V
MHz
100
ANALOG LOCK DETECT
Capacitance
pF
3
Test Conditions/Comments
When selected as a digital output (CMOS); there are other modes
in which the STATUS pin is not CMOS digital output. See Figure 37.
Applies when PLL mux is set to any divider or counter output,
or PFD up/down pulse. Also applies in analog lock detect mode.
Usually debug mode only. Beware that spurs may couple
to output when this pin is toggling.
On-chip capacitance; used to calculate RC time
constant for analog lock detect readback. Use a pull-up resistor.
POWER
Table 11.
Parameter
POWER-UP DEFAULT MODE POWER DISSIPATION
Min
Typ
550
Max
600
Unit
mW
Power Dissipation
1.1
W
Power Dissipation
1.3
W
Power Dissipation
1.5
W
Full Sleep Power-Down
35
60
mW
Power-Down (PDB)
60
80
mW
POWER DELTA
CLK1, CLK2 Power-Down
Divider, DIV 2 − 32 to Bypass
LVPECL Output Power-Down (PD2, PD3)
10
23
50
15
27
65
25
33
75
mW
mW
mW
LVDS Output Power-Down
CMOS Output Power-Down (Static)
CMOS Output Power-Down (Dynamic)
80
56
115
92
70
150
110
85
190
mW
mW
mW
CMOS Output Power-Down (Dynamic)
125
165
210
mW
Delay Block Bypass
20
24
60
mW
PLL Section Power-Down
5
15
40
mW
Rev. A | Page 16 of 60
Test Conditions/Comments
Power-up default state; does not include power
dissipated in output load resistors. No clock.
All outputs on. Four LVPECL outputs @ 800 MHz,
4 LVDS out @ 800 MHz. Does not include power
dissipated in external resistors.
All outputs on. Four LVPECL outputs @ 800 MHz,
4 CMOS [email protected] 62 MHz (5 pF load). Does not include
power dissipated in external resistors.
All outputs on. Four LVPECL outputs @ 800 MHz,
4 CMOS out @ 125 MHz (5 pF load). Does not include
power dissipated in external resistors.
Maximum sleep is entered by setting 0Ah<1:0> = 01b
and 58h<4> = 1b. This powers off the PLL BG and the
distribution BG references. Does not include power
dissipated in terminations.
Set the FUNCTION pin for PDB operation by setting
58h<6:5> = 11b. Pull PDB low. Does not include
power dissipated in terminations.
For each divider.
For each output. Does not include dissipation
in termination (PD2 only).
For each output.
For each output. Static (no clock).
For each CMOS output, single-ended.
Clocking at 62 MHz with 5 pF load.
For each CMOS output, single-ended.
Clocking at 125 MHz with 5 pF load.
Versus delay block operation at 1 ns fs
with maximum delay; output clocking at 25 MHz.
AD9510
TIMING DIAGRAMS
DIFFERENTIAL
tCLK1
CLK1
80%
LVDS
tRL
tFL
05046-065
20%
tPECL
05046-002
tLVDS
tCMOS
Figure 4. LVDS Timing, Differential
Figure 2. CLK1/CLK1B to Clock Output Timing, DIV = 1 Mode
DIFFERENTIAL
SINGLE-ENDED
80%
80%
LVPECL
CMOS
3pF LOAD
tRP
tFP
tRC
Figure 3. LVPECL Timing, Differential
tFC
Figure 5. CMOS Timing, Single-Ended, 3 pF Load
Rev. A | Page 17 of 60
05046-066
20%
05046-064
20%
AD9510
ABSOLUTE MAXIMUM RATINGS
Table 12.
Parameter or Pin
VS
VCP
VCP
REFIN, REFINB
RSET
CPRSET
CLK1, CLK1B, CLK2, CLK2B
CLK1
CLK2
SCLK, SDIO, SDO, CSB
OUT0, OUT1, OUT2, OUT3
OUT4, OUT5, OUT6, OUT7
FUNCTION
STATUS
Junction Temperature 1
Storage Temperature
Lead Temperature (10 sec)
With
Respect
to
GND
GND
VS
GND
GND
GND
GND
CLK1B
CLK2B
GND
GND
GND
GND
GND
Min
−0.3
−0.3
−0.3
−0.3
−0.3
−0.3
−0.3
−1.2
−1.2
−0.3
−0.3
−0.3
−0.3
−0.3
−65
Max
+3.6
+5.8
+5.8
VS + 0.3
VS + 0.3
VS + 0.3
VS + 0.3
+1.2
+1.2
VS + 0.3
VS + 0.3
VS + 0.3
VS + 0.3
VS + 0.3
150
+150
300
Unit
V
V
V
V
V
V
V
V
V
V
V
V
V
V
°C
°C
°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
sections of this specification is not implied. Exposure to
absolute maximum ratings for extended periods may affect
device reliability.
THERMAL CHARACTERISTICS 2
Thermal Resistance
64-Lead LFCSP
θJA = 24°C/W
1
2
See Thermal Characteristics for θJA.
Thermal impedance measurements were taken on a 4-layer board in still air
in accordance with EIA/JESD51-7.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. A | Page 18 of 60
AD9510
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
VS
CPRSET
GND
RSET
VS
VS
OUT0
OUT0B
VS
GND
OUT1
OUT1B
VS
VS
GND
GND
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
PIN 1
INDICATOR
AD9510
TOP VIEW
(Not to Scale)
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
VS
OUT4
OUT4B
VS
VS
OUT5
OUT5B
VS
VS
OUT6
OUT6B
VS
VS
OUT2
OUT2B
VS
05046-003
STATUS
SCLK
SDIO
SDO
CSB
GND
VS
OUT7B
OUT7
VS
GND
OUT3B
OUT3
VS
VS
GND
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
REFIN
REFINB
GND
VS
VCP
CP
GND
GND
VS
CLK2
CLK2B
GND
VS
CLK1
CLK1B
FUNCTION
Figure 6. 64-Lead LFCSP Pin Configuration
Note that the exposed paddle on this package is an electrical connection as well as a thermal enhancement. For the device to
function properly, the paddle must be attached to ground, GND.
Rev. A | Page 19 of 60
AD9510
Table 13. Pin Function Descriptions
Pin No.
1
2
3, 7, 8, 12, 22,
27, 32, 49, 50,
55, 62
4, 9, 13, 23, 26,
30, 31, 33, 36,
37, 40, 41, 44,
45, 48, 51, 52,
56, 59, 60, 64
5
Mnemonic
REFIN
REFINB
GND
Description
PLL Reference Input.
Complementary PLL Reference Input.
Ground.
VS
Power Supply (3.3 V) VS.
VCP
6
10
CP
CLK2
11
14
15
16
CLK2B
CLK1
CLK1B
FUNCTION
17
18
19
20
21
24
25
28
29
34
35
38
39
42
43
46
47
53
54
57
58
61
63
STATUS
SCLK
SDIO
SDO
CSB
OUT7B
OUT7
OUT3B
OUT3
OUT2B
OUT2
OUT6B
OUT6
OUT5B
OUT5
OUT4B
OUT4
OUT1B
OUT1
OUT0B
OUT0
RSET
CPRSET
Charge Pump Power Supply VCPS. It should be greater than or equal to VS. VCPS may be set as high as 5.5 V
for VCOs requiring extended tuning range.
Charge Pump Output.
Clock Input Used to Connect External VCO/VCXO to Feedback Divider, N. CLK2 also drives the distribution
section of the chip and may be used as a generic clock input when PLL is not used.
Complementary Clock Input Used in Conjunction with CLK2.
Clock Input that Drives Distribution Section of the Chip.
Complementary Clock Input Used in Conjunction with CLK1.
Multipurpose Input May Be Programmed as a Reset (RESETB), Sync (SYNCB), or Power-Down (PDB) Pin.
This pin is internally pulled down by a 30 kΩ resistor. If this pin is left NC, the part is in reset by default.
To avoid this, connect this pin to VS with a 1 kΩ resistor.
Output Used to Monitor PLL Status and Sync Status.
Serial Data Clock.
Serial Data I/O.
Serial Data Output.
Serial Port Chip Select.
Complementary LVDS/Inverted CMOS Output.
LVDS/CMOS Output.
Complementary LVPECL Output.
LVPECL Output.
Complementary LVPECL Output.
LVPECL Output.
Complementary LVDS/Inverted CMOS Output. OUT6 includes a delay block.
LVDS/CMOS Output. OUT6 includes a delay block.
Complementary LVDS/Inverted CMOS Output. OUT5 includes a delay block.
LVDS/CMOS Output. OUT5 includes a delay block.
Complementary LVDS/Inverted CMOS Output.
LVDS/CMOS Output.
Complementary LVPECL Output.
LVPECL Output.
Complementary LVPECL Output.
LVPECL Output.
Current Set Resistor to Ground. Nominal value = 4.12 kΩ.
Charge Pump Current Set Resistor to Ground. Nominal value = 5.1 kΩ.
Note that the exposed paddle on this package is an electrical connection as well as a thermal enhancement. For the device to
function properly, the paddle must be attached to ground, GND.
Rev. A | Page 20 of 60
AD9510
TERMINOLOGY
Phase Jitter and Phase Noise
An ideal sine wave can be thought of as having a continuous
and even progression of phase with time from 0 to 360 degrees
for each cycle. Actual signals, however, display a certain amount
of variation from ideal phase progression over time. This
phenomenon is called phase jitter. Although many causes can
contribute to phase jitter, one major cause is random noise,
which is characterized statistically as being Gaussian (normal)
in distribution.
This phase jitter leads to a spreading out of the energy of the
sine wave in the frequency domain, producing a continuous
power spectrum. This power spectrum is usually reported as a
series of values whose units are dBc/Hz at a given offset in
frequency from the sine wave (carrier). The value is a ratio
(expressed in dB) of the power contained within a 1 Hz
bandwidth with respect to the power at the carrier frequency.
For each measurement, the offset from the carrier frequency is
also given.
It is meaningful to integrate the total power contained within
some interval of offset frequencies (for example, 10 kHz to
10 MHz). This is called the integrated phase noise over that
frequency offset interval and can be readily related to the time
jitter due to the phase noise within that offset frequency
interval.
Phase noise has a detrimental effect on the performance of
ADCs, DACs, and RF mixers. It lowers the achievable dynamic
range of the converters and mixers, although they are affected
in somewhat different ways.
Time Jitter
Phase noise is a frequency domain phenomenon. In the
time domain, the same effect is exhibited as time jitter. When
observing a sine wave, the time of successive zero crossings is
seen to vary. In a square wave, the time jitter is seen as a
displacement of the edges from their ideal (regular) times of
occurrence. In both cases, the variations in timing from the
ideal are the time jitter. Since these variations are random in
nature, the time jitter is specified in units of seconds root mean
square (rms) or 1 sigma of the Gaussian distribution.
Time jitter that occurs on a sampling clock for a DAC or an
ADC decreases the SNR and dynamic range of the converter.
A sampling clock with the lowest possible jitter provides the
highest performance from a given converter.
Additive Phase Noise
It is the amount of phase noise that is attributable to the device
or subsystem being measured. The phase noise of any external
oscillators or clock sources has been subtracted. This makes it
possible to predict the degree to which the device impacts the
total system phase noise when used in conjunction with the
various oscillators and clock sources, each of which contribute
their own phase noise to the total. In many cases, the phase
noise of one element dominates the system phase noise.
Additive Time Jitter
It is the amount of time jitter that is attributable to the device
or subsystem being measured. The time jitter of any external
oscillators or clock sources has been subtracted. This makes it
possible to predict the degree to which the device will impact
the total system time jitter when used in conjunction with the
various oscillators and clock sources, each of which contribute
their own time jitter to the total. In many cases, the time jitter of
the external oscillators and clock sources dominates the system
time jitter.
