ICS873990 Datasheet, PDF (1/16 Pages) Integrated Circuit Systems – LOW VOLTAGE, LVCMOS/ CRYSTAL-TO-LVPECL/ECL CLOCK GENERATOR

Integrated
Circuit
Systems, Inc.
ICS873990
LOW VOLTAGE, LVCMOS/
CRYSTAL-TO-LVPECL/ECL CLOCK GENERATOR
GENERAL DESCRIPTION
The ICS873990 is a low voltage, low skew, 3.3V
ICS
LVPECL/ECL Clock Generator and a member
HiPerClockS™ _{of the HiPerClockS™ family of High Performance}
Clock Solutions from ICS. The ICS873990 has
two selectable clock inputs. The XTAL1 and
XTAL2 are used to interface to a crystal and the TEST_CLK
pin can accept a LVCMOS or LVTTL input. This device has a
fully integrated PLL along with frequency configurable out-
puts. An external feedback input and output regenerates
clocks with “zero delay”.
The four independent banks of outputs each have their own
output dividers, which allow the device to generate a multi-
tude of different bank frequency ratios and output-to-input
frequency ratios. The output frequency range is 25MHz to
400MHz and the input frequency range is 6.25MHz to
125MHz. The PLL_SEL input can be used to bypass the PLL
for test and system debug purposes. In bypass mode, the
input clock is routed around the PLL and into the internal out-
put dividers.
The ICS873990 also has a SYNC output which can be used
for system synchronization purposes. It monitors Bank A and
Bank C outputs for coincident rising edges and signals a pulse
per the timing diagrams in this data sheet. This feature is used
primarily in applications where Bank A and Bank C are run-
ning at different frequencies, and is particularly useful when
they are running at non-integer multiples of each other.
FEATURES
• 14 differential LVPECL outputs
• Selectable crystal oscillator interface or TEST_CLK inputs
• TEST_CLK accepts the following input levels:
LVCMOS, LVTTL
• Output frequency: 400MHz (maximum)
• Crystal input frequency range: 10MHz to 25MHz
• VCO range: 200MHz to 800MHz
• Output skew: 250ps (maximum)
• Cycle-to-cyle jitter: ±50ps (typical)
• LVPECL mode operating voltage supply range:
V = 3.135V to 3.465V, V = 0V
CC
EE
• ECL mode operating voltage supply range:
V = 0V, V = -3.465V to -3.135V
CC
EE
• 0°C to 70°C ambient operating temperature
• Industrial temperature available upon request
• Lead-Free package fully RoHS compliant
PIN ASSIGNMENT
Example Applications:
1. Line Card Multiplier: Multiply 19.44MHz from a back-plane
to 77.76MHz on the line card ASIC and Serdes.
2. Zero Delay Buffer: Fan out up to thirteen 100MHz copies
from a reference clock to multiple processing units on an
embedded system.
nQB3
QB3
VCCO
nQA0
QA0
nQA1
QA1
nQA2
QA2
nQA3
QA3
SYNC_SEL
VCO_SEL
39 38 37 36 35 34 33 32 31 30 29 28 27
40
26
41
25
42
24
43
23
44
22
45
21
46
ICS873990
20
47
19
48
18
49
17
50
16
51
15
52
14
1 2 3 4 5 6 7 8 9 10 11 12 13
QC1
nQC1
QC0
nQC0
VCCO
QD1
nQD1
QD0
nQD0
VCCO
QFB
nQFB
VCCA
873990AY
52-Lead LQFP
10mm x 10mm x 1.4mm package body
Y package
Top View
www.icst.com/products/hiperclocks.html
1
REV. B JUNE 13, 2005