PicoEMI Programmable Spread Spectrum Clock

PicoEMI T M Programmable Spread Spectrum Clock
FEATURES
DESCRIPTION
 Advanced programmable Spread Spectrum clock
generator with 16 modulation steps to choose from
 Programmable SST 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
 Input Frequency Range:
o Fundamental Crystal: 10MHz to 40MHz
 Output Frequency Range:
o 1MHz to 200MHz @ 3.3V operation
o 1MHz to 166MHz @ 2.5V operation
 Programmable Output Drive (4mA, 8mA, 16mA)
 Low Cycle to Cycle jitter, 100pS
 Single 2.5V to 3.3V, ± 10% power supply
 Available in Die form
The PL671-00 is an advanced programmable Spread
Spectrum clock generator (PSSCG), and a member of
PhaseLink’s PicoPLL Programmable Clock family.
The PL671-00 clock outputs can be programmed up to
200MHz (3.3V) or 166MHz (2.5V), and has 16 modulation
magnitudes (±0.125 to ±2.0% or -0.25 to -4.0%) to choose
from for use in Center or Down Spread modulation
applications. In addition, 2 configuration pins can be
programmed to allow cycling the device through 4 preprogrammed states*. The option of being able to turn
‘ON/OFF’ the Spread Spectrum modulation allows for
completing a design with PL671-00 and having the assurance
of turning ‘ON’ the EMI modulation if EMI becomes an issue*.
The PL671-00’s spread spectrum modulation greatly
reduces the fundamental and harmonic frequencies’
peak magnitude, reducing the system level
electromagnetic radiation by as much as 20dB.
*Note: Requires 6-pad package
PAD CONFIGURATION
DIE SPECIFICATION
0.80mm
XIN
Parameter
XOUT
OE^, PDB^,
CLK1
CSEL1^
GND
Value
Chip size
1.40mm x 0.80mm
VDD
Chip thickness
150 to 250µm
CSEL0^, CLK2
PAD size
90µm x 90 µm
CLK0
Chip base
GND level
Note: ^ denotes internal pull up resistor
BLOCK DIAGRAM
XIN
Xtal
Osc
XOUT
PDB
CLK[0:2]
CSEL[0:1]
SST On/Off
Programming
Logic
Modulation Magnitude*
* Optional Pre-defined
Modulation Magnitude Control
Programmable Function
SST
Modulation
FREF
R-Counter
9-bits
M-Counter
11-bits
÷8
÷8
Phase
Detector
Charge
Pump
Loop
Filter
VCO
FVCO = FREF * (M/R)
P-Counter
6-bits
Odd/Even
FOUT = FVCO / P
CLK1/PDB
CLK0
/1, /2
/1, /2, /4
CLK2/CSEL0
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PicoEMI T M Programmable Spread Spectrum Clock
PAD ASSIGNMENT AND DESCRIPTION
Name
Pad Assignment*
Type
Description
1286
I
Crystal input pad.
This pin can be programmed to function as OE (input), PDB (input)
or CLK1 (output).
Output Enable (OE) input. Enables and disables the clock output
buffer. Internal pull up resistor.
Power Down (PDB) input. Turns off the oscillator, PLL and the
output when pulled to logic “0”. Internal pull up resistor.
930
I/O
Pad #
X (µm)
Y (µm)
XIN
1
124
OE, PDB,
CLK1
2
87
Pin State
OE
PDB
0
Disable CLK
Power Down Mode
1 (default)
Normal mode
Normal mode
Clock1 (CLK1) output. This optional clock can be set to F REF ,
F REF /2 or F OUT (Programmable PLL output).
CSEL1
3
87
628
I
Optional programming of CSEL0 & CSEL1 input pins allow
switching between ‘4’ pre-defined configurations. Internal pull up
resistor.
GND
4
87
275
P
GND connection
CLK0
5
714
380
O
Programmable Clock Output
CSEL0,
CLK2
6
714
677
I
This pin can be programmed to function as CSEL0 (input) or CLK2
(output).
CSEL0 input. Optional programming of CSEL0 & CSEL1 input
pins allow switching between ‘4’ pre-defined configurations.
Internal pull up resistor.
CLK2 output. This optional clock can be set to F REF , CLK0,
CLK0/2 or CLK0/4.
VDD
7
714
916
P
VDD connection
XOUT
8
677
1286
O
Crystal output pad. See Crystal Specifications on page 6.
* Note: The X/Y coordinates indicate pad centers referenced from the lower left corner of the die.