Rev. A | Page 21 of 60
AD9510
TYPICAL PERFORMANCE CHARACTERISTICS
1.3
0.8
4 LVPECL + 4 LVDS (DIV ON)
0.7
4 LVPECL + 4 LVDS (DIV BYPASSED)
1.2
POWER (W)
0.5
DEFAULT–3 LVPECL + 2 LVDS (DIV ON)
0.4
4 LVDS ONLY (DIV ON)
0.3
1.1
3 LVPECL + 4 CMOS (DIV ON)
1.0
4 LVPECL ONLY (DIV ON)
0.2
05046-060
0
0
400
OUTPUT FREQUENCY (MHz)
800
Figure 7. Power vs. Frequency—LVPECL, LVDS (PLL Off)
05046-061
0.9
0.1
0.8
0
20
100
120
REFIN (EVAL BOARD)
CLK1 (EVAL BOARD)
3GHz
40
60
80
OUTPUT FREQUENCY (MHz)
Figure 10. Power vs. Frequency—LVPECL, CMOS (PLL Off)
5GHz
5MHz
05046-043
05046-062
3GHz
Figure 11. REFIN Smith Chart (Evaluation Board)
Figure 8. CLK1 Smith Chart (Evaluation Board)
CLK2 (EVAL BOARD)
3GHz
5MHz
05046-044
POWER (W)
0.6
Figure 9. CLK2 Smith Chart (Evaluation Board)
Rev. A | Page 22 of 60
10
0
0
–10
–10
–20
–20
–30
–30
–40
–40
–50
–50
–60
–60
–70
–70
05046-058
10
–80
–90
CENTER 245.75MHz
30kHz/
–80
–90
CENTER 61.44MHz
SPAN 300kHz
30kHz/
SPAN 300kHz
Figure 15. Phase Noise, LVPECL, DIV 4, FVCXO = 245.76 MHz,
FOUT = 61.44 MHz, FPFD = 1.2288 MHz, R = 25, N = 200
Figure 12. Phase Noise, LVPECL, DIV 1, FVCXO = 245.76 MHz,
FOUT = 245.76 MHz, FPFD = 1.2288 MHz, R = 25, N = 200
–20
–30
–40
–50
–60
–70
05046-063
–80
100
CENTER 1.5GHz
250kHz/
–145
–150
–155
–160
–165
–170
0.1
SPAN 2.5MHz
Figure 13. PLL Reference Spurs: VCO 1.5 GHz, FPFD = 1 MHz
4.5
4.5
4.0
4.0
CURRENT FROM CP PIN (mA)
5.0
3.5
PUMP UP
3.0
2.5
2.0
1.5
05046-041
1.0
0.5
0
0
0.5
1.0
1.5
2.0
VOLTAGE ON CP PIN (V)
2.5
100
Figure 16. Phase Noise (Referred to CP Output) vs. PFD Frequency
5.0
PUMP DOWN
1
10
PFD FREQUENCY (MHz)
3.0
3.5
PUMP DOWN
2.5
2.0
1.5
1.0
0.5
0
0
Figure 14. Charge Pump Output Characteristics @ VCPs = 3.3 V
PUMP UP
3.0
05046-042
–90
–140
05046-057
–10
PFD NOISE REFERRED TO PFD INPUT (dBc/Hz)
–135
0
CURRENT FROM CP PIN (mA)
05046-059
AD9510
0.5
1.0
1.5
2.0
2.5
3.0
3.5
VOLTAGE ON CP PIN (V)
4.0
4.5
Figure 17. Charge Pump Output Characteristics @ VCPs = 5.0 V
Rev. A | Page 23 of 60
5.0
AD9510
1.8
DIFFERENTIAL SWING (V p-p)
1.4
1.4
1.4
1.4
VERT 500mV/DIV
05046-056
05046-053
1.4
1.4
100
HORIZ 500ps/DIV
Figure 18. LVPECL Differential Output @ 800 MHz
600
1100
1600
OUTPUT FREQUENCY (MHz)
Figure 21. LVPECL Differential Output Swing vs. Frequency
VERT 100mV/DIV
700
650
600
550
500
100
HORIZ 500ps/DIV
05046-050
05046-054
DIFFERENTIAL SWING (mV p-p)
750
300
500
700
OUTPUT FREQUENCY (MHz)
900
Figure 22. LVDS Differential Output Swing vs. Frequency
Figure 19. LVDS Differential Output @ 800 MHz
3.5
2pF
3.0
OUTPUT (VPK)
2.5
10pF
2.0
1.5
1.0
20pF
VERT 500mV/DIV
0
0
HORIZ 1ns/DIV
Figure 20. CMOS Single-Ended Output @ 250 MHz with 10 pF Load
05046-047
05046-055
0.5
100
200
300
400
OUTPUT FREQUENCY (MHz)
500
600
Figure 23. CMOS Single-Ended Output Swing vs. Frequency and Load
Rev. A | Page 24 of 60
–110
–120
–120
–130
–130
–140
–150
–150
–160
–160
1k
10k
100k
OFFSET (Hz)
1M
–170
10
10M
Figure 24. Additive Phase Noise—LVPECL DIV 1, 245.76 MHz;
Distribution Section Only
–90
–90
–100
–100
–110
–110
L(f) (dBc/Hz)
–80
–120
–130
–150
05046-048
–150
–160
10k
100k
OFFSET (Hz)
1M
–170
10
10M
–110
–120
–120
L(f) (dBc/Hz)
–110
–130
–140
–160
–160
1M
10k
100k
OFFSET (Hz)
1M
10M
–140
–150
10k
100k
OFFSET (Hz)
1k
–130
–150
05046-045
L(f) (dBc/Hz)
–100
1k
100
Figure 28. Additive Phase Noise—LVDS DIV2, 122.88 MHz
Figure 25. Additive Phase Noise—LVDS DIV 1, 245.76 MHz
100
10M
–160
–100
–170
10
1M
–130
–140
1k
10k
100k
OFFSET (Hz)
–120
–140
100
1k
Figure 27. Additive Phase Noise—LVPECL DIV1, 622.08 MHz
–80
–170
10
100
05046-049
100
10M
–170
10
05046-046
–170
10
L(f) (dBc/Hz)
–140
05046-052
L(f) (dBc/Hz)
–110
05046-051
L(f) (dBc/Hz)
AD9510
100
1k
10k
100k
OFFSET (Hz)
1M
Figure 29. Additive Phase Noise—CMOS DIV4, 61.44 MHz
Figure 26. Additive Phase Noise—CMOS DIV 1, 245.76 MHz
Rev. A | Page 25 of 60
10M
AD9510
TYPICAL MODES OF OPERATION
PLL WITH EXTERNAL VCXO/VCO FOLLOWED BY
CLOCK DISTRIBUTION
CLOCK DISTRIBUTION ONLY
This is the most common operational mode for the AD9510.
An external oscillator (shown as VCO/VCXO) is phase locked
to a reference input frequency applied to REFIN. The loop filter
is usually a passive design. A VCO or a VCXO can be used. The
CLK2 input is connected internally to the feedback divider, N.
The CLK2 input provides the feedback path for the PLL. If the
VCO/VCXO frequency exceeds maximum frequency of the
output(s) being used, an appropriate divide ratio must be set in
the corresponding divider(s) in the Distribution Section. Some
power can be saved by shutting off unused functions, as well as
by powering down any unused clock channels (see the Register
Map and Description section).
It is possible to use only the distribution section whenever the
PLL section is not needed. Some power can be saved by
shutting the PLL block off, as well as by powering down any
unused clock channels (see the Register Map and Description
section).
In distribution mode, both the CLK1 and CLK2 inputs are
available for distribution to outputs via a low jitter multiplexer
(mux).
VREF
AD9510
REFIN
R
PFD
N
FUNCTION
VREF
CLOCK
INPUT 1
PLL
REF
CHARGE
PUMP
STATUS
CLK1
CLK2
CLOCK
INPUT 2
LVPECL
REFIN
R
PFD
N
FUNCTION
CHARGE
PUMP
DIVIDE
LOOP
FILTER
LVPECL
DIVIDE
STATUS
CLK1
CLK2
LVPECL
VCXO,
VCO
DIVIDE
LVPECL
LVPECL
DIVIDE
SERIAL
PORT
LVPECL
DIVIDE
LVDS/CMOS
DIVIDE
LVDS/CMOS
DIVIDE
LVPECL
DIVIDE
ΔT
DIVIDE
ΔT
DIVIDE
LVDS/CMOS
LVDS/CMOS
CLOCK
OUTPUTS
DIVIDE
LVDS/CMOS
DIVIDE
LVDS/CMOS
DIVIDE
ΔT
DIVIDE
ΔT
Figure 31. Clock Distribution Mode
LVDS/CMOS
LVDS/CMOS
DIVIDE
Figure 30. PLL and Clock Distribution Mode
Rev. A | Page 26 of 60
05046-011
SERIAL
PORT
CLOCK
OUTPUTS
DIVIDE
LVPECL
05046-010
REFERENCE
INPUT
AD9510
PLL
REF
AD9510
PLL WITH EXTERNAL VCO AND BAND-PASS
FILTER FOLLOWED BY CLOCK DISTRIBUTION
An external band-pass filter may be used to try to improve the
phase noise and spurious characteristics of the PLL output. This
option is most appropriate to optimize cost by choosing a less
expensive VCO combined with a moderately priced filter. Note
that the BPF is shown outside of the VCO-to-N divider path,
with the BP filter outputs routed to CLK1. Some power can be
saved by shutting off unused functions, as well as by powering
down any unused clock channels (see the Register Map and
Description section).
VREF
REFIN
R
CHARGE
PUMP
PFD
N
FUNCTION
LOOP
FILTER
STATUS
CLK1
CLK2
VCO
LVPECL
BPF
DIVIDE
LVPECL
DIVIDE
LVPECL
DIVIDE
LVPECL
SERIAL
PORT
DIVIDE
LVDS/CMOS
CLOCK
OUTPUTS
DIVIDE
LVDS/CMOS
DIVIDE
ΔT
LVDS/CMOS
DIVIDE
ΔT
LVDS/CMOS
DIVIDE
Figure 32. AD9510 with VCO and BPF Filter
Rev. A | Page 27 of 60
05046-012
REFERENCE
INPUT
PLL
REF
AD9510
AD9510
VS
GND
RSET
DISTRIBUTION
REF
REFIN
R DIVIDER
REFINB
N DIVIDER
FUNCTION
AD9510
PHASE
FREQUENCY
DETECTOR
SYNCB,
RESETB,
PDB
PLL
REF
CHARGE
PUMP
PLL
SETTINGS
CLK1
1.6GHz
CP
STATUS
CLK2
CLK1B
CLK2B
PROGRAMMABLE
DIVIDERS AND
PHASE ADJUST
1.6GHz
LVPECL
OUT0
/1, /2, /3... /31, /32
OUT0B
LVPECL
OUT1
/1, /2, /3... /31, /32
OUT1B
1.2GHz
LVPECL
LVPECL
OUT2
/1, /2, /3... /31, /32
OUT2B
SCLK
SDIO
SDO
LVPECL
SERIAL
CONTROL
PORT
OUT3
/1, /2, /3... /31, /32
OUT3B
CSB
LVDS/CMOS
OUT4
/1, /2, /3... /31, /32
OUT4B
LVDS/CMOS
/1, /2, /3... /31, /32
OUT5
ΔT
OUT5B
800MHz
LVDS
OUT6
250MHz
CMOS
LVDS/CMOS
/1, /2, /3... /31, /32
ΔT
OUT6B
LVDS/CMOS
/1, /2, /3... /31, /32
Figure 33. Functional Block Diagram Showing Maximum Frequencies
Rev. A | Page 28 of 60
OUT7
OUT7B
05046-013
250MHz
CPRSET VCP
AD9510
FUNCTIONAL DESCRIPTION
Figure 33 shows a block diagram of the AD9510. The chip
combines a programmable PLL core with a configurable clock
distribution system. A complete PLL requires the addition of a
suitable external VCO (or VCXO) and loop filter. This PLL
can lock to a reference input signal and produce an output that
is related to the input frequency by the ratio defined by the
programmable R and N dividers. The PLL cleans up some jitter
from the external reference signal, depending on the loop
bandwidth and the phase noise performance of the VCO
(VCXO).
capacitor to a quiet ground. Figure 34 shows the equivalent
circuit of REFIN.
VS
10kΩ
12kΩ
REFIN
150Ω
REFINB
10kΩ
10kΩ
150Ω
05046-033
OVERALL
Figure 34. REFIN Equivalent Circuit
VCO/VCXO Clock Input—CLK2
The output from the VCO (VCXO) can be applied to the clock
distribution section of the chip, where it can be divided by any
integer value from 1 to 32. The duty cycle and relative phase of
the outputs can be selected. There are four LVPECL outputs,
(OUT0, OUT1, OUT2, and OUT3) and four outputs that can be
either LVDS or CMOS level outputs (OUT4, OUT5, OUT6, and
OUT7). Two of these outputs (OUT5 and OUT6) can also make
use of a variable delay block.
Alternatively, the clock distribution section can be driven
directly by an external clock signal, and the PLL can be powered
off. Whenever the clock distribution section is used alone, there
is no clock clean-up. The jitter of the input clock signal is
passed along directly to the distribution section and may
dominate at the clock outputs.
The CLK2 differential input is used to connect an external
VCO or VCXO to the PLL. Only the CLK2 input port has a
connection to the PLL N divider. This input can receive up to
1.6 GHz. These inputs are internally self-biased and must be
ac-coupled via capacitors.
Alternatively, CLK2 may be used as an input to the distribution
section. This is accomplished by setting Register 45h<0> = 0b.
The default condition is for CLK1 to feed the distribution
section.
CLOCK INPUT
STAGE
VS
CLK
CLKB
PLL SECTION
2.5kΩ
The AD9510 consists of a PLL section and a distribution
section. If desired, the PLL section can be used separately from
the distribution section.
The AD9510 has a complete PLL core on-chip, requiring only
an external loop filter and VCO/VCXO. This PLL is based on
the ADF4106, a PLL noted for its superb low phase noise
performance. The operation of the AD9510 PLL is nearly
identical to that of the ADF4106, offering an advantage to
those with experience with the ADF series of PLLs. Differences
include the addition of differential inputs at REFIN and CLK2,
a different control register architecture. Also, the prescaler has
been changed to allow N as low as 1. The AD9510 PLL
implements the digital lock detect feature somewhat differently
than the ADF4106 does, offering improved functionality at
higher PFD rates. See the Register Map Description section.
2.5kΩ
5kΩ
05046-016
5kΩ
Figure 35. CLK1, CLK2 Equivalent Input Circuit
PLL Reference Divider—R
The REFIN/REFINB inputs are routed to reference divider, R,
which is a 14-bit counter. R may be programmed to any value
from 1 to 16383 (a value of 0 results in a divide by 1) via its
control register (OBh<5:0>, OCh<7:0>). The output of the R
divider goes to one of the phase/frequency detector inputs. The
maximum allowable frequency into the phase, frequency
detector (PFD) must not be exceeded. This means that the
REFIN frequency divided by R must be less than the maximum
allowable PFD frequency. See Figure 34.
VCO/VCXO Feedback Divider—N (P, A, B)
PLL Reference Input—REFIN
The REFIN/REFINB pins can be driven by either a differential
or a single-ended signal. These pins are internally self-biased so
that they can be ac-coupled via capacitors. It is possible to dccouple to these inputs. If REFIN is driven single-ended, the
unused side (REFINB) should be decoupled via a suitable
The N divider is a combination of a prescaler, P, (3 bits) and
two counters, A (6 bits) and B (13 bits). Although the AD9510’s
PLL is similar to the ADF4106, the AD9510 has a redesigned
prescaler that allows lower values of N. The prescaler has both a
dual modulus (DM) and a fixed divide (FD) mode. The
AD9510 prescaler modes are shown in Table 14.
