PicoEMI Programmable Spread Spectrum Clock

PicoEMI T M Programmable Spread Spectrum Clock
FEATURES
DESCRIPTION
 Advanced programmable PLL with Spread Spectrum
 Crystal or Reference Clock input
o Fundamental crystal: 10MHz to 40MHz
o Reference input: 1MHz to 200MHz
 Accepts ≥0.1V reference signal input voltage
 Output frequency range: up to 166MHz @ 2.5V or
up to 200MHz @ 3.3V operation
 Up to 3 programmable outputs
 Programmable Spread Spectrum Modulation
Magnitude:
o Center Spread: ±0.125% to ±2.0% in ±0.125%
steps
o Down Spread: -0.25% to -4.0% in 0.25% steps
 Spread Spectrum On/Off selection
 Programmable output drive (4mA, 8mA, 16mA)
 Low Cycle to Cycle jitter.
 Single 2.5V to 3.3V, ± 10% power supply
 Operating temperature range from -40C to 85C
 Available in 8-pin SOP, MSOP and 6-pin SOT
GREEN/RoHS compliant packaging
The PL671-01 is an advanced programmable Spread
Spectrum clock generator (PSSCG), and a member
of PhaseLink’s PicoPLL™ Programmable Clock
family.
The PL671-01 offers up to three 200MHz outputs,
and allows for programming the modulation type
(Center or Down Spread) as well as 16 modulation
magnitudes (±0.125% to ±2.0% or -0.25% to -4.0%).
In addition, the CSEL[0:1] pins can be used to toggle
the device thru 4 pre-programmed configurations.
The option of being able to turn ‘ON/OFF’ the
Spread Spectrum modulation allows for completing a
design with PL671-01 and having the assurance of
turning ‘ON’ the EMI modulation, if EMI becomes an
issue. The PL671-01’s frequency modulation
greatly reduces the fundamental and harmonic
frequencies’ peak magnitude, therefore reducing the
system level Electro Magnetic Interference (EMI), by
as much as 20dB
PIN CONFIGURATION
XIN, FIN
1
8
XOUT
PDB^, CLK1
2
7
VDD
CSEL1^
3
6
CSEL0^, CLK2
GND
4
5
CLK0
(M)SOP-8L
Note: ^ Denotes 60KΩ Pull-up resistor
BLOCK DIAGRAM
SST
Modulation
Xtal
Osc
Modulation Magnitude*
PDB
R-Counter
9-bits
M-Counter
11-bits
CSEL[0:1]
* Optional Pre-defined
Modulation Magnitude Control
Programmable Function
÷8
Phase
Detector
Charge
Pump
Loop
Filter
VCO
FVCO = FREF * (M/R)
CLK[0:2]
SST On/Off
÷8
P-Counter
6-bits
Odd/Even
FOUT = FVCO / P
/1, /2
/1, /2, /4
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PicoEMI T M Programmable Spread Spectrum Clock
KEY PROGRAMMING PARAMETERS
CLK[ 0:2 ]
Output Frequency
SST Modulation Magnitude
(Spread Percentage)
FOUT = FREF * M / (R * P)
where M =11 bit
R = 9 bit
P = 6 bit
 CLK0= FREF, FREF/2 or FVCO/P*
 CLK1= FREF, FREF/2 or FVCO/P*
 CLK2= FREF, CLK0, CLK0/2 or CLK0/4
Programmable
Input/Output
Output Drive
Strength
16 programmable modulation
magnitudes to choose from:
Programmable I/O’s
include:
 Center Spread: ±0.125% to
±2.0% in ±0.125% steps
 Down Spread: -0.25% to
-4.0% in 0.25% steps
 SST On/Off Control.
 PDB – input
 CSEL[0:1] Configuration
Selection - input
 CLK[0:2] - output
Three optional
drive strengths
to choose from:
Low: 4mA
Std: 8mA
(default)
High: 16mA
* ‘P’ is a 6-bit Odd/Even divider.
PACKAGE PIN ASSIGNMENT
Name
XIN, FIN
(M)SOP-8L SOT23-6L
Type
Pin #
Pin #
1
3
I
Description
Crystal or Reference input pin
This pin can be programmed as PDB (input) or CLK1 (output).
Power Down (PDB) input. This pin has an internal 60KΩ pull up
resistor and turns off the oscillator and the output when pulled to
logic “0”.