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 12/22/08 Page 2
PicoEMI T M Programmable Spread Spectrum Clock
KEY PROGRAMMING PARAMETERS
CLK[ 0:2 ]
Output Frequency
SST Modulation Magnitude
(Spread Percentage)
F OUT = F REF * M / (R * P)
16 programmable modulation
where M =11 bit
magnitudes to choose from:
R = 9 bit
P = 6 bit
 Center Spread: ±0.125% to
 CLK0= F REF , F REF /2 or F VCO /P*
±2.0% in ±0.125% steps
 CLK1= F REF , F REF /2 or F VCO /P*  Down Spread: -0.25% to
-4.0% in 0.25% steps
 CLK2= F REF , CLK0, CLK0/2
or CLK0/4
 SST On/Off Control.
Programmable
Input/Output
Programmable I/O’s include:
 PDB – input
 Optional CSEL0, CSEL1
(Pre-defined configurations)
– input
 SST On/Off control – input
 CLK[0:2] - output
Output Drive
Strength
Three optional
drive
strengths to
choose from:
Low: 4mA
Std: 8mA
(default)
High: 16mA
* ‘P’ is a 6-bit Odd/Even divider.
FUNCTIONAL DESCRIPTION
PL671-00 is a highly featured, very flexible, advanced programmable PLL design for high performance, low-power
Spread Spectrum modulation applications. The PL671-00 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 PL671-00 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 PL671-00 are mentioned below.
PLL Programming
The PLL in the PL671-00 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 PL671-00 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%
±0.125%
Down Spread
-0.25% thru -4.00%
0.25%
Clock Outputs (CLK[0:2])
CLK0 is the main clock output. The PL671-00 can
also be programmed with additional clock outputs
CLK1 and CLK2. The outputs of CLK[0:2] can be
configured as described below:



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) Frequency
FOUT = FREF * M / (R * P)
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).
Modulation Rate
The PL671-00 modulation rate is defined as F REF
(Crystal 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.
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 12/22/08 Page 3
PicoEMI T M Programmable Spread Spectrum Clock
Output Enable Control (OE)
When activated (logic ‘0’), OE disables the clock
output buffer putting it into a Hi-Z state. The PDB
input incorporates a pull up resistor giving a default
condition of logic “1”.
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 PL671-00 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 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.
ELECTRICAL SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
PARAMETERS
SYMBOL
MIN
MAX
UNITS
V DD
-0.5
7
V
Input Voltage Range
VI
-0.5
V DD +0.5
V
Output Voltage Range
VO
-0.5
V DD +0.5
V
Supply Voltage Range
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
CONDITIONS
Crystal Input Frequency(XIN) Fundamental Crystal
Output Frequency
Settling Time
Output Enable Time
Output Rise Time
Output Fall Time
@ VDD =3.3V
@ VDD =2.5V
MIN
TYP
10
MAX
UNITS
40
MHz
200
1
166
At power-up (after VDD increases over 2.25V)
OE Function; Ta=25º C, 15pF Load. Add one
clock period to this measurement for a
usable output.
PDB Function; Ta=25º C, 15pF Load
MHz
2
ms
10
ns
2
ms
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
1.7
2.5
15pF Load, 90/10% V DD , High Drive
1.2
1.7
ns
ns
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PicoEMI T M Programmable Spread Spectrum Clock
AC SPECIFICATIONS (Continued)
PARAMETERS
CONDITIONS
MIN
TYP
MAX
UNITS
45
50
55
%
100
ps
MAX
UNITS
27MHz, 3.3V, load=15pF, (PDB=1)
15
mA
PDB=0
10
A
3.63
V
100
ms
0.4
V
Duty Cycle
At V DD /2
Cycle to Cycle Jitter*
TCYC-CYC Over output frequency range @ 3.3V
* Note: Jitter performance depends on the programming parameters.
DC SPECIFICATIONS
PARAMETERS
SYMBOL
CONDITIONS
MIN
TYP
Supply Current, Dynamic,
with Loaded Outputs
I DD
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, Std 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
2.25
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
Low C0
UNITS
14
Maximum Sustainable Drive Level
High C0
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 12/22/08 Page 5
PicoEMI T M Programmable Spread Spectrum Clock
ORDERING INFORMATION
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 ordering number for this device is a combination of the following:
Part number, Package type and Operating temperature range
Part Number
Package Type
D=Die
W=Wafer
Temperature
C=Commercial (0°C to 70°C)
Part / Order Number
Marking
Package Option
PL671-00DC
PL671-00DC
Die (Waffle pack)
PL671-00WC
PL671-00WC
Wafer
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.
47745 Fremont Blvd., Fremont, California 94538 Tel (510) 492-0990 Fax (510) 492-0991 www.phaselink.com Rev 12/22/08 Page 6