Rev. A | Page 29 of 60
AD9510
Table 14. PLL Prescaler Modes
Mode
(FD = Fixed Divide
DM = Dual Modulus)
FD
FD
P = 2 DM
P = 4 DM
P = 8 DM
P = 16 DM
P = 32 DM
FD
Value in 0Ah<4:2>
000
001
010
011
100
101
110
111
A and B Counters
Divide By
1
2
P/P + 1 = 2/3
P/P + 1 = 4/5
P/P + 1 = 8/9
P/P + 1 = 16/17
P/P + 1 = 32/33
3
When using the prescaler in FD mode, the A counter is not
used, and the B counter may need to be bypassed. The DM
prescaler modes set some upper limits on the frequency, which
can be applied to CLK2. See Table 15.
Table 15. Frequency Limits of Each Prescaler Mode
Mode (DM = Dual Modulus)
P = 2 DM (2/3)
P = 4 DM (4/5)
P = 8 DM (8/9)
P = 16 DM
P = 32 DM
CLK2
<600 MHz
<1000 MHz
<1600 MHz
<1600 MHz
<1600 MHz
The AD9510 B counter has a bypass mode (B = 1), which is not
available on the ADF4106. The B counter bypass mode is valid
only when using the prescaler in FD mode. The B counter is
bypassed by writing 1 to the B counter bypass bit (0Ah<6> =
1b). The valid range of the B counter is 3 to 8191. The default
after a reset is 0, which is invalid.
Note that the A counter is not used when the prescaler is in
FD mode.
Note also that the A/B counters have their own reset bit,
which is primarily intended for testing. The A and B counters
can also be reset using the R, A, and B counters’ shared reset bit
(09h<0>).
Determining Values for P, A, B, and R
When operating the AD9510 in a dual-modulus mode, the
input reference frequency, FREF, is related to the VCO output
frequency, FVCO.
FVCO = (FREF/R) × (PB + A) = FREF × N/R
When operating the prescaler in fixed divide mode, the A
counter is not used and the equation simplifies to
FVCO = (FREF/R) × (PB) = FREF × N/R
By using combinations of dual modulus and fixed divide
modes, the AD9510 can achieve values of N all the way down
to N = 1. Table 16 shows how a 10 MHz reference input may be
locked to any integer multiple of N. Note that the same value of
N may be derived in different ways, as illustrated by N = 12.
Rev. A | Page 30 of 60
AD9510
Table 16. P, A, B, R—Smallest Values for N
FREF
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
R
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
P
1
2
1
1
1
2
2
2
2
2
2
2
2
2
2
4
4
A
X
X
X
X
X
X
0
1
2
1
X
0
1
X
0
0
1
B
1
1
3
4
5
3
3
3
3
4
5
5
5
6
6
3
3
N
1
2
3
4
5
6
6
7
8
9
10
10
11
12
12
12
13
FVCO
10
20
30
40
50
60
60
70
80
90
100
100
110
120
120
120
130
Phase Frequency Detector (PFD) and Charge Pump
The PFD takes inputs from the R counter and the N counter
(N = BP + A) and produces an output proportional to the
phase and frequency difference between them. Figure 36 is a
simplified schematic. The PFD includes a programmable delay
element that controls the width of the antibacklash pulse. This
pulse ensures that there is no dead zone in the PFD transfer
function and minimizes phase noise and reference spurs. Two
bits in Register 0Dh <1:0> control the width of the pulse.
CHARGE
PUMP
R DIVIDER
D1 Q1
U1
UP
CLR1
PROGRAMMABLE
DELAY
CP
U3
ANTIBACKLASH
PULSE WIDTH
HI
Notes
P = 1, B = 1 (Bypassed)
P = 2, B = 1 (Bypassed)
P = 1, B = 3
P = 1, B = 4
P = 1, B = 5
P = 2, B = 3
P/P + 1 = 2/3, A = 0, B = 3
P/P + 1 = 2/3, A = 1, B = 3
P/P + 1 = 2/3, A = 2, B = 3
P/P + 1 = 2/3, A = 1, B = 4
P = 2, B = 5
P/P + 1 = 2/3, A = 0, B = 5
P/P + 1 = 2/3, A = 1, B = 5
P = 2, B = 6
P/P + 1 = 2/3, A = 0, B = 6
P/P + 1 = 4/5, A = 0, B = 3
P/P + 1 = 4/5, A = 1, B = 3
condition and thereby reduces the potential for certain spurs
that could be impressed on the VCO signal.
STATUS Pin
The output multiplexer on the AD9510 allows access to
various signals and internal points on the chip at the STATUS
pin. Figure 37 shows a block diagram of the STATUS pin
section. The function of the STATUS pin is controlled by
Register 08h<5:2>.
PLL Digital Lock Detect
VP
HI
Mode
FD
FD
FD
FD
FD
FD
DM
DM
DM
DM
FD
DM
DM
FD
DM
DM
DM
CLR2 DOWN
D2 Q2
U2
GND
05046-014
N DIVIDER
Figure 36. PFD Simplified Schematic and Timing (In Lock)
Antibacklash Pulse
The PLL features a programmable antibacklash pulse width
that is set by the value in Register 0Dh<1:0>. The default
antibacklash pulse width is 1.3 ns (0Dh<1:0> = 00b) and
normally should not need to be changed. The antibacklash
pulse eliminates the dead zone around the phase-locked
The STATUS pin can display two types of PLL lock detect:
digital (DLD) and analog (ALD). Whenever digital lock detect
is desired, the STATUS pin provides a CMOS level signal, which
can be active high or active low.
The digital lock detect has one of two time windows, as selected
by Register 0Dh<5>. The default (ODh<5> = 0b) requires the
signal edges on the inputs to the PFD to be coincident within
9.5 ns to set the DLD true, which then must separate by at least
15 ns to give DLD = false.
The other setting (ODh<5> = 1) makes these coincidence times
3.5 ns for DLD = true and 7 ns for DLD = false.
The DLD may be disabled by writing 1 to Register 0Dh<6>.
If the signal at REFIN goes away while DLD is true, the DLD
will not necessarily indicate loss-of-lock. See the Loss of
Reference section for more information.
Rev. A | Page 31 of 60
AD9510
OFF (LOW) (DEFAULT)
DIGITAL LOCK DETECT (ACTIVE HIGH)
N DIVIDER OUTPUT
DIGITAL LOCK DETECT (ACTIVE LOW)
R DIVIDER OUTPUT
ANALOG LOCK DETECT (N-CHANNEL OPEN DRAIN)
A COUNTER OUTPUT
PRESCALER OUTPUT (NCLK)
PFD UP PULSE
PFD DOWN PULSE
LOSS OF REFERENCE (ACTIVE HIGH)
TRI-STATE
ANALOG LOCK DETECT (P-CHANNEL OPEN DRAIN)
LOSS OF REFERENCE OR LOCK DETECT (ACTIVE HIGH)
LOSS OF REFERENCE OR LOCK DETECT (ACTIVE LOW)
LOSS OF REFERENCE (ACTIVE LOW)
SYNC
DETECT
CONTROL FOR ANALOG
LOCK DETECT MODE
VS
STATUS
PIN
GND
05046-015
SYNC DETECT ENABLE
58h <0>
PLL MUX CONTROL
08h <5:2>
Figure 37. STATUS Pin Circuit CLK1 Clock Input
An analog lock detect (ALD) signal may be selected. When
ALD is selected, the signal at the STATUS pin is either an
open-drain P-channel (08h<5:2> = 1100) or an open-drain
N-channel (08h<5:2> = 0101b).
The analog lock detect signal is true (relative to the selected
mode) with brief false pulses. These false pulses get shorter as
the inputs to the PFD are nearer to coincidence and longer as
they are further from coincidence.
To extract a usable analog lock detect signal, an external RC
network is required to provide an analog filter with the
appropriate RC constant to allow for the discrimination of a
lock condition by an external voltage comparator. A 1 kΩ
resistor in parallel with a small capacitance usually fulfills this
requirement. However, some experimentation may be required
to get the desired operation.
The analog lock detect function may introduce some spurious
energy into the clock outputs. It is prudent to limit the use of
the ALD when the best possible jitter/phase noise performance
is required on the clock outputs.
Loss of Reference
The AD9510 PLL can warn of a loss-of-reference signal at
REFIN. The loss-of-reference monitor internally sets a flag
called LREF. Externally, this signal can be observed in several
ways on the STATUS pin, depending on the PLL MUX control
settings in Register 08h<5:2>. The LREF alone can be observed
as an active high signal by setting 08h<5:2> = <1010> or as an
active low signal by setting 08h<5:2> = <1111>.
The loss-of-reference circuit is clocked by the signal from the
VCO, which means that there must be a VCO signal present in
order to detect a loss of reference.
The digital lock detect (DLD) block of the AD9510 requires a
PLL reference signal to be present in order for the digital lock
detect output to be valid. It is possible to have a digital lock
detect indication (DLD = true) that remains true even after a
loss-of-reference signal. For this reason, the digital lock detect
signal alone cannot be relied upon if the reference has been lost.
There is a way to combine the DLD and the LREF into a single
signal at the STATUS pin. Set 08h<5:2> = <1101> to get a signal
that is the logical OR of the loss-of-lock (inverse of DLD) and
the loss-of-reference (LREF) active high. If an active low version
of this same signal is desired, set 08h<5:2> = <1110>.
The reference monitor is enabled only after the DLD signal has
been high for the number of PFD cycles set by the value in
07h<6:5>. This delay is measured in PFD cycles. The delay
ranges from 3 PFD cycles (default) to 24 PFD cycles. When the
reference goes away, LREF goes true and the charge pump goes
into tri-state.
User intervention is required to take the part out of this state.
First, 07h<2> = 0b must be written to disable the loss-ofreference circuit, taking the charge pump out of tri-state and
causing LREF to go false. A second write of 07h<2> = 1 is
required to re-enable the loss-of-reference circuit.
PLL LOOP LOCKS
DLD GOES TRUE
LREF IS FALSE
WRITE 07h<2> = 0
LREF SET FALSE
CHARGE PUMP COMES
OUT OF TRI-STATE
WRITE 07h<2> = 1
LOR ENABLED
n PFD CYCLES WITH
DLD TRUE
(n SET BY 07h<6:5>)
CHARGE PUMP
GOES INTO TRI-STATE.
LREF SET TRUE.
Rev. A | Page 32 of 60
MISSING
REFERENCE
DETECTED
CHECK FOR PRESENCE
OR REFERENCE.
LREF STAYS FALSE IF
REFERENCE IS DETECTED.
Figure 38. Loss of Reference Sequence of Events
05046-034
PLL Analog Lock Detect
AD9510
FUNCTION PIN
DISTRIBUTION SECTION
The FUNCTION pin (16) has three functions that are selected
by the value in Register 58h<6:5>. This pin is internally pulled
down by a 30 kΩ resistor. If this pin is left NC, the part is in
reset by default. To avoid this, connect this pin to VS with a
1 kΩ resistor.
As previously mentioned, the AD9510 is partitioned into two
operational sections: PLL and distribution. The PLL Section
was discussed previously. If desired, the distribution section can
be used separately from the PLL section.
RESETB: 58h<6:5> = 00b (Default)
Either CLK1 or CLK2 may be selected as the input to the
distribution section. The CLK1 input can be connected to drive
the distribution section only. CLK1 is selected as the source for
the distribution section by setting Register 45h<0> = 1. This is
the power-up default state.
In its default mode, the FUNCTION pin acts as RESETB, which
generates an asynchronous reset or hard reset when pulled low.
The resulting reset writes the default values into the serial
control port buffer registers as well as loading them into the
chip control registers. When the RESETB signal goes high
again, a synchronous sync is issued (see the SYNCB: 58h<6:5>
= 01b section) and the AD9510 resumes operation according to
the default values of the registers.
SYNCB: 58h<6:5> = 01b
The FUNCTION pin may be used to cause a synchronization
or alignment of phase among the various clock outputs. The
synchronization applies only to clock outputs that
•
are not powered down
•
the divider is not masked (no sync = 0b)
•
are not bypassed (bypass = 0b)
SYNCB is level and rising edge sensitive. When SYNCB is low,
the set of affected outputs are held in a predetermined state,
defined by each divider’s start high bit. On a rising edge, the
dividers begin after a predefined number of fast clock cycles
(fast clock is the selected clock input, CLK1 or CLK2) as
determined by the values in the divider’s phase offset bits.
The SYNCB application of the FUNCTION pin is always active,
regardless of whether the pin is also assigned to perform reset
or power-down. When the SYNCB function is selected, the
FUNCTION pin does not act as either RESETB or PDB.
PDB: 58h<6:5> = 11b
The FUNCTION pin may also be programmed to work as an
asynchronous full power-down, PDB. Even in this full powerdown mode, there is still some residual VS current because
some on-chip references continue to operate. In PDB mode,
the FUNCTION pin is active low. The chip remains in a powerdown state until PDB is returned to logic high. The chip returns
to the settings programmed prior to the power-down.
CLK1 AND CLK2 CLOCK INPUTS
CLK1 and CLK2 work for inputs up to 1600 MHz. The jitter
performance is improved by a higher input slew rate. The input
level should be between approximately 150 mV p-p to no more
than 2 V p-p. Anything greater may result in turning on the
protection diodes on the input pins, which could degrade the
jitter performance.
See Figure 35 for the CLK1 and CLK2 equivalent input circuit.