PDB, CLK1
2
1
I/O
PDB Logic
Osc
PLL
Output
0
Off
Off
Hi Z (Default)
1
Normal Operation (Default)
Clock1 (CLK1) output. This optional clock can be set to F REF ,
F REF /2 or F OUT (Programmable PLL output).
CSEL1
3
-
I
Selector pin used to toggle between two pre-programmed
configurations (When used in conjunction with CSEL0 there are
four possible pre-defined configurations to choose from).
GND
4
2
P
GND connection
CLK0
5
6
O
Programmable Clock Output with spread spectrum.
CSEL0, CLK2
6
-
I/O
This pin can be programmed to function as CSEL0 (input) or
CLK2 (output).
CSEL0 input. Selector pin used to toggle between two preprogrammed configurations (When used in conjunction with
CSEL1 there are four possible pre-defined configurations to
choose from).
CLK2 output. This optional clock can be set to F REF , CLK0,
CLK0/2 or CLK0/4.
VDD
7
5
P
VDD connection (2.25~3.63V)
XOUT
8
4
O
Crystal output pin. Do Not Connect when using FIN.
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PicoEMI T M Programmable Spread Spectrum Clock
FUNCTIONAL DESCRIPTION
PL671-01 is a highly featured, very flexible, advanced programmable PLL design for high performance, low-power
Spread Spectrum modulation applications. The PL671-01 accepts a fundamental input crystal of 10MHz to 40MHz
or a reference clock input of 1MHz to 200MHz and is capable of producing three SST modulated outputs up to
200MHz. This flexible design allows the PL671-01 to deliver any PLL generated frequency, F REF (Crystal or Ref
Clk) frequency or F REF /2 to CLK0, CLK1 and/or CLK2. Alternate configuration using CSEL0 & CSEL1 allows the
device to choose from up to 4 different pre-defined settings providing a range of spread settings, drive levels and
outputs to choose from. Some of the design features of the PL671-01 are mentioned below.
PLL Programming
The PLL in the PL671-01 is fully programmable. The
PLL is equipped with a 9-bit input frequency divider
(R-Counter), and an 11-bit VCO frequency feedback
loop divider (M-Counter). The output of the PLL is
transferred to a 6-bit post VCO Odd/Even divider (PCounter). The output frequency is determined by the
following formula [F OUT = (F REF * M)/(R*P).
Modulation Magnitude and Type
The PL671-01 provides the following programmable
capabilities for Modulation Type and Modulation
Magnitude (Spread Percentage):
Modulation
Type
Modulation
Magnitude
Programming
Steps
Center Spread ±0.125% thru ±2.00%
Down Spread
-0.25% thru -4.00%
±0.125%
0.25%
Modulation Rate
The PL671-01 modulation rate is defined as F REF
(Crystal or Ref Clk Frequency) divided by 8 times the
R-counter, i.e. Modulation Rate = (F REF / 8R). The
rate can be changed by choosing alternate R-Counter
settings.
Clock Outputs (CLK[0:2])
CLK0 is the main clock output. The PL671-01 can
also be programmed with additional clock outputs
CLK1 and CLK2. The outputs of CLK[0:2] can be
configured as described below:



The output drive level of each output can be
independently programmed to Low Drive (4mA),
Standard Drive (8mA) or High Drive (16mA). The
output frequency can be programmed up to 200MHz
at 3.3V (166MHz at 2.5V).
Power-Down Control (PDB)
When activated (logic ‘0’), PDB ‘Disables the PLL,
the oscillator circuitry, counters, and all other active
circuitry. In Power Down mode the IC consumes
<10µA of power. The PDB input incorporates a pull
up resistor giving a default condition of logic “1”.
Configuration Selectors (CSEL[0:1])
The PL671-01 has the capability to be programmed
with 4 distinct configurations and to toggle “On the
Fly” between these configurations using the selector
pads CSEL0 and CSEL1. CSEL0 and CSEL1 both
incorporate a 60kΩ pull up resistor giving a default
condition of logic “1”.
When the CSEL0, CLK2 pin is programmed to be
CLK2, CSEL0 is set to a default of Logic 1. This
means that two programmable configurations are
available to be selected “On the Fly” using CSEL1.
