ICS844002-01 Datasheet, PDF (1/15 Pages) Integrated Device Technology – FEMTOCLOCKS™ CRYSTAL-TOLVDS FREQUENCY SYNTHESIZER

FEMTOCLOCKS– CRYSTAL-TO-
LVDS FREQUENCY SYNTHESIZER
Description
The ICS844002-01 is a 2 output LVDS Synthesizer
ICS
optimized to generate Ethernet reference clock
HiPerClockS™ _{frequencies and is a member of the HiPerClocks}^TM
family of high performance clock solutions from IDT.
Using a 25MHz, 18pF parallel resonant crystal, the
following frequencies can be generated based on the 2 frequency
select pins (F_SEL[1:0]): 156.25MHz, 125MHz and 62.5MHz. The
ICS844002-01 uses IDT’s 3^rd generation low phase noise VCO
technology and can achieve <1ps typical rms phase jitter, easily
meeting Ethernet jitter requirements. The ICS844002-01 is
packaged in a small 20-pin TSSOP package.
ICS844002-01
Features
• Two differential LVDS outputs
• Selectable crystal oscillator interface or
single-ended LVCMOS/LVTTL input
• Supports the following output frequencies: 156.25MHz,
125MHz, 62.5MHz
• VCO range: 560MHz – 680MHz
• RMS phase jitter @ 156.25MHz, using a 25MHz crystal
(1.875MHz – 20MHz): 0.41ps (typical)
• Full 3.3V and 2.5V supply modes
• 0°C to 70°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
Block Diagram
F_SEL[1:0] ^Pulldown
2
PLL_SEL ^Pulldown
REF_CLK ^Pulldown
1
25MHz
XTAL_IN
OSC
0
XTAL_OUT
XTAL_SEL ^Pulldown
Phase
Detector
1
VCO
625MHz
(w/25MHz
0
Reference)
M = 25 (fixed)
MR ^Pulldown
F_SEL[1:0]
0 0 ÷4
0 1 ÷5
1 0 ÷10
1 1 not used
Pin Assignment
nc 1
20 VDDO
VDDO 2
19 Q1
Q0
Q0 3 18 Q1
Q0 4 17 GND
Q0
MR 5 16 nc
PLL_SEL 6 15 XTAL_SEL
nc 7
14 REF_CLK
VDDA 8
13 XTAL_IN
Q1
F_SEL0 9 12 XTAL_OUT
VDD 10 11 F_SEL1
Q1
ICS844002-01
20-Lead TSSOP
6.5mm x 4.4mm x 0.925mm
package body
G Package
Top View
IDT™ / ICS™ LVDS FREQUENCY SYNTHESIZER
1
ICS844002AG-01 REV. A SEPTEMBER 28, 2007