These inputs are fully differential and self-biased. The signal
should be ac-coupled using capacitors. If a single-ended input
must be used, this can be accommodated by ac coupling to one
side of the differential input only. The other side of the input
should be bypassed to a quiet ac ground by a capacitor.
The unselected clock input (CLK1 or CLK2) should be powered
down to eliminate any possibility of unwanted crosstalk
between the selected clock input and the unselected clock input.
DIVIDERS
Each of the eight clock outputs of the AD9510 has its own
divider. The divider can be bypassed to get an output at the
same frequency as the input (1×). When a divider is bypassed,
it is powered down to save power.
All integer divide ratios from 1 to 32 may be selected. A divide
ratio of 1 is selected by bypassing the divider.
Each divider can be configured for divide ratio, phase, and duty
cycle. The phase and duty cycle values that can be selected
depend on the divide ratio that is chosen.
See the Chip Power-Down or Sleep Mode—PDB section for
more details on what occurs during a PDB initiated powerdown.
Rev. A | Page 33 of 60
AD9510
Setting the Divide Ratio
Example 2:
The divide ratio is determined by the values written via the SCP
to the registers that control each individual output, OUT0 to
OUT7. These are the even numbered registers beginning at 48h
and going through 56h. Each of these registers is divided into
bits that control the number of clock cycles that the divider
output stays high (high_cycles <3:0>) and the number of clock
cycles that the divider output stays low (low_cycles <7:4>). Each
value is 4 bits and has the range of 0 to 15.
The divide ratio is set by
Set Divide Ratio = 8
high_cycles = 3
low_cycles = 3
Divide Ratio = (3 + 1) + (3 + 1) = 8
Note that a Divide Ratio of 8 may also be obtained by setting:
high_cycles = 2
Divide Ratio = (high_cycles + 1) + (low_cycles + 1)
low_cycles = 4
Example 1:
Divide Ratio = (2 + 1) + (4 + 1) = 8
Set the Divide Ratio = 2
Although the second set of settings produces the same divide
ratio, the resulting duty cycle is not the same.
high_cycles = 0
Setting the Duty Cycle
low_cycles = 0
The duty cycle and the divide ratio are related. Different
divide ratios have different duty cycle options. For example, if
Divide Ratio = 2, the only duty cycle possible is 50%. If the
Divide Ratio = 4, the duty cycle may be 25%, 50%, or 75%.
Divide Ratio = (0 + 1) + (0 + 1) = 2
The duty cycle is set by
Duty Cycle = (high_cycles + 1)/((high_cycles + 1) + (low_cycles + 1))
See Table 17 for the values for the available duty cycles for each
divide ratio.
Table 17. Duty Cycle and Divide Ratio
Divide Ratio
2
3
3
4
4
4
5
5
5
5
6
6
6
6
6
7
7
7
7
Duty Cycle (%)
50
67
33
50
75
25
60
40
80
20
50
67
33
83
17
57
43
71
29
48h to 56h
LO <7:4>
HI<3:0>
0
0
1
1
0
2
1
2
0
3
2
1
3
0
4
2
3
1
4
0
1
0
1
2
0
2
1
3
0
2
3
1
4
0
3
2
4
1
Divide Ratio
7
7
8
8
8
8
8
8
8
9
9
9
9
9
9
9
9
10
10
Rev. A | Page 34 of 60
Duty Cycle (%)
86
14
50
63
38
75
25
88
13
56
44
67
33
78
22
89
11
50
60
48h to 56h
LO <7:4>
HI<3:0>
0
5
3
2
4
1
5
0
6
3
4
2
5
1
6
0
7
4
3
5
0
3
4
2
5
1
6
0
4
3
5
2
6
1
7
0
4
5
AD9510
Divide Ratio
10
10
10
10
10
10
10
11
11
11
11
11
11
11
11
11
11
12
12
12
12
12
12
12
12
12
12
12
13
13
13
13
13
13
13
13
13
13
13
13
14
14
14
14
14
14
14
14
14
14
14
Duty Cycle (%)
40
70
30
80
20
90
10
55
45
64
36
73
27
82
18
91
9
50
58
42
67
33
75
25
83
17
92
8
54
46
62
38
69
31
77
23
85
15
92
8
50
57
43
64
36
71
29
79
21
86
14
48h to 56h
LO <7:4>
HI<3:0>
5
2
6
1
7
0
8
4
5
3
6
2
7
1
8
0
9
5
4
6
3
7
2
8
1
9
0
A
5
6
4
7
3
8
2
9
1
A
0
B
6
5
7
4
8
3
9
2
A
1
B
3
6
2
7
1
8
0
5
4
6
3
7
2
8
1
9
0
5
6
4
7
3
8
2
9
1
A
0
6
5
7
4
8
3
9
2
A
1
B
0
6
7
5
8
4
9
3
A
2
B
1
Divide Ratio
14
14
15
15
15
15
15
15
15
15
15
15
15
15
15
15
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
17
18
18
18
18
Rev. A | Page 35 of 60
Duty Cycle (%)
93
7
53
47
60
40
67
33
73
27
80
20
87
13
93
7
50
56
44
63
38
69
31
75
25
81
19
88
13
94
6
53
47
59
41
65
35
71
29
76
24
82
18
88
12
94
6
50
56
44
61
48h to 56h
LO <7:4>
HI<3:0>
0
C
6
7
5
8
4
9
3
A
2
B
1
C
0
D
7
6
8
5
9
4
A
3
B
2
C
1
D
0
E
7
8
6
9
5
A
4
B
3
C
2
D
1
E
0
F
8
7
9
6
C
0
7
6
8
5
9
4
A
3
B
2
C
1
D
0
7
8
6
9
5
A
4
B
3
C
2
D
1
E
0
8
7
9
6
A
5
B
4
C
3
D
2
E
1
F
0
8
9
7
A
AD9510
Divide Ratio
18
18
18
18
18
18
18
18
18
18
18
19
19
19
19
19
19
19
19
19
19
19
19
19
19
20
20
20
20
20
20
20
20
20
20
20
20
20
21
21
21
21
21
21
21
21
21
21
21
21
22
Duty Cycle (%)
39
67
33
72
28
78
22
83
17
89
11
53
47
58
42
63
37
68
32
74
26
79
21
84
16
50
55
45
60
40
65
35
70
30
75
25
80
20
52
48
57
43
62
38
67
33
71
29
76
24
50
48h to 56h
LO <7:4>
HI<3:0>
A
5
B
4
C
3
D
2
E
1
F
8
9
7
A
6
B
5
C
4
D
3
E
2
F
9
8
A
7
B
6
C
5
D
4
E
3
F
9
A
8
B
7
C
6
D
5
E
4
F
A
6
B
5
C
4
D
3
E
2
F
1
9
8
A
7
B
6
C
5
D
4
E
3
F
2
9
A
8
B
7
C
6
D
5
E
4
F
3
A
9
B
8
C
7
D
6
E
5
F
4
A
Divide Ratio
22
22
22
22
22
22
22
22
22
22
23
23
23
23
23
23
23
23
23
23
24
24
24
24
24
24
24
24
24
25
25
25
25
25
25
25
25
26
26
26
26
26
26
26
27
27
27
27
27
27
28
Rev. A | Page 36 of 60
Duty Cycle (%)
55
45
59
41
64
36
68
32
73
27
52
48
57
43
61
39
65
35
70
30
50
54
46
58
42
63
38
67
33
52
48
56
44
60
40
64
36
50
54
46
58
42
62
38
52
48
56
44
59
41
50
48h to 56h
LO <7:4>
HI<3:0>
9
B
8
C
7
D
6
E
5
F
A
B
9
C
8
D
7
E
6
F
B
A
C
9
D
8
E
7
F
B
C
A
D
9
E
8
F
C
B
D
A
E
9
F
C
D
B
E
A
F
D
B
9
C
8
D
7
E
6
F
5
B
A
C
9
D
8
E
7
F
6
B
C
A
D
9
E
8
F
7
C
B
D
A
E
9
F
8
C
D
B
E
A
F
9
D
C
E
B
F
A
D
AD9510
Divide Ratio
28
28
28
28
29
29
29
29
Duty Cycle (%)
54
46
57
43
52
48
55
45
48h to 56h
LO <7:4>
HI<3:0>
C
E
B
F
D
E
C
F
E
C
F
B
E
D
F
C
Divide Ratio
30
30
30
31
31
32
Rev. A | Page 37 of 60
Duty Cycle (%)
50
53
47
52
48
50
48h to 56h
LO <7:4>
HI<3:0>
E
D
F
E
F
F
E
F
D
F
E
F
AD9510
Divider Phase Offset
The phase of each output may be selected, depending
on the divide ratio chosen. This is selected by writing the
appropriate values to the registers which set the phase and
start high/low bit for each output. These are the odd numbered
registers from 49h to 57h. Each divider has a 4-bit phase offset
<3:0> and a start high or low bit <4>.
Following a sync pulse, the phase offset word determines how
many fast clock (CLK1 or CLK2) cycles to wait before initiating
a clock output edge. The Start H/L bit determines if the divider
output starts low or high. By giving each divider a different
phase offset, output-to-output delays can be set in increments of
the fast clock period, tCLK.
Figure 39 shows four dividers, each set for DIV = 4, 50% duty
cycle. By incrementing the phase offset from 0 to 3, each output
is offset from the initial edge by a multiple of tCLK.
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
CLOCK INPUT
CLK
tCLK
DIVIDER OUTPUTS
DIV = 4, DUTY = 50%
START = 0,
PHASE = 0
START = 0,
PHASE = 1
START = 0,
PHASE = 2
START = 0,
PHASE = 3
tCLK
05046-035
2 × tCLK
3 × tCLK
Figure 39. Phase Offset—All Dividers Set for DIV = 4, Phase Set from 0 to 3
For example:
CLK1 = 491.52 MHz
tCLK1 = 1/491.52 = 2.0345 ns
For DIV = 4
Phase Offset 0 = 0 ns
Phase Offset 1 = 2.0345 ns
Phase Offset 2 = 4.069 ns
Phase Offset 3 = 6.104 ns
The four outputs may also be described as:
OUT1 = 0°
OUT2 = 90°
OUT3 = 180°
Setting the phase offset to Phase = 4 results in the same relative
phase as the first channel, Phase = 0° or 360°.
In general, by combining the 4-bit phase offset and the Start
H/L bit, there are 32 possible phase offset states (see Table 18).
Table 18. Phase Offset—Start H/L Bit
Phase Offset
(Fast Clock
Rising Edges)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
49h to 57h
Phase Offset <3:0>
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Start H/L <4>
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
The resolution of the phase offset is set by the fast clock period
(tCLK) at CLK1 or CLK2. As a result, every divide ratio does not
have 32 unique phase offsets available. For any divide ratio, the
number of unique phase offsets is numerically equal to the
divide ratio (see Table 18):
DIV = 4
Unique Phase Offsets Are Phase = 0, 1, 2, 3
DIV= 7
OUT4 = 270°
Rev. A | Page 38 of 60
AD9510
Unique Phase Offsets Are Phase = 0, 1, 2, 3, 4, 5, 6
DIV = 18
Unique Phase Offsets Are Phase = 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17
Phase offsets may be related to degrees by calculating the phase
step for a particular divide ratio:
Phase Step = 360°/(Divide Ratio) = 360°/DIV
This path adds some jitter greater than that specified for the
nondelay outputs. This means that the delay function should be
used primarily for clocking digital chips, such as FPGA, ASIC,
DUC, and DDC, rather than for data converters. The jitter is
higher for long full scales (~10 ns). This is because the delay
block uses a ramp and trip points to create the variable delay. A
longer ramp means more noise might be introduced.
Calculating the Delay
The following values and equations are used to calculate the
delay of the delay block.
Using some of the same examples,
Value of Ramp Current Control Bits (Register 35h or Register 39h
<2:0>) = Iramp_bits
DIV = 4
Phase Step = 360°/4 = 90°
IRAMP (μA) = 200 × (Iramp_bits + 1)
Unique Phase Offsets in Degrees Are Phase = 0°, 90°,
180°, 270°
DIV = 7
No. of Caps = No. of 0s + 1 in Ramp Control Capacitor
(Register 35h or Register 39h <5:3>), that is, 101 = 1 + 1 = 2; 110
= 2; 100 = 2 + 1 = 3; 001 = 2 + 1 = 3; 111 = 0 + 1 = 1)
Phase Step = 360°/7 = 51.43°
Delay_Range (ns) = 200 × ((No. of Caps + 3)/(IRAMP)) × 1.3286
Unique Phase Offsets in Degrees Are Phase = 0°, 51.43°,
102.86°, 154.29°, 205.71°, 257.15°, 308.57°
⎛ No.of Caps − 1 ⎞
⎟×6
Offset (ns ) = 0.34 + (1600 − I RAMP )× 10 −4 + ⎜⎜
⎟
I RAMP
⎝
⎠
DELAY BLOCK
Delay_Full_Scale (ns) = Delay_Range + Offset
OUT5 and OUT6 (LVDS/CMOS) include an analog delay
element that can be programmed (Register 34h to Register 3Ah)
to give variable time delays (Δt) in the clock signal passing
through that output.
CLOCK INPUT
Fine_Adj = Value of Delay Fine Adjust (Register 36h or
Register 3Ah <5:1>), that is, 11111 = 31
Delay (ns) = Offset + Delay_Range × Fine_adj × (1/31)
OUTPUTS
The AD9510 offers three different output level choices:
LVPECL, LVDS, and CMOS. OUT0 to OUT3 are LVPECL only.
OUT4 to OUT7 can be selected as either LVDS or CMOS. Each
output can be enabled or turned off as needed to save power.
÷N
LVDS
CMOS
FINE DELAY ADJUST
(32 STEPS)
FULL-SCALE: 1ns TO 10ns
OUTPUT
DRIVER
The simplified equivalent circuit of the LVPECL outputs is
shown in Figure 41.
