PLL701-31 Datasheet, PDF (1/5 Pages) PhaseLink Corporation – Low EMI Spread Spectrum Multiplier Clock

PLL701-31
Low EMI Spread Spectrum Multiplier Clock
FEATURE
• Spread Spectrum Clock Generator with 1x
outputs.
• Output frequency ranges: 10MHz to 30MHz.
• Accepts input from crystal or reference clock.
• Selectable Center, Down or Asymmetric Spread
Modulation.
• Selectable Modulation magnitude.
• TTL/CMOS compatible outputs.
• 3.0V (+/-10%) Supply Voltage.
• Low short-term jitter.
• Available in 8-Pin 150mil SOIC.
DESCRIPTION
The PLL701-31 is a Spread Spectrum Clock
Generator designed to reduce EMI in high-speed
digital systems. The device is designed to operate
from a crystal or reference clock input and provides a
1x modulated clock output. Center, Down and
Asymmetric spread types are selectable as well as
the modulation magnitude.
PIN CONFIGURATION
XIN/FIN 1
XOUT/SD*^ 2
SC0^ 3
SC1^ 4
8 VDD
7 SC2^
6 FOUT
5 GND
XIN/FIN = 10 ~ 30 MHz
Note: ^: Internal pull-up resistor (120kΩ for SD, 30 kΩ for
SC0-SC2).
*: The value of SD is latched upon power-up. The
internal pull-up resistor results in a default high value
when no pull-down resistor is connected to this pin
(recommended external pull-down resistor of 27 kΩ).
OUTPUT CLOCK SELECTION
SD SC2 SC1 SC0
Magnitude
0
1
1
0
1
0
0
1
1
0
1
0
1
1
0
0
1
1
0
1
1
1
1
0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
1
3.75%
3.50%
3.75%
3.25%
3.50%
3.75%
3.25%
3.50%
3.75%
0.00%
Notes: A: Asymmetric Spread. D: Down Spread. C: Center Spread.
SST Modulation
Freq.
D
D
A
D
A
Fin / 512
A
C
C
C
Type
-3.75%
-3.50%
+0.125%, -3.625%
-3.25%
+0.125%, -3.375%
+0.25%, -3.5%
+/-1.625 %
+/-1.75%
+/-1.875%
SST OFF
47745 Fremont Blvd., Fremont, California 94538 Tel [phone] Fax [phone] www.phaselink.com Rev 11/28/05 Page 1