ICS844002 Datasheet, PDF (1/16 Pages) Integrated Device Technology – FEMTOCLOCKS™ CRYSTAL-TO-LVDS FREQUENCY SYNTHESIZER

FEMTOCLOCKS™ CRYSTAL-TO-LVDS
FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS844002 is a 2 output LVDS Synthesizer
ICS
optimized to generate Fibre Channel reference
HiPerClockS™ _{c l o ck f r e q u e n c i e s a n d i s a m e m b e r o f t h e}
HiPerClocks^TM family of high performance clock
solutions from IDT. Using a 26.5625MHz 18pF
parallel resonant crystal, the following frequencies can be
generated based on the 2 frequency select pins (F_SEL[1:0]):
212.5MHz, 187.5MHz, 159.375MHz, 106.25MHz and
53.125MHz. The ICS844002 uses IDT’s 3^rd generation low
phase noise VCO technology and can achieve <1ps typical rms
phase jitter, easily meeting Fibre Channel jitter requirements.
The ICS844002 is packaged in a small 20-pin TSSOP package.
ICS844002
FEATURES
• Two LVDS outputs
• Selectable crystal oscillator interface
or LVCMOS/LVTTL single-ended input
• Supports the following output frequencies: 212.5MHz,
187.5MHz, 159.375MHz, 106.25MHz and 53.125MHz
• VCO range: 560MHz - 680MHz
• RMS phase jitter @ 212.5MHz, using a 26.5625MHz crystal
(637kHz - 10MHz): 0.65ps (typical)
• Full 3.3V or 2.5V supply modes
• 0°C to 70°C ambient operating temperature
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
FREQUENCY SELECT FUNCTION TABLE
Input
Frequency
(MHz)
26.5625
F_SEL1
Inputs
F_SEL0
M Divider
Value
N Divider
Value
M/N Divider
Value
Output
Frequency
(MHz)
0
0
24
3
8
212.5
26.5625
0
1
24
4
6
159.375
26.5625
1
0
24
6
4
106.25
26.5625
1
1
24
12
2
53.125
23.4375
0
0
24
3
8
187.5
BLOCK DIAGRAM
F_SEL[1:0] ^Pulldown
nPLL_SEL ^Pulldown
REF_CLK ^Pulldown
1
26.5625MHz
XTAL_IN
OSC
0
XTAL_OUT
nXTAL_SEL ^Pulldown
2
Phase
Detector
1
VCO
637.5MHz
0
(w/26.5625MHz
Reference)
M = 24 (fixed)
MR ^Pulldown
F_SEL[1:0]
0 0 ÷3
0 1 ÷4
1 0 ÷6
1 1 ÷12
PIN ASSIGNMENT
nc ₁
VDDO ₂
Q0 ₃
nQ0 4
MR 5
nPLL_SEL 6
nc 7
VDDA 8
F_SEL0 9
VDD 10
20 ^VDDO
19 Q1
18 ^nQ1
17 ^GND
16 nc
15 ^nXTAL_SEL
14 ^REF_CLK
13 XTAL_IN
12 ^XTAL_OUT
11 ^F_SEL1
ICS844002
20-Lead TSSOP
6.5mm x 4.4mm x 0.92mm
package body
G Package
Top View
Q0
nQ0
Q1
nQ1
IDT^™ / ICS^™ LVDS FREQUENCY SYNTHESIZER
1
ICS844002AG REV. A SEPTEMBER 28, 2007