Figure 40. Analog Delay (OUT5 andOUT6)
3.3V
The amount of delay that can be used is determined by the
frequency of the clock being delayed. The amount of delay can
approach one-half cycle of the clock period. For example, for a
10 MHz clock, the delay can extend to the full 10 ns maximum
of which the delay element is capable. However, for a 100 MHz
clock (with 50% duty cycle), the maximum delay is less than
5 ns (or half of the period).
OUT5 and OUT6 allow a full-scale delay in the range 1 ns to
10 ns. The full-scale delay is selected by choosing a combination
of ramp current and the number of capacitors by writing the
appropriate values into Register 35h and Register 39h. There are
32 fine delay settings for each full scale, set by Register 36h and
Register 3Ah.
Rev. A | Page 39 of 60
OUT
OUTB
GND
05046-037
ΔT
05046-036
MUX
∅SELECT
OUT5
OUT6 ONLY
Figure 41. LVPECL Output Simplified Equivalent Circuit
AD9510
Table 19. Register 0Ah: PLL Power-Down
3.5mA
<1>
0
0
1
1
OUT
3.5mA
05046-038
OUTB
POWER-DOWN MODES
Chip Power-Down or Sleep Mode—PDB
The PDB chip power-down turns off most of the functions
and currents in the AD9510. When the PDB mode is enabled, a
chip power-down is activated by taking the FUNCTION pin to
a logic low level. The chip remains in this power-down state
until PDB is brought back to logic high. When woken up, the
AD9510 returns to the settings programmed into its registers
prior to the power-down, unless the registers are changed by
new programming while the PDB mode is active.
The PDB power-down mode shuts down the currents on the
chip, except the bias current necessary to maintain the LVPECL
outputs in a safe shutdown mode. This is needed to protect the
LVPECL output circuitry from damage that could be caused by
certain termination and load configurations when tri-stated.
Because this is not a complete power-down, it can be called
sleep mode.
When the AD9510 is in a PDB power-down or sleep mode, the
chip is in the following state:
•
The PLL is off (asynchronous power-down).
•
All clocks and sync circuits are off.
•
All dividers are off.
•
All LVDS/CMOS outputs are off.
•
All LVPECL outputs are in safe off mode.
•
The serial control port is active, and the chip responds to
commands.
If the AD9510 clock outputs must be synchronized to each
other, a SYNC (see the Single-Chip Synchronization section) is
required upon exiting power-down mode.
The PLL section of the AD9510 can be selectively powered
down. There are three PLL power-down modes, set by the
values in Register 0Ah<1:0>, as shown in Table 19.
Mode
Normal Operation
Asynchronous Power-Down
Normal Operation
Synchronous Power-Down
In asynchronous power-down mode, the device powers down as
soon as the registers are updated.
Figure 42. LVDS Output Simplified Equivalent Circuit
PLL Power-Down
<0>
0
1
0
1
In synchronous power-down mode, the PLL power-down is
gated by the charge pump to prevent unwanted frequency
jumps. The device goes into power-down on the occurrence of
the next charge pump event after the registers are updated.
Distribution Power-Down
The distribution section can be powered down by writing to
Register 58h<3> = 1. This turns off the bias to the distribution
section. If the LVPECL power-down mode is normal operation
<00>, it is possible for a low impedance load on that LVPECL
output to draw significant current during this power-down. If
the LVPECL power-down mode is set to <11>, the LVPECL
output is not protected from reverse bias and can be damaged
under certain termination conditions.
When combined with the PLL power-down, this mode results in
the lowest possible power-down current for the AD9510.
Individual Clock Output Power-Down
Any of the eight clock distribution outputs may be powered
down individually by writing to the appropriate registers via the
SCP. The register map details the individual power-down
settings for each output. The LVDS/CMOS outputs may be
powered down, regardless of their output load configuration.
The LVPECL outputs have multiple power-down modes (see
Register Address 3C, Register Address 3D, Register Address 3E,
and Register Address 3F in Table 24). These give some
flexibility in dealing with various output termination
conditions. When the mode is set to <10>, the LVPECL output
is protected from reverse bias to 2 VBE + 1 V. If the mode is set
to <11>, the LVPECL output is not protected from reverse bias
and can be damaged under certain termination conditions. This
setting also affects the operation when the distribution block is
powered down with Register 58h<3> = 1b (see the Distribution
Power-Down section).
Individual Circuit Block Power-Down
Many of the AD9510 circuit blocks (CLK1, CLK2, REFIN, and
so on) can be powered down individually. This gives flexibility
in configuring the part for power savings whenever certain chip
functions are not needed.
Rev. A | Page 40 of 60
AD9510
RESET MODES
The AD9510 has several ways to force the chip into a reset
condition.
Power-On Reset—Start-Up Conditions when VS is
Applied
A power-on reset (POR) is issued when the VS power supply is
turned on. This initializes the chip to the power-on conditions
that are determined by the default register settings. These are
indicated in the default value column of Table 23.
Asynchronous Reset via the FUNCTION Pin
As mentioned in the FUNCTION Pin section, a hard reset,
RESETB: 58h<6:5> = 00b (Default), restores the chip to the
default settings.
Synchronization of two or more AD9510s requires a fast clock
and a slow clock. The fast clock can be up to 1 GHz and may be
the clock driving the master AD9510 CLK1 input or one of the
outputs of the master. The fast clock acts as the input to the
distribution section of the slave AD9510 and is connected to its
CLK1 input. The PLL may be used on the master, but the slave
PLL is not used.
The slow clock is the clock that is synchronized across the two
chips. This clock must be no faster than one-fourth of the fast
clock, and no greater than 250 MHz. The slow clock is taken
from one of the outputs of the master AD9510 and acts as the
REFIN (or CLK2) input to the slave AD9510. One of the
outputs of the slave must provide this same frequency back to
the CLK2 (or REFIN) input of the slave.
Multichip synchronization is enabled by writing
Register 58h<0> = 1 on the slave AD9510. When this bit is set,
the STATUS pin becomes the output for the SYNC signal. A low
signal indicates an in-sync condition, and a high indicates an
out-of-sync condition.
The serial control port allows a soft reset by writing to
Register 00h<5> = 1b. When this bit is set, the chip executes
a soft reset. This restores the default values to the internal
registers, except for Register 00h itself.
This bit is not self-clearing. The bit must be written to
00h<5> = 0b in order for the operation of the part to continue.
SINGLE-CHIP SYNCHRONIZATION
SYNCB—Hardware SYNC
The AD9510 clocks can be synchronized to each other at any
time. The outputs of the clocks are forced into a known state
with respect to each other and then allowed to continue
clocking from that state in synchronicity. Before a
synchronization is done, the FUNCTION Pin must be set to
act as the SYNCB: 58h<6:5> = 01b input (58h<6:5> = 01b).
Synchronization is done by forcing the FUNCTION pin low,
creating a SYNCB signal and then releasing it.
See the SYNCB: 58h<6:5> = 01b section for a more detailed
description of what happens when the SYNCB: 58h<6:5> = 01b
signal is issued.
Register 58h<1> selects the number of fast clock cycles that are
the maximum separation of the slow clock edges that are
considered synchronized. When 58h<1> = 0 (default), the slow
clock edges must be coincident within 1 to 1.5 high speed clock
cycles. If the coincidence of the slow clock edges is closer than
this amount, the SYNC flag stays low. If the coincidence of the
slow clock edges is greater than this amount, the SYNC flag is
set high. When Register 58h<1> = 1b, the amount of
coincidence required is 0.5 fast clock cycles to 1 fast clock
cycles.
Whenever the SYNC flag is set (high) indicating an out-of-sync
condition, a SYNCB signal applied simultaneously at the
FUNCTION pins of both AD9510s brings the slow clocks into
synchronization.
AD9510
MASTER
FAST CLOCK
<1GHz
OUTN
SLOW CLOCK
<250MHz
OUTM
Soft SYNC—Register 58h<2>
A soft SYNC may be issued by means of a bit in Registers 58h<2>.
This soft SYNC works the same as the SYNCB, except that the
polarity is reversed. A 1 written to this bit forces the clock
outputs into a known state with respect to each other. When a 0
is subsequently written to this bit, the clock outputs continue
clocking from that state in synchronicity.
FUNCTION
(SYNCB)
FSYNC
SYNCB
CLK2
SLAVE
FAST CLOCK
CLK1 <1GHz
MULTICHIP SYNCHRONIZATION
The AD9510 provides a means of synchronizing two or more
AD9510s. This is not an active synchronization; it requires user
monitoring and action. The arrangement of two AD9510s to be
synchronized is shown in Figure 43.
Rev. A | Page 41 of 60
REFIN
AD9510
SLOW
CLOCK
<250MHz
FSYNC
OUTY
SYNC
DETECT
FUNCTION
(SYNCB)
Figure 43. Multichip Synchronization
STATUS
(SYNC)
05046-039
Soft Reset via the Serial Port
AD9510
SERIAL CONTROL PORT
The AD9510 serial control port is a flexible, synchronous, serial
communications port that allows an easy interface with many
industry-standard microcontrollers and microprocessors. The
AD9510 serial control port is compatible with most
synchronous transfer formats, including both the Motorola SPI®
and Intel® SSR® protocols. The serial control port allows
read/write access to all registers that configure the AD9510.
Single or multiple byte transfers are supported, as well as MSB
first or LSB first transfer formats. The AD9510 serial control
port can be configured for a single bidirectional I/O pin (SDIO
only) or for two unidirectional I/O pins (SDIO/SDO).
SERIAL CONTROL PORT PIN DESCRIPTIONS
SCLK (serial clock) is the serial shift clock. This pin is an input.
SCLK is used to synchronize serial control port reads and
writes. Write data bits are registered on the rising edge of this
clock, and read data bits are registered on the falling edge. This
pin is internally pulled down by a 30 kΩ resistor to ground.
SDIO (serial data input/output) is a dual-purpose pin and acts
as either an input only or as both an input/output. The AD9510
defaults to two unidirectional pins for I/O, with SDIO used as
an input, and SDO as an output. Alternatively, SDIO can be
used as a bidirectional I/O pin by writing to the SDO enable
register at 00h<7> = 1b.
SDO (serial data out) is used only in the unidirectional I/O
mode (00h<7> = 0, default) as a separate output pin for reading
back data. The AD9510 defaults to this I/O mode. Bidirectional
I/O mode (using SDIO as both input and output) may be
enabled by writing to the SDO enable register at 00h<7> = 1.
CSB (chip select bar) is an active low control that gates the read
and write cycles. When CSB is high, SDO and SDIO are in a
high impedance state. This pin is internally pulled down by a
30 kΩ resistor to ground. It should not be left NC or tied low.
See the General Operation of Serial Control Port section on the
use of the CSB in a communication cycle.
SDIO (PIN 19)
SDO (PIN 20)
CSB (PIN 21)
AD9510
SERIAL
CONTROL
PORT
05046-017
SCLK (PIN 18)
Figure 44. Serial Control Port
GENERAL OPERATION OF SERIAL CONTROL PORT
Framing a Communication Cycle with CSB
Each communications cycle (a write or a read operation) is
gated by the CSB line. CSB must be brought low to initiate a
communication cycle. CSB must be brought high at the
completion of a communication cycle (see Figure 52). If CSB is
not brought high at the end of each write or read cycle (on a
byte boundary), the last byte is not loaded into the register
buffer.
CSB stall high is supported in modes where three or fewer bytes
of data (plus instruction data) are transferred (W1:W0 must be
set to 00, 01, or 10, see Table 20). In these modes, CSB can
temporarily return high on any byte boundary, allowing time
for the system controller to process the next byte. CSB can go
high on byte boundaries only and can go high during either
part (instruction or data) of the transfer. During this period, the
serial control port state machine enters a wait state until all data
has been sent. If the system controller decides to abort the
transfer before all of the data is sent, the state machine must be
reset by either completing the remaining transfer or by
returning the CSB low for at least one complete SCLK cycle (but
less than eight SCLK cycles). Raising the CSB on a nonbyte
boundary terminates the serial transfer and flushes the buffer.
In the streaming mode (W1:W0 = 11b), any number of data
bytes can be transferred in a continuous stream. The register
address is automatically incremented or decremented (see the
MSB/LSB First Transfers section). CSB must be raised at the
end of the last byte to be transferred, thereby ending the stream
mode.
Communication Cycle—Instruction Plus Data
There are two parts to a communication cycle with the AD9510.
The first writes a 16-bit instruction word into the AD9510,
coincident with the first 16 SCLK rising edges. The instruction
word provides the AD9510 serial control port with information
regarding the data transfer, which is the second part of the
communication cycle. The instruction word defines whether
the upcoming data transfer is a read or a write, the number of
bytes in the data transfer, and the starting register address for
the first byte of the data transfer.
Write
If the instruction word is for a write operation (I15 = 0b), the
second part is the transfer of data into the serial control port
buffer of the AD9510. The length of the transfer (1, 2, 3 bytes,
or streaming mode) is indicated by 2 bits (W1:W0) in the
instruction byte. CSB can be raised after each sequence of 8 bits
to stall the bus (except after the last byte, where it ends the
cycle). When the bus is stalled, the serial transfer resumes when
CSB is lowered. Stalling on nonbyte boundaries resets the serial
control port.
Since data is written into a serial control port buffer area, not
directly into the AD9510’s actual control registers, an additional
operation is needed to transfer the serial control port buffer
contents to the actual control registers of the AD9510, thereby
causing them to take effect. This update command consists of
writing to Register 5Ah<0> = 1b. This update bit is self-clearing
(it is not required to write 0 to it in order to clear it). Since any
number of bytes of data can be changed before issuing an
Rev. A | Page 42 of 60
AD9510
update command, the update simultaneously enables all register
changes since any previous update.
