ICS ICS1524MT

Integrated
Circuit
Systems, Inc.
ICS1524
Dual Output Phase Controlled SSTL_3/PECL Clock Generator
General Description
Features
The ICS1524 is a low-cost, very high-performance
frequency generator and phase controlled clock synthesizer. It is perfectly suited to phase controlled clock
synthesis and distribution as well as line-locked and
genlocked applications.
•
• 8 kHz to 100 MHz
The ICS1524 offers two channels of clock phase controlled outputs; CLK and DPACLK. These two output
channels have both 250 MHz PECL differential and 150
MHz SSTL_3 single-ended output pins. The CLK output
channel has a fixed phase relationship to the PLL’s input
and the DPACLK uses the Dynamic Phase Adjust circuitry to allow control of the clock phase relative to input
signal.
Optionally, the CLK outputs can operate at half the clock
rate and phase aligned with the DPACLK channel, enabling deMUXing of multiplexed analog-to-digital
converters. The FUNC pin provides either the regenerated input from the phase-locked loop (PLL) divider
chain output or a re-synchronized and sharpened input
HSYNC.
150 MHz single-ended SSTL_3 clock outputs
•
Dynamic Phase Adjust (DPA) for DPACLK
outputs
•
External or internal loop filter selection
•
Uses 3.3 VDC Inputs are 5 volt tolerant.
•
I2C-bus serial interface runs at either low speed
(100 kHz) or high speed (400 kHz).
•
Hardware and Software PLL Lock detection
•
Generic Frequency Synthesis
•
LCD Monitors and Projectors
•
Genlocking Multiple Video Systems
VDDD
VSSD
SDA
SCL
PDEN
EXTFB
HSYNC
EXTFIL
XFILRET
VDDA
VSSA
OSC
1
2
3
4
5
6
7
8
9
10
11
12
ICS1524
Pin Configuration
DPACLK
DPACLK+/FUNC
I2C
•
Applications
CLK
CLK+/-
OSC
250 MHz balanced PECL differential outputs
• 360o Adjustment down to 1/64 clock
increments
Loop
Filter
HSYNC
•
• Software controlled phase adjustment
The advanced PLL uses either its internal programmable feedback divider or an external divider and is
programmed by a standard I2C-bus™ serial interface.
Block Diagram
Wide input frequency range
24
23
22
21
20
19
18
17
16
15
14
13
IREF
CLK+
(PECL)
CLK–
(PECL)
DPACLK+ (PECL)
DPACLK– (PECL)
VSSQ
VDDQ
DPACLK (SSTL)
CLK
(SSTL)
FUNC
(SSTL)
LOCK/REF (SSTL)
I2CADR
24 Pin 300-mil SOIC
2
I C-bus is a trademark of Philips Corporation.
ICS1524 Rev C 01/31/2003
ICS reserves the right to make changes in the device data identified in this
publication without further notice. ICS advises its customers to obtain the
latest version of all device data to verify that any information being relied
upon by the customer is current and accurate.
ICS1524
Document Revision History
Rev A
ICS1523 Rev T Datasheet used as a starting template
New Block Diagram substituted for old 1523 one
Removed reference to CLK / 2 Functionality
Created a set of clock outputs that bypass the DPA
External PDEN is now the IN-SEL MUX control bit
Text descriptions changed to support new 1524 block diagram
Rev B
Replaced page 15 “Layout Guidelines”
Replaced SIOC Package diagram on page 22
“Advanced Status” removed
Redrew front page graphics for clairity
Rev C
Corrected Chip Revision and Chip Version values on page 5
Changed Title on Page 1
Minor format changes to pages 8 and 21
Corrected pin names on page 10
ICS1524 Rev C 01/31/2003
2
Ref_Pol
Reg 0:2
EXTFB
(6)
PD_Pol
Reg 0:1
MUX
0
1
PDen
Reg 0:0
Lock
Logic
En_DLS
Reg 0:7
En_PLS
Reg 0:6
Fbk_Pol
Reg 0:3
Phase/
Freq
Detector
Charge
Pump
PLL_Lock
PFD
Reg 12:1
Reg 1:0-2
Int Filter
MUX
3
SCL
(4)
Func_Sel
Reg 0:5
1
0
MUX
DPA_Res
Reg 5:0-1
PSD
Reg 1:4-5
Out_Scl
Reg 6:6-7
Output
Scaler
DPACLK (17)
OE_Tck
Reg 6:1
+
Dynamic
Phase
Adjust
IREF
(24)
DPACLK+ (21)
DPACLK– (20)
OE-Pck
Reg 6:0
CLK (16)
1
0
MUX
Ck2_Inv
Reg 6:5
OE_T2
Reg 6:3
+
CLK+ (23)
CLK– (22)
OE_P2
Reg 6:2
FUNC (15)
OE_F
Reg 6:4
June 25, 2001
ICS1524
ICS1524 Rev C 01/31/2003
PowerOn
Reset
ICS1524 Block Diagram
PostScaler
Divider
DPA_OS
Reg 4:0-5
FDB1
FDB0 Reg: 3:0-3
2:0-7
Reg
I2CADR
(13)
PECL
Bias
VCO
DPA_Lock
Reg 12:0
Feedback
Divider
I2C
Interface
Filter
Select
Fil_Sel
Reg 4:7
0
SDA
(3)
EXTFIL (8) XFILRET (9)
1
HSYNC
(7)
Fbk_Sel
Reg 0:4
LOCK/REF (14)
PDEN (5)
Osc
Divider
OSC
(12)
Block Diagram
Osc_Div
Reg 7:0-6
ICS1524
Pin Descriptions
PI N NO.
