ICS8421004I-01 Datasheet, PDF (1/13 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO-HSTL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS8421004I-01
FEMTOCLOCKS™ CRYSTAL-TO-
HSTL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS8421004I-01 is a 4 output HSTL
ICS
Synthesizer optimized to generate Ethernet
HiPerClockS™ _{reference clock frequencies and is a member of}
the HiPerClocks^TM family of high performance
clock solutions from ICS. 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 ICS8421004I-01
uses ICS’ 3^rd generation low phase noise VCO technology
and can achieve 1ps or lower typical rms phase jitter, easily
meeting Ethernet jitter requirements. The ICS8421004I-01 is
packaged in a small 24-pin TSSOP package.
FEATURES
• Four HSTL outputs (VOHmax = 1.4V)
• Selectable crystal oscillator interface or
LVCMOS/LVTTL single-ended 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): 0.44ps (typical)
• Power supply modes:
Core/Output
3.3V/1.8V
2.5V/1.8V
• -40°C to 85°C ambient operating temperature
FREQUENCY SELECT FUNCTION TABLE
F_SEL1
0
0
1
1
F_SEL0
0
1
0
1
M Divider
Value
25
25
25
25
N Divider
M/N
Value Divider Value
4
6.25
5
5
10
2.5
not used
Output
Frequency
(25MHz Ref.)
156.25
125
62.5
not used
BLOCK DIAGRAM
F_SEL[1:0] ^Pulldown
nPLL_SEL ^Pulldown
TEST_CLK ^Pulldown
1
25MHz
XTAL_IN
OSC
0
XTAL_OUT
nXTAL_SEL ^Pulldown
2
Phase
Detector
F_SEL[1:0]
0 0 ÷4
1
0 1 ÷5
1 0 ÷10
VCO
1 1 Not Used
0
M = 25 (fixed)
MR ^Pulldown
PIN ASSIGNMENT
nQ1 1
Q1 2
VDDO 3
Q0 4
nQ0 ⁵
MR ⁶
nPLL_SEL ⁷
nc ⁸
VDDA ⁹
F_SEL0 ¹⁰
VDD ¹¹
F_SEL1 ¹²
24 nQ2
23 Q2
2 2 VDDO
21 Q3
20 nQ3
19 GND
18 VDD
17 nXTAL_SEL
16 _{TEST_CLK}
15 _GND
14 _{XTAL_IN}
13 _{XTAL_OUT}
ICS8421004I-01
24-Lead TSSOP
4.40mm x 7.8mm x 0.92mm
package body
G Package
Q0
Top View
nQ0
Q1
nQ1
Q2
nQ2
Q3
nQ3
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.
8421004AGI-01
www.icst.com/products/hiperclocks.html
REV. A MACH 29, 2005
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