Phase offsets or divider synchronization will not become
effective until a SYNC is issued (see the Single-Chip
Synchronization section).
Read
If the instruction word is for a read operation (I15 = 1b), the
next N × 8 SCLK cycles clock out the data from the address
specified in the instruction word, where N is 1 to 4 as
determined by W1:W0. The readback data is valid on the falling
edge of SCLK.
The default mode of the AD9510 serial control port is
unidirectional mode; therefore, the requested data appears on
the SDO pin. It is possible to set the AD9510 to bidirectional
mode by writing the SDO enable register at 00h<7> = 1b. In
bidirectional mode, the readback data appears on the SDIO pin.
SDO
CSB
SERIAL
CONTROL
PORT
UPDATE
REGISTERS
5Ah <0>
AD9510
CORE
05046-018
SDIO
CONTROL REGISTERS
SCLK
REGISTER BUFFERS
A readback request reads the data that is in the serial control
port buffer area, not the active data in the AD9510’s actual
control registers.
Figure 45. Relationship Between Serial Control Port Register Buffers and
Control Registers of the AD9510
The AD9510 uses Addresses 00h to 5Ah. Although the AD9510
serial control port allows both 8-bit and 16-bit instructions, the
8-bit instruction mode provides access to five address bits (A4
to A0) only, which restricts its use to the address space 00h to
01F. The AD9510 defaults to 16-bit instruction mode on powerup. The 8-bit instruction mode (although defined for this serial
control port) is not useful for the AD9510; therefore, it is not
discussed further in this data sheet.
THE INSTRUCTION WORD (16 BITS)
The MSB of the instruction word is R/W, which indicates
whether the instruction is a read or a write. The next two bits,
W1:W0, indicate the length of the transfer in bytes. The final 13
bits are the address (A12:A0) at which to begin the read or write
operation.
For a write, the instruction word is followed by the number of
bytes of data indicated by Bits W1:W0, which is interpreted
according to Table 20.
Table 20. Byte Transfer Count
W1
0
0
1
1
W0
0
1
0
1
Bytes to Transfer
1
2
3
Streaming mode
A12:A0: These 13 bits select the address within the register map
that is written to or read from during the data transfer portion
of the communications cycle. The AD9510 does not use all of
the 13-bit address space. Only Bits A6:A0 are needed to cover
the range of the 5Ah registers used by the AD9510. Bits A12:A7
must always be 0b. For multibyte transfers, this address is the
starting byte address. In MSB first mode, subsequent bytes
increment the address.
MSB/LSB FIRST TRANSFERS
The AD9510 instruction word and byte data may be MSB first
or LSB first. The default for the AD9510 is MSB first. The LSB
first mode may be set by writing 1b to Register 00h<6>. This
takes effect immediately (since it only affects the operation of
the serial control port) and does not require that an update be
executed. Immediately after the LSB first bit is set, all serial
control port operations are changed to LSB first order.
When MSB first mode is active, the instruction and data bytes
must be written from MSB to LSB. Multibyte data transfers in
MSB first format start with an instruction byte that includes the
register address of the most significant data byte. Subsequent
data bytes must follow in order from high address to low
address. In MSB first mode, the serial control port internal
address generator decrements for each data byte of the
multibyte transfer cycle.
When LSB_First = 1b (LSB first), the instruction and data bytes
must be written from LSB to MSB. Multibyte data transfers in
LSB first format start with an instruction byte that includes the
register address of the least significant data byte followed by
multiple data bytes. The serial control port internal byte address
generator increments for each byte of the multibyte transfer
cycle.
The AD9510 serial control port register address decrements
from the register address just written toward 0000h for
multibyte I/O operations if the MSB first mode is active
(default). If the LSB first mode is active, the serial control port
register address increments from the address just written
toward 1FFFh for multibyte I/O operations.
Unused addresses are not skipped during multibyte I/O
operations; therefore, it is important to avoid multibyte I/O
operations that would include these addresses.
Rev. A | Page 43 of 60
AD9510
Table 21. Serial Control Port, 16-Bit Instruction Word, MSB First
MSB
I15
I14
I13
I12
I11
I10
I9
I8
I7
I6
I5
I4
I3
I2
I1
LSB
I0
R/W
W1
W0
A12 = 0
A11 = 0
A10 = 0
A9 = 0
A8 = 0
A7 = 0
A6
A5
A4
A3
A2
A1
A0
CSB
SCLK DON'T CARE
SDIO DON'T CARE
R/W W1 W0 A12 A11 A10 A9 A8
A7
A6 A5
A4 A3 A2
A1 A0
D7 D6 D5
16-BIT INSTRUCTION HEADER
D4 D3
D2 D1
D0
D7
REGISTER (N) DATA
D6 D5
D4 D3 D2
D1 D0
DON'T CARE
REGISTER (N – 1) DATA
05046-019
DON'T CARE
Figure 46. Serial Control Port Write—MSB First, 16-Bit Instruction, 2 Bytes Data
CSB
SCLK
DON'T CARE
SDIO
DON'T CARE
R/W W1 W0 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
SDO DON'T CARE
REGISTER (N) DATA
REGISTER (N – 1) DATA
REGISTER (N – 2) DATA
REGISTER (N – 3) DATA
DON'T
CARE
05046-020
D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
16-BIT INSTRUCTION HEADER
Figure 47. Serial Control Port Read—MSB First, 16-Bit Instruction, 4 Bytes Data
tDS
tS
tHI
tDH
DON'T CARE
SDIO
DON'T CARE
DON'T CARE
R/W
W1
W0
A12
A11
A10
A9
A8
A7
A6
A5
D4
D3
D2
D1
D0
DON'T CARE
05046-021
SCLK
tH
tCLK
tLO
CSB
Figure 48. Serial Control Port Write−MSB First, 16-Bit Instruction, Timing Measurements
CSB
SCLK
DATA BIT N
05046-022
tDV
SDIO
SDO
DATA BIT N– 1
Figure 49. Timing Diagram for Serial Control Port Register Read
CSB
SCLK DON'T CARE
A0 A1 A2 A3
A4
A5 A6 A7
A8
A9 A10 A11 A12 W0 W1 R/W D0 D1 D2 D3 D4
16-BIT INSTRUCTION HEADER
D5 D6
REGISTER (N) DATA
D7
D0
D1 D2
D6
REGISTER (N + 1) DATA
Figure 50. Serial Control Port Write—LSB First, 16-Bit Instruction, 2 Bytes Data
Rev. A | Page 44 of 60
D3 D4 D5
D7
DON'T CARE
05046-023
SDIO DON'T CARE
DON'T CARE
AD9510
tS
tH
CSB
tCLK
tHI
tLO
tDS
SCLK
SDIO
BI N
05046-040
tDH
BI N + 1
Figure 51. Serial Control Port Timing—Write
Table 22. Serial Control Port Timing
Parameter
tDS
tDH
tCLK
tS
tH
tHI
tLO
Description
Setup time between data and rising edge of SCLK
Hold time between data and rising edge of SCLK
Period of the clock
Setup time between CSB and SCLK
Hold time between CSB and SCLK
Minimum period that SCLK should be in a logic high state
Minimum period that SCLK should be in a logic low state
CSB TOGGLE INDICATES
CYCLE COMPLETE
tPWH
CSB
16 INSTRUCTION BITS + 8 DATA BITS
16 INSTRUCTION BITS + 8 DATA BITS
SCLK
COMMUNICATION CYCLE 1
COMMUNICATION CYCLE 2
TIMING DIAGRAM FOR TWO SUCCESSIVE CUMMUNICATION CYCLES. NOTE THAT CSB MUST
BE TOGGLED HIGH AND THEN LOW AT THE COMPLETION OF A COMMUNICATION CYCLE.
Figure 52. Use of CSB to Define Communications Cycle
Rev. A | Page 45 of 60
05046-067
SDIO
AD9510
REGISTER MAP AND DESCRIPTION
SUMMARY TABLE
Table 23. AD9510 Register Map
Addr
(Hex)
00
Parameter
Serial
Control Port
Configuration
Bit 7 (MSB)
SDO Inactive
(Bidirectional
Mode)
Bit 6
LSB
First
01
02
03
Bit 5
Soft
Reset
Bit 4
Long
Instruction
Bit 3
Bit 2
Bit 1
Not Used
Bit 0
(LSB)
Def.
Value
(Hex)
10
Not Used
Not Used
Not Used
PLL
04
A Counter
05
B Counter
06
B Counter
07
PLL 1
08
PLL 2
09
PLL 3
0A
PLL 4
0B
0C
0D
R Divider
R Divider
PLL 5
OE33
Not Used
6-Bit A Counter <5:0>
Not Used
00
13-Bit B Counter Bits 12:8 (MSB) <4:0>
00
13-Bit B Counter Bits 7:0 (LSB) <7:0>
00
Not Used
Not Used
Not Used
LOR Lock_Del
LOR
<6:5>
Enable
Not Used
CP Mode <1:0>
PFD
PLL Mux Select <5:2>Signal on STATUS
Polarity
pin
Not Used
CP Current <6:4>
Not
Reset R
Reset N Reset All
Used Counter Counter Counters
Not Used
Prescaler P <4:2>
Power-Down <1:0>
B
Not
Bypass
Used
Not Used
14-Bit R Divider Bits 13:8 (MSB) <5:0>
14-Bit R Divider Bits 13:8 (MSB) <7:0>
Not Used
Not Used
Digital
Digital
Antibacklash
Lock
Lock
Pulse Width <1:0>
Det.
Det.
Enable Window
Not Used
34
Delay Bypass 5
35
Delay FullScale 5
Not Used
36
Delay Fine
Adjust 5
Not Used
39
Not Used
5-Bit Fine Delay <5:1>
Not Used
Not Used
Delay Bypass 6
Delay FullScale 6
Ramp Capacitor <5:3>
Not Used
Ramp Capacitor <5:3>
Rev. A | Page 46 of 60
Bypass
Ramp Current <2:0>
Must be
0
Bypass
Ramp Current <2:0>
PLL Starts
in PowerDown
N Divider
(A)
N Divider
(B)
N Divider
(B)
00
00
00
01
00
00
00
FINE DELAY
ADJUST
37
38
Notes
01
00
00
04
01
00
N Divider
(P)
R Divider
R Divider
Fine
Delays
Bypassed
Bypass
Delay
Max.
Delay FullScale
Min. Delay
Value
Bypass
Delay
Max.
Delay FullScale
AD9510
Addr
(Hex)
3A
Parameter
Delay Fine
Adjust 6
Bit 7 (MSB)
Bit 6
Not Used
Bit 5
3B
Bit 1
Not Used
3C
OUTPUTS
LVPECL OUT0
Not Used
3D
LVPECL OUT1
Not Used
3E
LVPECL OUT2
Not Used
3F
LVPECL OUT3
Not Used
40
LVDS_CMOS
OUT 4
Not Used
41
LVDS_CMOS
OUT 5
Not Used
42
LVDS_CMOS
OUT 6
Not Used
43
LVDS_CMOS
OUT 7
Not Used
CMOS
Inverted
Driver On
CMOS
Inverted
Driver On
CMOS
Inverted
Driver On
CMOS
Inverted
Driver On
Not Used
44
45
Bit 4
Bit 3
Bit 2
5-Bit Fine Delay <5:1>
Bit 0
(LSB)
Not
Used
CLK1 AND
CLK2
Clocks Select,
Power-Down
(PD) Options
Not Used
CLKs in
PD
46, 47
REFIN PD
Def.
Value
(Hex)
00
Notes
Min. Delay
Value
04
Power-Down <1:0>
Output Level
<3:2>
Power-Down <1:0>
Output Level
<3:2>
Power-Down <1:0>
Output Level
<3:2>
Power-Down <1:0>
Output Level
<3:2>
Logic
Output Level
Output
Select
<2:1>
Power
0A
OFF
08
ON
08
ON
08
ON
02
LVDS, ON
Logic
Select
Output Level
<2:1>
Output
Power
02
LVDS, ON
Logic
Select
Output Level
<2:1>
Output
Power
03
LVDS, OFF
Logic
Select
Output Level
<2:1>
Output
Power
03
LVDS, OFF
01
Input
Receivers
All Clocks
ON, Select
CLK1
CLK
to
PLL
PD
CLK2
PD
CLK1
PD
Select
CLK IN
Not Used
48
49
DIVIDERS
Divider 0
Divider 0
Bypass
4A
4B
Divider 1
Divider 1
Bypass
4C
4D
Divider 2
Divider 2
Bypass
4E
4F
Divider 3
Divider 3
Bypass
50
51
Divider 4
Divider 4
Bypass
52
53
Divider 5
Divider 5
54
Divider 6
Bypass
Low Cycles <7:4>
Force
No
Sync
Low Cycles <7:4>
Force
No
Sync
Low Cycles <7:4>
Force
No
Sync
Low Cycles <7:4>
Force
No
Sync
Low Cycles <7:4>
Force
No
Sync
Low Cycles <7:4>
Force
No
Sync
Low Cycles <7:4>
Start H/L
High Cycles <3:0>
Phase Offset <3:0>
00
00
Divide by 2
Phase = 0
Start H/L
High Cycles <3:0>
Phase Offset <3:0>
00
00
Divide by 2
Phase = 0
Start H/L
High Cycles <3:0>
Phase Offset <3:0>
11
00
Divide by 4
Phase = 0
Start H/L
High Cycles <3:0>
Phase Offset <3:0>
33
00
Divide by 8
Phase = 0
Start H/L
High Cycles <3:0>
Phase Offset <3:0>
00
00
Divide by 2
Phase = 0
Start H/L
High Cycles <3:0>
Phase Offset <3:0>
11
00
Divide by 4
Phase = 0
High Cycles <3:0>
00
Divide by 2
Rev. A | Page 47 of 60
AD9510
Addr
(Hex)
55
Parameter
Divider 6
56
57
Divider 7
Divider 7
58
FUNCTION
FUNCTION
Pin and Sync
59
5A
Update
Registers
Bit 7 (MSB)
Bypass
Bypass
Not Used
Bit 6
Bit 5
Force
No
Sync
Low Cycles <7:4>
Force
No
Sync
Set FUNCTION Pin
Bit 4
Start H/L
Bit 3
Notes
Phase = 0
00
00
Divide by 2
Phase = 0
Sync
Enable
00
FUNCTION
Pin =
RESETB
Update
Registers
00
SelfClearing
Bit
High Cycles <3:0>
Phase Offset <3:0>
Start H/L
PD Sync
Bit 2
Bit 1
Phase Offset <3:0>
Def.