P I N NAME
TYPE
DESCRI PTI ON
C OMME NT S
1
VDDD
P WR
Digital supply
3. 3V t o di gi t a l s e c t i ons
2
VS S D
P WR
Digital ground
Ground for digital sections
3
SDA
I N/ OUT
Se r i a l d a t a
I2C-bus1
4
SCL
IN
Se r i a l c l o c k
I2C-bus1
5
P DEN
IN
PFD e n a b l e
Suspends charge pump1
6
EXTF B
IN
Ex t e r n a l f e e d b a c k
External divider input to PFD1
7
HS YNC
IN
Horizontal sync
Clock input to PLL1
8
EXTF I L
IN
External filter
External PLL loop filter
9
XF I LRET
10
VDDA
P WR
IN
P WR
External filter return
External PLL loop filter return
Analog supply
3. 3V f or a na l og c i r c ui t r y
11
VS S A
Analog ground
Ground for analog circuitry
12
OS C
IN
Oscillator
I n p u t f r o m c r y s t a l o s c i l l a t o r p a c k a g e 1, 2
13
I 2C ADR
IN
I 2C a d d r e s s
Chip I2C address select
Low = 4Dh read, 4Ch write
High = 4Fh read, 4Eh write
14
LOCK/ REF
Lo c k i n d i c a t o r / r e f e r e n c e
Displays PLL or DPA lock or REF input
SSTL
15
F UNC
SSTL
Fu n c t i o n o u t p ut
SSTL_3 selectable HSYNC output
16
CLK
SSTL
Pixel clockt
Non-Delayed SSTL_3 Clock
17
DPACLK
SSTL
DPA Delayed Clock
DPA Delayed SSTL_3 Clock
18
VDDQ
P WR
Output driver supply
3.3V VDD for output drivers
19
VS S Q
P WR
Output driver ground
Ground for output drivers
20
DPACLK–
PECL
DPA Delayed PECL clock -
DPA Delayed Inverted PECL Clock Open drain.
21
DPACLK+
PECL
DPA Delayed PECL clock +
DPA Delayed PECL Clock
Open drain.
22
CLK–
PECL
PECL clock -
Non-Delayed Inverted PECL Clock
Open drain.
23
CLK+
PECL
PECL clock +
Non-Delayed PECL Clock
Open drain.
24
I REF
IN
Reference current
Reference current for PECL outputs
Notes:
1. These LVTTL inputs are 5 V-tolerant.
2. Connect to ground if unused.
ICS1524 Rev C 01/31/2003
4
ICS1524
I2C Register Map Summary
Register
Index
0h
1h
Name
Input Control
Loop Control
Access
R/W
R/W*
2h
FdBk Div 0
R/W*
3h
FdBk Div 1
R/W*
4h
5h
6h
7h
8h
DPA Offset
DPA Control
Output Enables
Osc_Div
Reset
R/W
Bit Name
R/W
Write
Reset
Value
1
Phase Detector Enable
Description
PDen
0
PD_Pol
1
0
Phase Detector Input Select
(0=Disable 1=Enable)
Ref_Pol
2
0
External Reference Polarity
(0=Positive Edge, 1=Negative Edge)
Fbk_Pol
3
0
External Feedback Polarity
(0=Positive Edge, 1=Negative Edge)
Fbk_Sel
4
0
External Feedback Select
Func_Sel
5
0
Function Out Select
(0=Internal Feedback, 1=External)
(0=Recovered HSYNC, 1=Input HSYNC)
EnPLS
6
1
Enable PLL Lock/Ref Status Output
(0=Disable 1=Enable)
EnDLS
7
0
Enable DPA Lock/Ref Status Output
(0=Disable 1=Enable)
PFD0-2
0-2
0
Phase Detector Gain
Reserved
3
0
Reserved
PSD0-1
4-5
0
Post-Scaler Divider
Reserved
6-7
0
Reserved
FBD0-7
0-7
FF
(0 = /2, 1 = /4, 2 = /8, 3 = /16)
PLL FeedBack Divider LSBs (bits 0-7) *
FBD8-11
0-3
F
PLL Feedback Divider MSBs (bits 8-11) *
Reserved
4-7
0
Reserved
DPA_OS0-5
0-5
0
Dynamic Phase Aligner Offset
Reserved
6
0
Reserved
Fil_Sel
7
1
Loop Filter Select
R / W ** DPA_Res0-1
R/W
Bit #
(0=External, 1=Internal)
0-1
3
DPA Resolution
Metal_Rev
2-7
0
Metal Mask Revision Number
(0=16 delay elements, 1=32, 2=Reserved, 3=64)
OE_Pck
0
1
Output Enable for PECL DPACLK
( 0=High Z, 1=Enabled)
OE_Tck
1
1
Output Enable for STTL_3 DPACLK
( 0=High Z, 1=Enabled)
OE_P2
2
1
Output Enable for PECL CLK
( 0=High Z, 1=Enabled)
OE_T2
3
1
Output Enable for STTL_3 CLK
( 0=High Z, 1=Enabled)
OE_F
4
1
Output Enable for STTL_3 FUNC
( 0=High Z, 1=Enabled)
Ck2_Inv
5
0
Select non-delayed CLK (1) or DPA delayed CLK/2 (0) on CLKx pins
Out_Scl
6-7
0
SSTL DPACLK (Pin 17) Scaler (0 = ÷1, 1 = ÷2, 2 = ÷4, 3 = ÷8)
Osc_Div 0-6
0-6
0
Osc Divider modulus
In-Sel
7
1
RESERVED
DPA
0-3
x
Writing xA hex resets DPA and loads working register 5
PLL
4-7
x
Writing 5x hex resets PLL and loads working registers 1-3
10h
Chip Ver
Read
Chip Ver
0-7
18
Chip Version 17 hex
11h
Chip Rev
Read
Chip Rev
0-7
01
Chip Revision C2 hex
12h
Rd_Reg
Read
DPA_Lock
0
N/A
DPA Lock Status
(0=Unlocked, 1=Locked)
PLL_Lock
1
N/A
PLL Lock Status
(0=Unlocked, 1=Locked)
Reserved
2-7
0
Reserved
* Identifies double-buffered registers. Working registers are loaded during software PLL reset.
** Identifies double-buffered register. Working registers are loaded during software DPA reset.
5
ICS1524 Rev C 01/31/2003
ICS1524
Detailed Register Description
Name:
Register:
Index:
Input Control
0h
Read / Write
Bit Name Bit # Reset Value Description
PDen
PD_Pol
Ref_Pol
Fbk_Pol
Fbk_Sel
Func_Sel
EnPLS
EnDLS
0
1
2
3
4
5
6
7
1
0
0
0
0
0
1
0
Phase detector Enable
Phase/Frequency Detector Input MUX Control
Phase/Frequency Detector External Reference Polarity
External Reference Feedback Polarity
External Feedback Select
Function Output Select
Enable PLL Lock Status Output on LOCK/REF pin
Enable DPA Lock Status Output on LOCK/REF pin
Bit
Name
Description
0
PDen
RESERVED
1
PD_Pol
Input MUX Control
2
Ref_Pol
Phase/Frequency Detector External Reference Polarity —
Edge of input signal on which Phase Detector triggers.
0 = Rising Edge (default)
1 = Falling Edge
3
Fbk_Pol
External Reference Feedback Polarity — Edge of EXTFB (pin 6) signal on which
Phase/Frequency Detector triggers when external feedback is used (Reg0 [4]=1).
0 = Positive Edge (default)
1 = Negative Edge
4
Fbk_Sel
External Feedback Select
0 = Internal Feedback (default)
1 = External Feedback
5
Func_Sel
Function Output Select — Selects re-clocked output to FUNC (pin 15).
0 = Recovered HSYNC (default). Regenerated HSYNC output.
1 = External HSYNC. Schmitt-trigger conditioned input from HSYNC (pin 7).
6
EnPLS
Enable LOCK/REF (pin14) Output
7
EnDLS
ICS1524 Rev C 01/31/2003
PD_POL
Bit 1
0
0
1
1
PDen
Pi n 5
0
1
0
1
P h a s e / F r e q u e n cy De t e c t o r
I nput Suppl i e d wi t h. . .
