ICS844020-45 Datasheet, PDF (1/13 Pages) Integrated Device Technology – FEMTOCLOCK™ CRYSTAL-TO-LVDS/LVCMOS FREQUENCY SYNTHESIZER

PRELIMINARY
FEMTOCLOCK™ CRYSTAL-TO-LVDS/
LVCMOS FREQUENCY SYNTHESIZER
ICS844020-45
GENERAL DESCRIPTION
ICS
The ICS844020-45 is a 20 output synthesizer
HiPerClockS™ ^{optimized to generate Gigabit and 10 Gigabit}
Ethernet clocks and is a member of the
HiPerClockS™ family of high performance clock
solutions from ICS. Using a 25MHz 18pF parallel
resonant crystal, the device will generate 156.25, 125MHz,
25MHz and 3.90625MHz clocks with mixed LVDS and LVTTL
output logic. The ICS844020-45 uses ICS’ 3rd generation low
phase noise VCO technology and can achieve <1ps typical rms
phase jitter, easily meeting Ethernet jitter requirements. The
ICS844020-45 is packaged in a 64-pin TQFP package with
exposed pad for optimum thermal performance.
FEATURES
• Sixteen differential LVDS outputs at 125MHz
One differential LVDS output at 156.25MHz
One LVCMOS/LVTTL single-ended output at 125MHz
One LVCMOS/LVTTL single-ended output at 25MHz
One LVCMOS/LVTTL single-ended output at 3.90625MHz
• Crystal oscillator interface
• VCO range: 490MHz - 680MHz
• RMS phase jitter @ 125MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.4ps (typical)
• RMS phase jitter @ 156.25MHz, using a 25MHz crystal
(1.875MHz - 20MHz): 0.37ps (typical)
PIN ASSIGNMENT
• Full 2.5V operating supply
• 0°C to 70°C ambient operating temperature
• Available in both standard and lead-free RoHS-compliant
packages
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
GND 1
48 GND
Q0 ²
47 nQ14
nQ0 3
46 Q14
VDD ⁴
45 VDD
Q1 5
nQ1 6
ICS844020-45
44 nQ13
43 Q13
GND 7
Q2 ⁸
nQ2 9
VDD 10
Q3 ¹¹
nQ3 12
64-Lead TQFP, EPAD
10mm x 10mm x 1.0mm
package body
Y package
Top View
42 GND
41 nQ12
40 Q12
39 VDD
38 nQ11
37 Q11
GND 13
36 GND
Q4 ¹⁴
35 ^nQ10
nQ4 15
34 Q10
VDD 16
33 VDD
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
BLOCK DIAGRAM
XTAL_IN
XTAL_OUT
25MHz
OSC
Phase
Detector
VCO
490-680MHz
÷25
÷5
÷4
÷160
125MHz
Q0
nQ0
Q15
nQ15
Q17
156.25MHz
nQ16
Q16
3.90625MHz
Q18
25MHz
Q19
The Preliminary Information presented herein represents a product in prototyping or pre-production. The noted characteristics are based on initial product
characterization. Integrated Circuit Systems, Incorporated (ICS) reserves the right to change any circuitry or specifications without notice.
IDT^™ / ICS^™ LVDS/LVCMOS FREQUENCY SYNTHESIZER
1
ICS844020-45 REV A JUNE 14, 2006