Value
(Hex)
00
Bit 0
(LSB)
PD All
Ref.
Not Used
Not Used
END
Rev. A | Page 48 of 60
Sync
Reg.
Sync
Select
AD9510
REGISTER MAP DESCRIPTION
Table 24 lists the AD9510 control registers by hexadecimal address. A specific bit or range of bits within a register is indicated by angle
brackets. For example, <3> refers to Bit 3, while <5:2> refers to the range of bits from Bit 5 through Bit 2. Table 24 describes the
functionality of the control registers on a bit-by-bit basis. For a more concise (but less descriptive) table, see Table 23.
Table 24. AD9510 Register Descriptions
Reg.
Addr.
(Hex) Bit(s) Name
Serial Control Port
Configuration
00
<3:0>
00
<4>
Long Instruction
00
<5>
Soft Reset
00
<6>
LSB First
00
<7>
SDO Inactive
(Bidirectional
Mode)
Not Used
01
02
03
<7:0>
<7:0>
<7:0>
04
04
05
05
06
07
07
07
07
<5:0>
<7:6>
<4:0>
<7:5>
<7:0>
<1:0>
<2>
<4:3>
<6:5>
07
08
<7>
<1:0> Charge Pump
Mode
Description
Any changes to this register takes effect immediately. Register 5Ah<0> Update Registers does not
have to be written.
Not Used.
When this bit is set (1), the instruction phase is 16 bits. When clear (0), the instruction phase is 8 bits.
The default, and only, mode for this part is long instruction (Default = 1b).
When this bit is set (1), the chip executes a soft reset, restoring default values to the internal registers,
except for this register, 00h. This bit is not self-clearing. A clear (0) has to be written to it in order
to clear it.
When this bit is set (1), the input and output data is oriented as LSB first. Additionally, register addressing
increments. If this bit is clear (0), data is oriented as MSB first and register addressing decrements.
(Default = 0b, MSB first.)
When set (1), the SDO pin is tri-state and all read data goes to the SDIO pin. When clear (0), the SDO is
active (unidirectional mode). (Default = 0b.)
Not Used
Not Used
Not Used
PLL Settings
A Counter
B Counter MSBs
B Counter LSBs
LOR Enable
LOR Initial Lock
Detect Delay
6-Bit A Counter <5:0>
Not Used
13-Bit B Counter (MSB) <12:8>
Not Used
13-Bit B Counter (LSB) <7:0>
Not Used
1 = Enables the Loss-of-Reference (LOR) Function; (Default = 0b)
Not Used
LOR Initial Lock Detect Delay. Once a lock detect is indicated, this is the number of phase frequency
detector (PFD) cycles that occur prior to turning on the LOR monitor.
<6>
<5>
LOR Initial Lock Detect Delay
0
0
3 PFD Cycles (Default)
0
1
6 PFD Cycles
1
0
12 PFD Cycles
1
1
24 PFD Cycles
Not Used
<1>
0
0
1
1
<0>
0
1
0
1
Rev. A | Page 49 of 60
Charge Pump Mode
Tri-Stated (Default)
Pump-Up
Pump-Down
Normal Operation
AD9510
Reg.
Addr.
(Hex) Bit(s) Name
08
<5:2> PLL Mux Control
08
<6>
08
09
09
09
09
09
<7>
<0>
<1>
<2>
<3>
<6:4>
09
0A
Phase-Frequency
Detector (PFD)
Polarity
Description
<5>
<4>
<3> <2>
MUXOUT—Signal on STATUS Pin
0
0
0
0
Off (Signal Goes Low) (Default)
0
0
0
1
Digital Lock Detect (Active High)
0
0
1
0
N Divider Output
0
0
1
1
Digital Lock Detect (Active Low)
0
1
0
0
R Divider Output
0
1
0
1
Analog Lock Detect (N Channel, Open-Drain)
0
1
1
0
A Counter Output
0
1
1
1
Prescaler Output (NCLK)
1
0
0
0
PFD Up Pulse
1
0
0
1
PFD Down Pulse
1
0
1
0
Loss-of-Reference (Active High)
1
0
1
1
Tri-State
1
1
0
0
Analog Lock Detect (P Channel, Open-Drain)
1
1
0
1
Loss-of-Reference or Loss-of-Lock (Inverse of DLD) (Active High)
1
1
1
0
Loss-of-Reference or Loss-of-Lock (Inverse of DLD) (Active Low)
1
1
1
1
Loss-of-Reference (Active Low)
MUXOUT is the PLL portion of the STATUS output MUX
0 = Negative (Default), 1 = Positive
Not Used
Reset All Counters 0 = Normal (Default), 1 = Reset R, A, and B Counters
N-Counter Reset
0 = Normal (Default), 1 = Reset A and B Counters
R-Counter Reset
0 = Normal (Default), 1 = Reset R Counter
Not Used
Charge Pump (CP)
Current Setting
<6>
<5>
<4>
ICP (mA)
0
0
0
0.60
0
0
1
1.2
0
1
0
1.8
0
1
1
2.4
1
0
0
3.0
1
0
1
3.6
1
1
0
4.2
1
1
1
4.8
Default = 000b
These currents assume: CPRSET = 5.1 kΩ
Actual current can be calculated by: CP_lsb = 3.06/CPRSET
<7>
Not Used
<1:0> PLL Power-Down 01 = Asynchronous Power-Down (Default)
<1>
<0>
Mode
0
0
Normal Operation
0
1
Asynchronous Power-Down
1
0
Normal Operation
1
1
Synchronous Power-Down
Rev. A | Page 50 of 60
AD9510
Reg.
Addr.
(Hex) Bit(s) Name
0A
<4:2> Prescaler Value
(P/P+1)
Description
<4>
<3> <2>
Mode
Prescaler Mode
0
0
0
FD
Divide by 1
0
0
1
FD
Divide by 2
0
1
0
DM
2/3
0
1
1
DM
4/5
1
0
0
DM
8/9
1
0
1
DM
16/17
1
1
0
DM
32/33
1
1
1
FD
Divide by 3
DM = Dual Modulus, FD = Fixed Divide.
Not Used
Only valid when operating the prescaler in fixed divide (FD) mode. When this bit is set, the B counter is
divided by 1. This allows the prescaler setting to determine the divide for the N divider.
0A
0A
<5>
<6>
0A
0B
<7>
Not Used
<5:0> 14-Bit Reference
R Divider (MSB) <13:8>
Counter, MSBs
<7:0> 14-Bit Reference
R Divider (MSB) <7:0>
Counter, R LSBs
<1:0> Antibacklash Pulse
Width
<1>
<0>
Antibacklash Pulse Width (ns)
0
0
1.3 (Default)
0
1
2.9
1
0
6.0
1
1
1.3
<4:2>
Not Used
<5> Digital Lock Detect
Window
<5>
Digital Lock Detect Window (ns)
Digital Lock Detect Loss-of-Lock Threshold (ns)
0C
0D
0D
0D
B Counter Bypass
0 (Default)
9.5
15
1
3.5
7
Digital Lock Detect If the time difference of the rising edges at the inputs to the PFD are less than the lock detect window
Window
time, the digital lock detect flag is set. The flag remains set until the time difference is greater than the
loss-of-lock threshold.
0D
<6> Lock Detect
0 = Normal Lock Detect Operation (Default)
Disable
1 = Disable Lock Detect
0D
<7>
Not Used
Unused
0E-33
Not Used
Fine Delay Adjust
<0> Delay Control
Delay Block Control Bit
34
OUT5
Bypasses Delay Block and Powers It Down (Default = 1b)
(38)
(OUT6)
34
<7:1>
Not Used
(38)
<2:0> Ramp Current
35
OUT5
The slowest ramp (200 μA) sets the longest full scale of approximately 10 ns.
Rev. A | Page 51 of 60
AD9510
Reg.
Addr.
(Hex) Bit(s) Name
(39)
(OUT6)
35
(39)
<5:3> Ramp Capacitor
OUT5
(OUT6)
Description
<2>
<1>
<0>
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
Selects the Number of Capacitors in Ramp Generation Circuit
More Capacitors => Slower Ramp
<5>
0
0
0
0
1
1
1
1
36
(3A)
3C
(3D)
(3E)
(3F)
3C
(3D)
(3E)
<5:1> Delay Fine Adjust
OUT5
(OUT6)
<4>
0
0
1
1
0
0
1
1
<3>
0
1
0
1
0
1
0
1
Ramp Current (μA)
200
400
600
800
1000
1200
1400
1600
Number of Capacitors
4 (Default)
3
3
2
3
2
2
1
Sets Delay Within Full Scale of the Ramp; There are 32 Steps
00000 => Zero Delay (Default)
11111 => Maximum Delay
<1:0> Power-Down
LVPECL
Mode
<1>
<0>
Description
Output
ON
PD1
PD2
0
0
1
0
1
0
Normal Operation
Test Only—Do Not Use
Safe Power-Down
Partial Power-Down; Use If Output Has Load Resistors
ON
OFF
OFF
PD3
1
1
Total Power-Down
Use Only If Output Has No Load Resistors
OFF
OUT0
(OUT1)
(OUT2)
(OUT3)
<3:2> Output Level
LVPECL
OUT0
(OUT1)
Output Single-Ended Voltage Levels for LVPECL Outputs
Rev. A | Page 52 of 60
AD9510
Reg.
Addr.
(Hex) Bit(s) Name
(3F)
(OUT2)
(OUT3)
3C
(3D)
(3E)
(3F)
40
(41)
(42)
(43)
40
(41)
(42)
(43)
40
(41)
(42)
(43)
40
(41)
(42)
(43)
40
(41)
(42)
(43)
44
<3>
0
0
1
1
Not Used
<7:4>
<0>
Description
Power-Down
<2>
0
1
0
1
Output Voltage (mV)
500
340
810 (Default)
660
Power-Down Bit for Both Output and LVDS Driver
0 = LVDS/CMOS on (Default)
1 = LVDS/CMOS Power-Down
LVDS/CMOS
OUT4
(OUT5)
(OUT6)
(OUT7)
<2:1> Output Current
Level
LVDS
OUT4
(OUT5)
(OUT6)
(OUT7)
<2>
<1>
Current (mA)
Termination (Ω)
0
0
1.75
100
0
1
3.5 (Default)
100
1
0
5.25
50
1
1
7
50
<3>
LVDS/CMOS Select 0 = LVDS (Default)
1 = CMOS
OUT4
(OUT5)
(OUT6)
(OUT7)
<4> Inverted CMOS
Effects Output Only when in CMOS Mode
Driver
0 = Disable Inverted CMOS Driver (Default)
1 = Enable Inverted CMOS Driver
OUT4
(OUT5)
(OUT6)
(OUT7)
<7:5>
Not Used
<7:0>
Not Used
Rev. A | Page 53 of 60
AD9510
Reg.
Addr.
(Hex) Bit(s) Name
45
<0> Clock Select
45
45
45
<1>
<2>
<3>
45
45
<4>
<5>
45
46
47
<7:6>
<7:0>
<7:0>
<3:0>
48
(4A)
(4C)
(4E)
(50)
(52)
(54)
(56)
<7:4>
48
(4A)
(4C)
(4E)
(50)
(52)
(54)
(56)
<3:0>
49
(4B)
(4D)
(4F)
(51)
(53)
(55)
(57)
<4>
49
(4B)
(4D)
(4F)
(51)
(53)
(55)
(57)
Description
0: CLK2 Drives Distribution Section
1: CLK1 Drives Distribution Section (Default)
CLK1 Power-Down 1 = CLK1 Input Is Powered Down (Default = 0b)
CLK2 Power-Down 1 = CLK2 Input Is Powered Down (Default = 0b)
1 = Shut Down Clock Signal to PLL Prescaler (Default = 0b)
Prescaler Clock
Power-Down
REFIN Power-Down 1 = Power-Down REFIN (Default = 0b)
All Clock Inputs
1 = Power-Down CLK1 and CLK2 Inputs and Associated Bias and Internal Clock Tree;
Power-Down
(Default = 0b)
Not Used
Not Used
Not Used
Divider High
Number of Clock Cycles Divider Output Stays High
OUT0
(OUT1)
(OUT2)
(OUT3)
(OUT4)
(OUT5)
(OUT6)
(OUT7)
Divider Low
Number of Clock Cycles Divider Output Stays Low
OUT0
(OUT1)
(OUT2)
(OUT3)
(OUT4)
(OUT5)
(OUT6)
(OUT7)
Phase Offset
Phase Offset (Default = 0000b)
OUT0
(OUT1)
(OUT2)
(OUT3)
(OUT4)
(OUT5)
(OUT6)
(OUT7)
Start
Selects Start High or Start Low
(Default = 0b)
OUT0
(OUT1)
(OUT2)
(OUT3)
(OUT4)
(OUT5)
(OUT6)
(OUT7)
Rev. A | Page 54 of 60
AD9510
Reg.