OSC In
HSYNC In
HSYNC In
OSC In
EnPLS EnDLS IN_SEL
LOCK/REF(14)
0
0
N/A
0
0
1
N/A 1 if DPA locked, 0 otherwise
1
0
N / A 1 i f P L L l o c ke d , 0 o t h e r w i s e
Post Schmitt trigger
1
1
0
HSYNC(7) XOR Ref_Pol
1
1
1
Fosc ÷ Osc_Div
6
ICS1524
Name:
Register:
Index:
Loop Control Register
1h
Read / Write*
Bit Name Bit # Reset Value Description
PFD0-2
Reserved
PSD 0-1
Reserved
0-2
3
4-5
6 -7
0
0
0
0
Phase Frequency Detector Gain
Reserved
Post-Scaler Divider
Reserved
Bit
Name
Description
0-2
PFD0-2
Phase/Frequency Detector Gain
3
Reserved
4-5
PSD 0-1
6-7
Bit 2
Bit 1
Bit 0
PFD Ga i n ( µA/ 2π r a d)
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
1
2
4
8
16
32
64
128
Post-Scaler Divider — Divides the output of the VCO to the DPA and Feedback Divider.
Bit 5
Bit 4
PSD Divider
0
0
1
1
0
1
0
1
2 (default)
4
8
16
Reserved
* Double-buffered register. Actual working registers are loaded during software PLL reset.
See register 8h for details.
7
ICS1524 Rev C 01/31/2003
ICS1524
Name:
Register:
Index:
Feedback Divider 0 Register / Feedback Divider 1 Register
2h, 3h
Read / Write*
Bit Name
Index
Bit #
Reset Value
FBD 0-7
2
0 -7
FF
FBD 8 -11
Reserved
3
3
0 -3
4 -7
F
Description
PLL Feedback Divider LSBs (0 -7).* When Bit 0 = 0, then the total
number of clocks per line is even. When Bit 0 = 1, then the total
number of clocks is odd.
PLL Feedback Divider MSBs (8 -11)*
Reserved
The value that is programmed into these two registers, plus a value of 8, defines the total number of clock periods that the ICS
1524 generates between HSYNCs. Program these registers with the total number of horizontal clocks per line minus 8.
Reg 3
2 1
3
Feedback Divider Modulus
0
7
6
5
Reg 2
4 3
2
1
0
+8
=
12 ≤ Feedback Divider Modulus ≤ 4103
* Double-buffered registers. Actual working registers are loaded during software PLL reset.
See Register 8h for details.
Name:
Register:
Index:
DPA Offset Register
4h
Read / Write
Bit Name
Bit # Reset Value
DPA_OS0-5
Reserved
Fil_Sel
Bit
0-5
6
7
Name
0
0
0
Description
Dynamic Phase Adjust Offset
Reserved
Loop Filter Select
Description
0-5
DPA_OS0-5
Dynamic Phase Adjust Offset.
Selects clock edge offset in discrete steps from zero to one clock period minus one step.
Resolution (number of delay elements per clock cycle) is selected by DPA_Res0-1 (Reg 5:0-1).
Note: Offsets equal to or greater than one clock period are neither recommended nor supported.
Example: For DPA_Res0-1=01H, the clock can be delayed from 0 to 31 steps.
7
Fil_Sel
Selects external loop filter (0) or internal loop filter (1).
The use of an external loop filter is strongly recommended for all designs. Typical loop filter
values are 6.8K Ohms for the series resistor, 3300 pF RF-type capacitor for the series capacitor,
and 33 pF for the shunt capacitor.
ICS1524 Rev C 01/31/2003
8
ICS1524
Name:
Register:
Index:
Bit Name
DPA Control Register
5h
Read / Write*
Bit #
Reset Value
0-1
2- 7
3
0
DPA_Res 0-1
Metal_Rev
Description
Dynamic Phase Adjust Resolution Select.
Metal Mask Revision Number.
Bit
Name
Description
0-1
DPA_Res 0 -1
Dynamic Phase Adjust (DPA) Resolution Select.
It is not recommended to use the DPA above 160 MHz.
Bit 1
0
0
1
1
2-7
Metal_Rev
Bit 0
0
1
0
1
CLK Range, MHz
48
24
80
Delay Elements
16
32
Reserved
64
12
160
40
Metal Mask Revision Number.
After power-up, register bits 7:2 must be written with 111111. After this write,
a read indicates the metal mask revision, as below.
Revision
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
A
B
C1
C2
D
E
F
G
1
0
1
0
1
1
1
1
1
1
0
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
0
1
1
1
1
1
1
1
1
0
* Double-buffered register. Actual working registers are loaded during software DPA reset.
See register 8h for details.