CLK0= FREF, FREF/2 or FVCO/P*
CLK1= FREF, FREF/2 or FVCO/P*
CLK2= FREF, CLK0, CLK0/2 or CLK0/4
Where
F REF - Reference (Crystal or Ref Clk) Frequency
FOUT = FREF * M / (R * P)
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 07/24/09 Page 3
PicoEMI T M Programmable Spread Spectrum Clock
LAYOUT RECOMMENDATIONS
Evaluation Board # EVB67101T-A0
SOT23-6 pin
Evaluation Board # EVB67101S-A0
SOP-8 pin
The following guidelines are to assist you with a performance optimized PCB design:
Signal Integrity and Termination
Considerations
Decoupling and Power Supply
Considerations
- Keep traces short!
- Place decoupling capacitors as close as possible to
the VDD pin(s) to limit noise from the power supply
- Trace = Inductor. With a capacitive load this
equals ringing!
- Long trace = Transmission Line. Without proper
termination this will cause reflections ( looks like
ringing ).
- Design long traces (>1 inch) as “striplines” or
“microstrips” with defined impedance.
- Match trace at one side to avoid reflections
bouncing back and forth.
- Multiple VDD pins should be decoupled separately
for best performance.
- Addition of a ferrite bead in series with VDD can
help prevent noise from other board sources
- Value of decoupling capacitor is frequency
dependant. Typical values to use are 0.1F for
designs using frequencies < 50MHz and 0.01F for
designs using frequencies > 50MHz.
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 07/24/09 Page 4
PicoEMI T M Programmable Spread Spectrum Clock
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 07/24/09 Page 5
PicoEMI T M Programmable Spread Spectrum Clock
ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
PARAMETERS
SYMBOL
MIN.
MAX.
UNITS
V DD
-0.5
4.6
V
Input Voltage Range
VI
-0.5
V DD +0.5
V
Output Voltage Range
VO
-0.5
V DD +0.5
V
260
C
Supply Voltage Range
Soldering Temperature (Green package)
10
Data Retention @ 85C
Storage Temperature
TS
Ambient Operating Temperature*
Year
-65
150
C
-40
85
C
Exposure of the device under conditions beyond the limits specified by Maximum Ratings for extended periods may cause permanent damage to the device
and affect product reliability. These conditions represent a stress rating only, and functional operations of the device at these or any other conditions above
the operational limits noted in this specification is not implied. *Operating temperature is guaranteed by design. Parts are tested to commercial grade only.
AC SPECIFICATIONS
PARAMETERS
Crystal Input Frequency(XIN)
Input (FIN) Frequency
Input (FIN) Signal Amplitude
Input (FIN) Signal Amplitude
Output Frequency
CONDITIONS
Fundamental Crystal
@ V DD =3.3V
@ V DD =2.5V
Internally AC coupled (High Frequency)
Internally AC coupled (Low Frequency)
3.3V <50MHz, 2.5V <40MHz
@ V DD =3.3V
MIN.
TYP.
10
MAX.
UNITS
40
MHz
200
1
166
MHz
0.9
V DD
Vpp
0.1
V DD
Vpp
200
@ V DD =2.5V
166
MHz
Settling Time
At power-up (after V DD increases over 2.25V)
2
ms
Output Enable Time
PDB Function; Ta=25º C, 15pF Load
2
ms
Output Rise Time
Output Fall Time
Duty Cycle
Cycle to Cycle Jitter*
15pF Load, 10/90% V DD , Standard Drive
2.0
3.0
15pF Load, 10/90% V DD , High Drive
1.2
1.7
15pF Load, 90/10% V DD , Standard Drive
2.0
3.0
15pF Load, 90/10% V DD , High Drive
1.2
1.7
50
55
%
100
ps
At V DD / 2
T CYC - CYC Over output frequency range @
3.3V
45
ns
ns
* Note: Jitter performance depends on the programming parameters.
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PicoEMI T M Programmable Spread Spectrum Clock
DC SPECIFICATIONS
PARAMETERS
SYMBOL
CONDITIONS
I DD
At 27MHz, 3.3V,
load=15pF, (PDB=1)
PDB=0 [with reference input
Supply Current, Dynamic
MIN.
TYP.
pin (FIN) pulled down]
2.25
MAX.
UNITS
15
mA
10
A
3.63
V
100
ms
0.4
V
Operating Voltage
V DD
Power Supply Ramp
t PU
Output Low Voltage
V OL
Time for V DD to reach 90%
V DD . Power ramp must be
monotonic.
