ICS843034-01 Datasheet, PDF (1/22 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ MULTI-RATE LVPECL FREQUENCY SYNTHESIZER

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS843034-01
FEMTOCLOCKS™
MULTI-RATE LVPECL FREQUENCY SYNTHESIZER
GENERAL DESCRIPTION
The ICS843034-01 is a general purpose, low
ICS
phase noise LVPECL synthesizer which can
HiPerClockS™ generate frequencies for a wide variety of
applications. The ICS843034-01 has a 4:1
input Multiplexer from which the following
inputs can be selected: 1 differential input, 1
single-ended input, or one of two crystal oscillators,
thus making the device ideal for frequency translation or
generation. Each differential LVPECL output pair has an
output divider which can be independently set so that two
different frequencies can be generated. Additionally, each
LVPECL output pair has a dedicated power supply pin so
the outputs can run at 3.3V or 2.5V. The ICS843034-01
also supplies a buffered copy of the reference clock or
crystal frequency on the single-ended REF_CLK pin which
can be enabled or disabled (disabled by default). The output
frequency can be programmed using either a serial or
parallel programming interface.
The ICS843034-01 has excellent <1ps phase jitter
performance over the 637kHz - 5MHz integration range, thus
making it suitable for use in Fibre Channel, SONET, and
Ethernet/1Gb Ethernet applications.
Example applications include systems which must support
both FEC and non FEC rates. In 10Gb Fibre Channel, for
example, you can use a 25.5MHz crystal to generate a
159.375MHz reference clock, and then switch to a
20.544MHz crystal to generate 164.355MHz for 66/64 FEC.
Other applications could include supporting both Ethernet
frequencies and SONET frequencies in an application. When
Ethernet frequencies are needed, a 25MHz crystal can be
used and when SONET frequencies are needed, the input
MUX can be switched to select a 38.88MHz Crystal.
PIN ASSIGNMENT
FEATURES
• Dual differential 3.3V LVPECL outputs which can be set
independently for either 3.3V or 2.5V
• 4:1 Input Mux:
1 differential input
1 single-ended input
2 crystal oscillator interfaces
• CLK, nCLK pair can accept the following differential
input levels: LVPECL, LVDS, LVHSTL, HCSL, SSTL
• TEST_CLK accepts LVCMOS or LVTTL input levels
• Output frequency range: 30.625MHz to 640MHz
• Crystal input frequency range: 12MHz to 40MHz
• VCO range: 490MHz to 640MHz
• Parallel or serial interface for programming feedback divider
and output dividers
• RMS phase jitter at 106.25MHz, using a 25.5MHz crystal
(637kHz to 5MHz): 0.61ps (typical)
• Supply voltage modes:
LVPECL outputs (core/outputs):
3.3V/3.3V
3.3V/2.5V
REF_CLK output (core/outputs):
3.3V/3.3V
3.3V/2.5V
• 0°C to 70°C ambient operating temperature
• Available in both standard and lead-free RoHS-compliant
packages
M8
NB0
NB1
NB2
OE_REF
OE_A
OE_B
VCC
NA0
NA1
NA2
VEE
48 47 46 45 44 43 42 41 40 39 38 37
1
36
2
35
3
34
4 ICS843034-01 33
5
48-Pin LQFP
32
6 _{7mm x 7mm x 1.4mm} 31
7
package body
30
8
Y Package
29
9
Top View
28
10
27
11
26
12
25
13 14 15 16 17 18 19 20 21 22 23 24
XTAL_OUT1
XTAL_IN1
XTAL_OUT0
XTAL_IN0
TEST_CLK
SEL1
SEL0
VCCA
S_LOAD
S_DATA
S_CLOCK
MR
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.
843034AY-01
www.icst.com/products/hiperclocks.html
REV. C NOVEMBER 28, 2005
1