9
ICS1524 Rev C 01/31/2003
ICS1524
Name:
Register:
Index:
Output Enable Register
6h
Read / Write
Bit Name Bit # Reset Value Description
OE_Pck
OE_Tck
OE_P2
OE_T2
OE_F
Sel_1X
Out_Scl
0
1
2
3
4
5
6-7
0
0
0
0
0
0
0
Output Enable for DPACLK Outputs (PECL, Pins 21, 20 )
Output Enable for DPACLK Output (SSTL_3 Pin 17)
Output Enable for CLK Outputs (PECL, Pins 23, 22)
Output Enable for CLK Output (SSTL_3, Pin 16)
Output Enable for FUNC Output (SSTL_3, Pin 15)
Select CLK Output Source (Pins 23, 22, 16)
CLK Output Scaler (SSTL_3, Pin 16)
Bit
Name
Description
0
OE_Pck
Output Enable for DPACLK Outputs (PECL)
0 = High Z
1 = Enabled
1
OE_Tck
Output Enable for DPACLK Output (SSTL_3)
0 = High Z
1 = Enabled
2
OE_P2
Output Enable for CLK Outputs (PECL)
0 = High Z
1 = Enabled
3
OE_T2
Output Enable for CLK Output (SSTL_3)
0 = High Z
1 = Enabled
4
OE_F
Output Enable for FUNC Output (SSTL_3)
0 = High Z
1 = Enabled
5
Ck2_Inv
Select CLK Output Source (Pins 23, 22, 16)
0 = Half Speed DPA Delayed clock to CLK outputs
1 = Full Speed non-DPA Delayed clock to CLK outputs
6 -7
Out_Scl
Clock (CLK, pin 16) Scaler
ICS1524 Rev C 01/31/2003
Bit 7
Bit 6
CLK Divider
0
0
1
1
0
1
0
1
1
2
4
8
10
ICS1524
Name:
Register:
Index:
Oscillator Divider Register
7h
Read / Write
Bit Name
Bit #
Reset Value
Osc_Div 0-6
In_Sel
0-6
7
0
1
Description
Osc Divider Modulus
Input Select
Bit
Name
Description
0-6
Osc_Div 0-6
Oscillator Divider Modulus.
Divides the input from OSC (pin 12) by the set modulus.
The modulus equals the programmed value, plus 2.
Therefore, the modulus range is from 3 to 129.
7
In_Sel
Input Select — Selects the input to the Phase/Frequency Detector
0 = HSYNC
1 = Osc Divider
Name:
Register:
Index:
RESET Register
8h
Write
Bit Name
Bit #
Reset Value
DPA Reset
PLL Reset
0 -3
4 -7
x
x
Description
Writing xAh to this register resets DPA working register 5
Writing 5xh to this register resets PLL working registers 1-3
Bit
Name
Description
0 -3
DPA
Writing xAh to this register resets DPA working register 5
4 -7
PLL
Writing 5xh to this register resets PLL working registers 1-3
Value
Resets
xA
5x
5A
DPA
PLL
DPA and PLL
11
ICS1524 Rev C 01/31/2003
ICS1524
Name:
Register:
Index:
Bit Name
Chip Version Register
10 h
Read
Bit #
Reset Value
0-7
17
Chip Ver
Name:
Register:
Index:
Bit Name
Bit Name
DPA_Lock
PLL_Lock
Reserved
Chip Version 24 (18h )
Chip Revision Register
11h
Read
Bit #
Reset Value
0 -7
01+
Chip Rev
Name:
Register:
Index:
Description
Description
Initial value 01h.
+Value increments with each all-layer change.
Status Register
12 h
Read
Bit # Reset Value
0
1
2 -7
N/A
N/A
0
Description
DPA Lock Status
PLL Lock Status
Reserved
Bit
Name
Description
0
DPA_Lock
DPA Lock Status. (Refer to Register 0h, bits 6 and 7.)
0 = Unlocked
1 = Locked
1
PLL_Lock
PLL Lock Status. (Refer to Register 0h, bits 6 and 7.)
0 = Unlocked
1 = Locked
2 -7
Reserved
ICS1524 Rev C 01/31/2003
12
ICS1524
I2C Data Characteristics
Bit transfer on the I2C-bus
START and STOP conditions
Acknowledge on the I2C-bus
These waveforms are from "The I2 C-bus and how to use it," published by Philips Semiconductor.