I OL = +4mA (Std. Drive)
Output High Voltage
V OH
I OH = -4mA (Std. Drive)
V DD – 0.4
V
Output Current, Low Drive
I OSD
V OL = 0.4V, V OH = 2.4V
4
mA
Output Current, Standard Drive
I OSD
V OL = 0.4V, V OH = 2.4V
8
mA
Output Current, High Drive
I OHD
V OL = 0.4V, V OH = 2.4V
16
mA
CRYSTAL SPECIFICATIONS
PARAMETERS
Fundamental Crystal Resonator Frequency
Crystal Loading Rating
SYMBOL
MIN.
F XIN
10
C L (xtal)
TYP.
40
MHz
pF
100
Operating Drive Level
Small SMD Crystal
UNITS
15
Maximum Sustainable Drive Level
Metal Can Crystal
MAX.
W
30
Shunt Capacitance
ESR Max
Shunt Capacitance
ESR Max
W
C0
5.5
pF
ESR
50
Ω
C0
2.5
pF
ESR
80
Ω
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 07/24/09 Page 7
PicoEMI T M Programmable Spread Spectrum Clock
PACKAGE DRAWINGS (GREEN PACKAGE COMPLIANT)
MSOP-8L
Symbol
A
A1
A2
B
C
D
E
H
L
e
Dimension in MM
Min.
Max.
--1.10
0.05
0.15
0.81
0.91
0.25
0.40
0.13
0.23
2.90
3.10
2.90
3.10
4.90 BSC
0.445
0.648
0.65 BSC
E
H
D
A2 A
A1
C
L
b
e
SOP-8L
Symbol
A
A1
A2
B
C
D
E
H
L
e
Dimension in MM
Min.
Max.
1.35
1.75
0.10
0.25
1.25
1.50
0.33
0.53
0.19
0.27
4.80
5.00
3.80
4.00
5.80
6.20
0.40
0.89
1.27 BSC
E
H
D
A2 A
A1
C
L
b
e
SOT23-6L
Symbol
A
A1
A2
b
c
D
E
H
L
e
Dimension in MM
Min.
Max.
1.05
1.35
0.05
0.15
1.00
1.20
0.30
0.50
0.08
0.20
2.80
3.00
1.50
1.70
2.60
3.00
0.35
0.55
0.95 BSC
Pin1 Dot
E
H
D
A2 A
A1
C
e
b
L
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 07/24/09 Page 8
PicoEMI T M Programmable Spread Spectrum Clock
ORDERING INFORMATION (GREEN PACKAGE COMPLIANT)
For part ordering, please contact our Sales Department:
47745 Fremont Blvd., Fremont, CA 94538, USA
Tel: (510) 492-0990 Fax: (510) 492-0991
PART NUMBER
The order number for this device is a combination of the following:
Part Number, Package Type and Operating Temperature Range
Part Number
3 DIGIT ID Code *
(will be assigned at
programming time)
Package Type
M=MSOP-8L
S=SOP-8L
T-SOT23-6L
Shipping Option
None=Tube
R=Tape & Reel
Temperature
C=Commercial (0°C to 70°C)
I=Industrial (-40°C to 85°C)
* PhaseLink will assign a unique 3-digit ID code for each approved programmed part number.
Part/Order Number
Package Option
PL671-01-XXXMC
8-Pin MSOP (Tube)
PL671-01-XXXMC-R
8-Pin MSOP (Tape and Reel)
PL671-01-XXXSC
8-Pin SOP (Tube)
PL671-01-XXXSC-R
8-Pin SOP (Tape and Reel)
PL671-01-XXXTC-R
6-Pin SOT23 (Tape and Reel)
Please visit www.phaselink.com/package.asp for a detailed marking specification.
PhaseLink Corporation, reserves the right to make changes in its products or specifications, or both at any time without notice. The information
furnished by Phaselink is believed to be accurate and reliable. However, PhaseLink makes no guarantee or warranty concerning the accuracy of said
information and shall not be responsible for any loss or damage of whatever nature resulting from the use of, or reliance upon this product.
LIFE SUPPORT POLICY: PhaseLink’s products are not authorized for use as critical components in life support devices or systems without the
express written approval of the President of PhaseLink Corporation.
Solder reflow profile available at www.phaselink.com/QA/solderingGreen.pdf
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 07/24/09 Page 9