Addr.
(Hex) Bit(s) Name
<5> Force
49
(4B)
(4D)
(4F)
(51)
(53)
(55)
(57)
Description
Forces Individual Outputs to the State Specified in Start (Above)
This Function Requires That Nosync (Below) Also Be Set (Default = 0b)
49
(4B)
(4D)
(4F)
(51)
(53)
(55)
(57)
58
<0>
OUT0
(OUT1)
(OUT2)
(OUT3)
(OUT4)
(OUT5)
(OUT6)
(OUT7)
Nosync
Ignore Chip-Level Sync Signal (Default = 0b)
OUT0
(OUT1)
(OUT2)
(OUT3)
(OUT4)
(OUT5)
(OUT6)
(OUT7)
Bypass Divider
Bypass and Power-Down Divider Logic; Route Clock Directly to Output (Default = 0b)
OUT0
(OUT1)
(OUT2)
(OUT3)
(OUT4)
(OUT5)
(OUT6)
(OUT7)
SYNC Detect Enable 1 = Enable SYNC Detect (Default = 0b)
58
<1>
SYNC Select
58
<2>
Soft SYNC
58
<3>
58
<4>
Dist Ref PowerDown
SYNC Power-Down 1 = Power-Down the SYNC (Default = 0b)
58
<6:5> FUNCTION Pin
Select
<6>
49
(4B)
(4D)
(4F)
(51)
(53)
(55)
(57)
<7>
58
59
5A
<7>
<7:0>
<0> Update Registers
5A
END
<7:1>
1 = Raise Flag if Slow Clocks Are Out-of-Sync by 0.5 to 1 High Speed Clock Cycles
0 (Default) = Raise Flag if Slow Clocks Are Out-of-Sync by 1 to 1.5 High Speed Clock Cycles
Soft SYNC bit works the same as the FUNCTION pin when in SYNCB mode, except that this bit’s polarity is
reversed. That is, a high level forces selected outputs into a known state, and a high > low transition
triggers a sync (default = 0b).
1 = Power-Down the References for the Distribution Section (Default = 0b)
<6>
<5>
Function
0
0
RESETB (Default)
0
1
SYNCB
1
0
Test Only; Do Not Use
1
1
PDB
Not Used
Not Used
A 1 written to this bit updates all registers and transfers all serial control port register buffer contents to
the control registers on the next rising SCLK edge. This is a self-clearing bit; a 0 does not have to be
written to clear it.
Not Used
Rev. A | Page 55 of 60
AD9510
POWER SUPPLY
The AD9510 requires a 3.3 V ± 5% power supply for VS.
The tables in the Specifications section give the performance
expected from the AD9510 with the power supply voltage
within this range. The absolute maximum range of −0.3 V −
+3.6 V, with respect to GND, must never be exceeded on
the VS pin.
Good engineering practice should be followed in the layout of
power supply traces and the ground plane of the PCB. The
power supply should be bypassed on the PCB with adequate
capacitance (>10 μF). The AD9510 should be bypassed with
adequate capacitors (0.1 μF) at all power pins as close as
possible to the part. The layout of the AD9510 evaluation board
(AD9510/PCB or AD9510-VCO/PCB) is a good example.
The AD9510 is a complex part that is programmed for its
desired operating configuration by on-chip registers. These
registers are not maintained over a shutdown of external power.
This means that the registers can loose their programmed
values if VS is lost long enough for the internal voltages to
collapse. Careful bypassing should protect the part from
memory loss under normal conditions. Nonetheless, it is
important that the VS power supply not become intermittent,
or the AD9510 risks losing its programming.
The internal bias currents of the AD9510 are set by the RSET and
CPRSET resistors. These resistors should be as close as possible to
the values given as conditions in the Specifications section
(RSET = 4.12 kΩ and CPRSET = 5.1 kΩ). These values are standard
1% resistor values, and should be readily obtainable. The bias
currents set by these resistors determine the logic levels and
operating conditions of the internal blocks of the AD9510. The
performance figures given in the Specifications section assume
that these resistor values are used.
The VCP pin is the supply pin for the charge pump (CP). The
voltage at this pin (VCP) may be from VS up to 5.5 V, as required
to match the tuning voltage range of a specific VCO/VCXO.
This voltage must never exceed the absolute maximum of 6 V.
VCP should also never be allowed to be less than −0.3 V below
VS or GND, whichever is lower.
The exposed metal paddle on the AD9510 package is an
electrical connection, as well as a thermal enhancement. For
the device to function properly, the paddle must be properly
attached to ground (GND). The PCB acts as a heat sink for the
AD9510; therefore, this GND connection should provide a
good thermal path to a larger dissipation area, such as a ground
plane on the PCB. See the layout of the AD9510 evaluation
board (AD9510/PCB or AD9510-VCO/PCB) for a good
example.
POWER MANAGEMENT
The power usage of the AD9510 can be managed to use only the
power required for the functions that are being used. Unused
features and circuitry can be powered down to save power. The
following circuit blocks can be powered down, or are powered
down when not selected (see the Register Map and Description
section):
• The PLL section can be powered down if not needed.
• Any of the dividers are powered down when bypassed—
equivalent to divide-by-one.
• The adjustable delay blocks on OUT5 and OUT6 are powered
down when not selected.
• Any output may be powered down. However, LVPECL
outputs have both a safe and an off condition. When the
LVPECL output is terminated, only the safe shutdown should
be used to protect the LVPECL output devices. This still
consumes some power.
• The entire distribution section can be powered down when
not needed.
Powering down a functional block does not cause the
programming information for that block (in the registers)
to be lost. This means that blocks can be powered on and off
without otherwise having to reprogram the AD9510. However,
synchronization is lost. A SYNC must be issued to
resynchronize (see the Single-Chip Synchronization section).
Rev. A | Page 56 of 60
AD9510
APPLICATIONS
USING THE AD9510 OUTPUTS FOR ADC CLOCK
APPLICATIONS
level, termination) should be considered when selecting the best
clocking/converter solution.
Any high speed analog-to-digital converter (ADC) is extremely
sensitive to the quality of the sampling clock provided by the
user. An ADC can be thought of as a sampling mixer; any noise,
distortion, or timing jitter on the clock is combined with the
desired signal at the A/D output. Clock integrity requirements
scale with the analog input frequency and resolution, with
higher analog input frequency applications at ≥ 14-bit
resolution being the most stringent. The theoretical SNR of an
ADC is limited by the ADC resolution and the jitter on the
sampling clock. Considering an ideal ADC of infinite resolution
where the step size and quantization error can be ignored, the
available SNR can be expressed approximately by
CMOS CLOCK DISTRIBUTION
⎡ 1 ⎤
SNR = 20 × log ⎢
⎥
⎣ 2πftj ⎦
where f is the highest analog frequency being digitized, and tj is
the rms jitter on the sampling clock. Figure 53 shows the
required sampling clock jitter as a function of the analog
frequency and effective number of bits (ENOB).
Point-to-point nets should be designed such that a driver has
one receiver only on the net, if possible. This allows for simple
termination schemes and minimizes ringing due to possible
mismatched impedances on the net. Series termination at the
source is generally required to provide transmission line
matching and/or to reduce current transients at the driver. The
value of the resistor is dependent on the board design and
timing requirements (typically 10 Ω to 100 Ω is used). CMOS
outputs are limited in terms of the capacitive load or trace
length that they can drive. Typically, trace lengths less than
3 inches are recommended to preserve signal rise/fall times and
preserve signal integrity.
1
2πftj
10Ω
18
CMOS
tj = 0.1ps
80
5pF
12
tj = 10ps
60
tj = 100ps
40
MICROSTRIP
14
Figure 54. Series Termination of CMOS Output
8
Termination at the far end of the PCB trace is a second option.
The CMOS outputs of the AD9510 do not supply enough
current to provide a full voltage swing with a low impedance
resistive, far-end termination, as shown in Figure 55. The
far-end termination network should match the PCB trace
impedance and provide the desired switching point. The
reduced signal swing may still meet receiver input requirements
in some applications. This can be useful when driving long
trace lengths on less critical nets.
6
tj = 1ns
4
20
1
3
10
30
GND
10
05046-024
SNR (dB)
tj = 1ps
16
ENOB
100
60.4Ω
1.0 INCH
100
FULL-SCALE SINE WAVE ANALOG INPUT FREQUENCY (MHz)
Figure 53. ENOB and SNR vs. Analog Input Frequency
See Application Notes AN-756 and AN-501 on the ADI website
at www.analog.com.
Many high performance ADCs feature differential clock inputs
to simplify the task of providing the required low jitter clock on
a noisy PCB. (Distributing a single-ended clock on a noisy PCB
can result in coupled noise on the sample clock. Differential
distribution has inherent common-mode rejection, which can
provide superior clock performance in a noisy environment.)
The AD9510 features both LVPECL and LVDS outputs that
provide differential clock outputs, which enable clock solutions
that maximize converter SNR performance. The input
requirements of the ADC (differential or single-ended, logic
Rev. A | Page 57 of 60
VPULLUP = 3.3V
10Ω
50Ω
100Ω
CMOS
OUT4, OUT5, OUT6, OUT7
SELECTED AS CMOS
100Ω
3pF
Figure 55. CMOS Output with Far-End Termination
05046-027
SNR = 20log10
Whenever single-ended CMOS clocking is used, some of the
following general guidelines should be followed.
05046-025
tj = 50fs
120
The AD9510 provides four clock outputs (OUT4 to OUT7),
which are selectable as either CMOS or LVDS levels. When
selected as CMOS, these outputs provide for driving devices
requiring CMOS level logic at their clock inputs.
AD9510
Because of the limitations of single-ended CMOS clocking,
consider using differential outputs when driving high speed
signals over long traces. The AD9510 offers both LVPECL and
LVDS outputs, which are better suited for driving long traces
where the inherent noise immunity of differential signaling
provides superior performance for clocking converters.
LVPECL CLOCK DISTRIBUTION
The low voltage, positive emitter-coupled, logic (LVPECL)
outputs of the AD9510 provide the lowest jitter clock signals
available from the AD9510. The LVPECL outputs (because they
are open emitter) require a dc termination to bias the output
transistors. A simplified equivalent circuit in Figure 41 shows
the LVPECL output stage.
LVDS CLOCK DISTRIBUTION
Low voltage differential signaling (LVDS) is a second
differential output option for the AD9510. LVDS uses a current
mode output stage with several user-selectable current levels.
The normal value (default) for this current is 3.5 mA, which
yields 350 mV output swing across a 100 Ω resistor. The LVDS
outputs meet or exceed all ANSI/TIA/EIA-644 specifications.
A recommended termination circuit for the LVDS outputs is
shown in Figure 58.
3.3V
LVDS
50Ω
LVPECL
127Ω
127Ω
SINGLE-ENDED
(NOT COUPLED)
3.3V
83Ω
05046-030
83Ω
Figure 56. LVPECL Far-End Termination
3.3V
Figure 58. LVDS Output Termination
POWER AND GROUNDING CONSIDERATIONS AND
POWER SUPPLY REJECTION
LVPECL
50Ω
VT = VCC – 1.3V
3.3V
Many applications seek high speed and performance under
less than ideal operating conditions. In these application
circuits, the implementation and construction of the PCB is as
important as the circuit design. Proper RF techniques must be
used for device selection, placement, and routing, as well as for
power supply bypassing and grounding to ensure optimum
performance.
0.1nF
200Ω
0.1nF
DIFFERENTIAL
(COUPLED)
100Ω
LVPECL
200Ω
05046-031
LVPECL
LVDS
See Application Note AN-586 on the ADI website at
www.analog.com for more information on LVDS.
3.3V
3.3V
100Ω
100Ω
DIFFERENTIAL (COUPLED)
05046-032
In most applications, a standard LVPECL far-end termination is
recommended, as shown in Figure 56. The resistor network is
designed to match the transmission line impedance (50 Ω) and
the desired switching threshold (1.3 V).
3.3V
Figure 57. LVPECL with Parallel Transmission Line
Rev. A | Page 58 of 60
AD9510
OUTLINE DIMENSIONS
9.00
BSC SQ
0.60 MAX
0.60 MAX
8.75
BSC SQ
TOP
VIEW
1
(BOTTOM VIEW)
33
32
PIN 1
INDICATOR
*4.85
4.70 SQ
4.55
EXPOSED PAD
0.45
0.40
0.35
12° MAX
64
49
48
PIN 1
INDICATOR
1.00
0.85
0.80
0.30
0.25
0.18
16
17
7.50
REF
0.80 MAX
0.65 TYP
0.05 MAX
0.02 NOM
0.50 BSC
SEATING
PLANE
0.20 REF
*COMPLIANT TO JEDEC STANDARDS MO-220-VMMD
EXCEPT FOR EXPOSED PAD DIMENSION
Figure 59. 64-Lead Lead Frame Chip Scale Package [LFCSP]
9 mm × 9 mm Body (CP-64-1)
Dimensions shown in millimeters
ORDERING GUIDE
Model
AD9510BCPZ 1
AD9510BCPZ-REEL71
AD9510/PCB
AD9510-VCO/PCB
1
Temperature Range
−40°C to +85°C
−40°C to +85°C
Package Description
64-Lead Lead Frame Chip Scale Package (LFCSP)
64-Lead Lead Frame Chip Scale Package (LFCSP)
Evaluation Board Without VCO or VCXO or Loop Filter
Evaluation Board With 245.76 MHz VCXO, Loop Filter
Z = Pb-free part.
Rev. A | Page 59 of 60
Package Option
CP-64-1
CP-64-1
AD9510
NOTES
©2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05046–0–5/05(A)
Rev. A | Page 60 of 60