The document can be obtained from http://www-us2.semiconductors.philips.com/acrobat/various/i2c_bus_specification_1995.pdf
13
ICS1524 Rev C 01/31/2003
ICS1524
I2C Data Format
RANDOM REGISTER WRITE PROCEDURE
S 0 1 0 0 1 1 x W A
7 bit address
START condition
A
register address
Acknowledge
WRITE command
A P
data
Acknowledge
STOP condition
Acknowledge
RANDOM REGISTER READ PROCEDURE
S 0 1 0 0 1 1 X W A
7 bit address
START condition
register address
Acknowledge
WRITE command
A S 0 1 0 0 1 1 X R A
7 bit address
data
Repeat START
Acknowledge
Acknowledge
READ command
A P
STOP condition
NO Acknowledge
SEQUENTIAL REGISTER WRITE PROCEDURE
S 0 1 0 0 1 1 X W A
7 bit address
START condition
A
register address
Acknowledge
WRITE command
A
data
Acknowledge
A
data
Acknowledge
A P
Acknowledge Acknowledge
STOP condition
SEQUENTIAL REGISTER READ PROCEDURE
S 0 1 0 0 1 1 X W A
7 bit address
START condition
Direction:
register address
Acknowledge
WRITE command
From bus host to device
A S 0 1 0 0 1 1 X R A
7 bit address
data
Repeat START
Acknowledge
Acknowledge
READ command
A
A P
data
NO Acknowledge
Acknowledge STOP condition
From device to bus host
Note:
1.
All values are transmitted with the most-significant bit first and the least-significant bit last.
2.
The value of the X bit equals the logic state of pin 13 (I2CADR).
3.
R = READ = 1 and W = WRITE = 0
ICS1524 Rev C 01/31/2003
14
ICS1524
General Layout Guidelines
•
Use a PC board with at least four layers: one power, one ground, and two signal.
•
Use at least one 4.7 uF Tantalum (or similar) capacitor for global VDD bulk decoupling.
•
All supply voltages must be supplied from a common source and must ramp together.
•
Any flux or other board surface debris can degrade the performance of the external loop filter.
•
Ensure that the 1524 area of the board is free of contaminants.
Specific Layout Guidelines
1. Digital Supply (VDD) – Bypass pin 1 (VDD) to pin 2 (VSS) a 0.1-µF capacitor, located as close as possible to the pins. A
0.01-µF capacitor may be added for additional high frequency rejection.
2. External Loop Filter – Strongly recommended in All Designs. Locate loop filter components as close to pins 8 and 9
(EXTFIL and EXTFILRET) as possible with minimum length traces. Typical loop filter values are 6.8K Ohms for the series
resistor, 3300 pF RF-type capacitor for the series capacitor, and 33 pF for the shunt capacitor. (For details, see the Frequently
Asked Questions part of the ICS1523 Applications Guide, FAQ2 and FAQ3.) A ground isolated, surface trace can be useful to
isolate this section from the rest of the board.
3. Analog PLL Supply (VDDA) – Decouple main VDD from pin 10 (VDDA) with a series ferrite bead. Bypass the supply end of
the bead with 4.7-µF. Bypass pin 10 to pin 11 (VSSA) with a 0.1-µF capacitor. A 0.01-µF capacitor may be added for additional
high frequency rejection. Locate these components as close as possible to the pins.
4. PECL Current Set Resistor – Locate PECL current-set resistor as close as possible to pin 24 (IREF). Bypass pin 24 to
ground with a 0.1 -µF capacitor.
5. .PECL Outputs – Implement these outputs as microstrip transmission lines. The trace widths shown are for 75 Ohm characteristic impedance. Locate any optional series “snubbing” resistors as close as possible to the source pins. If the termination
resistors are included on-board, locate them as close as possible to the load and connect directly to the power and ground
planes.
[These termination resistors are omitted if the load device implements them internally. For details, see the ICS application
note on microstrip and striplines (1572AN1) and within the ICS1523 Applications Guide, the application note on Designing
a Custom Interface for the ICS1523 (1523AN4.)]
6. Output Driver Supply – Bypass pin 18 (VDDQ) to pin 19 (VSSQ) with a 0.1-µF capacitor, located as close as possible to the
pins. A 0.01-µF capacitor may be added for additional high frequency rejection.
7. SSTL_3 Outputs – SSTL_3 outputs can be used like conventional CMOS rail-to-rail logic or as a terminated transmission
line system at higher-output frequencies. With terminated outputs, the considerations of item 5, “PECL Outputs” apply. See
JEDEC documents JESD8-A and JESD8-8.
15
ICS1524 Rev C 01/31/2003
ICS1524
PECL Outputs
For information on using the ICS1524’s PECL output pins, please refer to Application Note 4: Designing a Custom
PECL Interface for the ICS1523
SSTL_3 Outputs
Unterminated Outputs
In the ICS1524, unterminated SSTL_3 output pins display exponential transitions similar to those of rectangular
pulses presented to RC loads. The 10-90% rise time is typically 1.6 ns, and the corresponding fall time is typically
700 ps. In turn, this asymmetry contributes to duty cycle asymmetry at higher output frequencies. In the absence of
significant load capacitance (which can further increase rise and fall time), this asymmetry is the dominant factor
determining high-frequency performance of these single-ended outputs. Typically, no termination is required either
for the LOCK/REF, FUNC, and CLK/2 outputs or for CLK outputs up to approximately 135 MHz.
Terminated Outputs
SSTL_3 outputs are intended to terminate in low impedances to reduce the effect of external circuit capacitance.
Use of transmission line techniques enables use of longer traces between source and driver without increasing ringing due to reflections. Where external capacitance is minimal and substantial voltage swing is required to meet
LVTTL VIH and VOL requirements, the intrinsic rise and fall times of ICS1524 SSTL outputs are only slightly improved
by termination in a low impedance.
The ICS1524 SSTL output source impedance is typically less than 60 Ohms. Termination impedance of 100 Ohms
reduces output swing by less than 30% which is more than enough to drive a single load of LVTTL inputs.
VDD
ICS1524
SSTL-3 Output
330Ω
150Ω
Single
LVTTL
Load
For more information on using the ICS1524’s SSTL output pins, please refer to Application Note 3: Using SSTL_3
Outputs with CMOS or LVTTL Inputs
ICS1524 Rev C 01/31/2003
16
ICS1524
Power Supply Considerations
The ICS1524 incorporates special internal power-on reset circuitry that requires no external reset signal connection. The supply voltage (VDD) must remain within the recommended operating conditions during normal operation. To reset the ICS1524,
the supply voltage at the part must be reduced below the threshold voltage (Vth) of the power-on reset circuit. The supply voltage must remain below that threshold voltage such that board power conditioning capacitors are drained and the proper reset
state is latched. The amount of time (td) to hold the voltage in a reset state varies with the design. However, a typical value of
10 ms should be sufficient.
Supply
Voltage
Vmin
td
Vth = 1.8V
Absolute Maximum Ratings
VDD, VDDA, VDDQ (measured to VSS) . . . . . . . . . . . . . . . . . .
Digital Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Digital Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Soldering Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4.3V
VSS – 0.3V to 5.5V
VSSA – 0.3V to VDDA +0.3V
VSSQ – 0.3V to VDDQ +0.3V
– 65°C to +150°C
175°C
260°C
ESD Susceptibility* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . > 2 KV
(*Electrostatic-sensitive devices. Do not open or handle except in a static-free workstation.)
17
ICS1524 Rev C 01/31/2003
ICS1524
Recommended Operating Conditions
VDD, VDDQ, VDDA (measured to VSS) . 3.0 to 3.6 V
Operating Temperature (Ambient) . . . . . . 0 to +70°C
DC Supply Current
MI N
MAX
UNI TS
Supply Current, Digital
PA R A ME T E R
S YMB OL
I DDD
VDDD = 3.6V
CONDI TI ONS
—
25
mA
Supply Current, Output Drivers
I DDQ
VDDQ = 3.6V, no output drivers enabled.
—
6
mA
Supply Current, Analog
I DDA
VDDA = 3.6V
—
5
mA
Digital Inputs (SDA, SCL, PDEN, EXTFB, HSYNC, OSC, I 2C ADR)
MI N
MA X
UNI T S
Input High Voltage
PA R A ME T E R
S YMB OL
VI H
CONDI TI ONS
2
5. 5
V
Input Low Voltage
VI L
VS S - 0 . 3
0. 8
V
Input Hysteresis
0. 2
0. 6
V
IIH
VIH = VDD
—
± 10
µA
Input Low Current
IIL
VIL = 0
—
± 200
µA
Input Capacitance
Ci n
—
10
pF
MI N
MA X
UNI T S
0. 4
V
MI N
MA X
UNI T S
IOUT = 0
—
VDD
V
VDDD = 3.3V
—
250
MH z
IOUT = programmed value
1. 0
—
V
Input High Current
SDA (In Output Mode: SDA is Bidirectional)
PA R A ME T E R
Output Low Voltage
S YMB OL
VOL
CONDI TI ONS
IOUT = 3 mA. VOH = 6.0V maximum as
determined by the external pull-up resistor.
PECL Outputs (DPACLK+, DPACLK–, CLK+, CLK -)
PA R A ME T E R
Output High Voltage
Maximum Output Frequency
Output Low Voltage
(Note: VOL must not fall below
the level given so that the correct
value for IOUT can be
maintained.)
S YMB OL
VOH
Fp MAX
VOL
CONDI TI ONS
SSTL-3 Outputs (DPACLK, CLK, FUNC, LOCK/REF)
PA R A ME T E R
Output Resistance
Maximum Output Frequency
S YMB OL
RO
Fs MAX
MI N
MA X
UNI T S
1 <VO<2V
CONDI TI ONS
—
80
VDDD = 3.3V
—
150
Ω
MH z
UNI T S
AC Input Characteristics
PA R A ME T E R
HSYNC Input Frequency
OSC Input Frequency
ICS1524 Rev C 01/31/2003
S YMB OL
MI N
MA X
fHSYNC
CONDI TI ONS
. 008
10
MH z
fOSC
. 02
100
MH z
18
ICS1524
VCO Output Frequency and Intrinsic Jitter
700
700
600
600
Frequency (Slow: 3.0V @ 70ºC)
Frequency (Nominal: 3.3V @ 30ºC)
Frequency (Fast: 3.6V @ 0ºC)
500
500
Jitter (3.0V @ 70ºC)
Jitter (3.6V @ 0ºC)
400
400
Frequency
300
300
200
200
Jitter
100
100
0
0
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
2.6
2.8
3
3.2
VCO Voltage
Note: Measured with an Externally Forced Filter Voltage
19
ICS1524 Rev C 01/31/2003
Jitter (ps)
VCO Frequency (MHz)
Jitter (3.3V @ 30ºC)
ICS1524
ns Delay
DPA Delay-16 Element Resolution
20
18
16
14
12
10
8
6
4
2
0
50 MHz - SVGA @ 72 Hz
157.5 MHz - SXGA @ 85 Hz
0
4
8
16
12
DPA Setting
DPA Delay - 32 Element Resolution
45
ns Delay
40
35
25.175 MHz - VGA @ 60 Hz
30
78.75 MHz - XGA @ 75 Hz
25
20
15
10
5
0
0
4
8
12
16
20
24
32
28
DPA Setting
DPA Delay - 64 Element Resolution
90
80
ns Delay
70
12.27 MHz - NTSC
60
39.8 MHz - SVGA @ 60
50
40
30
20
10
0
0
4
8
12
16
20
24
28
32
36
DPA Setting
Note:
Maximum number of data points used for this graph.
ICS1524 Rev C 01/31/2003
20
40
44
48
52
56
60
64
ICS1524
t0
Output Timing Diagram
HSYNC
REF
PECL CLKPECL CLK+
tR
t3
t2
t1
tS
tp
t8
t4
t9
SSTL-CLK
tF
FUNC_OUT
t5
tDPA
t1
PECL DPACLKPECL DPACLK+
tS
t3
t2
t4
tp
t8
t9
SSTL-DPACLK
tF
FUNC
Typical Transition Times*
Symbol
Timing Description
Rise
Fall
Units
tR
REF
2.8
1.8
ns
tP
PECL CLK
1.0
1.2
ns
tS
tF
SSTL-CLK
FUNC_OUT
1.6
1.2
0.7
1.0
ns
ns
Output Timing*
Symbol
Timing Description
Min
Typ
Max
Units
t0
HSYNC to REF delay
11.3
11.5
12
ns
t1
REF to PECL clock delay
-1.0
0.8
2.2
ns
t2, t3
PECL clock duty cycle
45
50
55
%
t4
PECL clock to SSTL_3 clock delay
0.2
0.75
1.2
ns
t5
PECL clock to FUNC_OUT delay
1.5
1.9
2.3
ns
t6
PECL clock to PECL/2 clock
1.0
1.3
1.5
ns
t7
PECL clock to SSTL_3–CLK/2 delay
1.1
1.4
1.8
ns
SSTL clock duty cycle
45
50
55
%
t8, t9
*Note: Measured at 3.6V 0°C, 135-MHz output frequency, PECL clock lines to 75 Οηµ termination, SSTL_3 clock lines
unterminated, 20-pF load. Transition times vary based on termination.
21
ICS1524 Rev C 01/31/2003
ICS1524
24-Pin SOIC (wide body)
Orde ring Information
Part/Orde r
N umbe r
M arking
Package
Shipping
IC S1524M
IC S1524M
SIO C - 24
Tubes
IC S1524MT
IC S1524M
SIO C - 24
Tape and Reel
While the information presented herein has been checked for both accuracy and reliability, Integrated Circuit Systems, Incorporated (ICS) assumes no responsibility for either its use or
for infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal
commercial applications. Any other applications such as those requiring extended temperature range, high reliability, or other extraordinary environmental requirements are not recommended without additional processing by ICS. ICS reserves the right to change any circuitry or specifications without notice. ICS does not authorize or warrant any ICS product for use in
life support devices or critical medical instruments.
ICS1524 Rev C 01/31/2003
22
ICS1524
NOTES
23
ICS1524 Rev C 01/31/2003
ICS1524
Integrated Circuit Systems, Inc.
Corporate Headquarters:
2435 Boulevard of the Generals
P.O. Box 968
Valley Forge, PA 19482-0968
Telephone: 610-630-5300
Fax: 610-630-5399
San Jose Operations:
525 Race Street
San Jose, CA 95126-3448
Telephone: 408-297-1201
Fax:
408-925-9460
Web Site:
http://www.icst.com
ICS1524 Rev C 01/31/2003
24