ICS87973I-147 Datasheet, PDF (1/19 Pages) Integrated Circuit Systems – LOW SKEW, 1-TO-12 LVCMOS / LVTTL CLOCK MULTIPLIER/ZERO DELAY BUFFER

LOW SKEW, 1-TO-12 LVCMOS/LVTTL CLOCK MULTIPLIER/
ZERO DELAY BUFFER
ICS87973I-147
General Description
ICS
HiPerClockS™
The ICS87973I-147 is a LVCMOS/LVTTL clock
generator and a member of the HiPerClockS™family
of High Performance Clock Solutions from IDT. The
ICS87973I-147 has three selectable inputs and
provides 14 LVCMOS/LVTTL outputs.
The ICS87973I-147 is a highly flexible device. The three
selectable inputs (1 differential and 2 single ended inputs) are
often used in systems requiring redundant clock sources. Up to
three different output frequencies can be generated among the
three output banks.
The three output banks and feedback output each have their own
output dividers which allows the device to generate a multitude of
different bank frequency ratios and output-to-input frequency
ratios. In addition, 2 outputs in Bank C (QC2, QC3) can be
selected to be inverting or non-inverting. The output frequency
range is 10MHz to 150MHz. The input frequency range is 6MHz to
120MHz.
The ICS87973I-147 also has a QSYNC output which can be used
for system synchronization purposes. It monitors Bank A and
Bank C outputs and goes low one period prior to coincident rising
edges of Bank A and Bank C clocks. QSYNC then goes high again
when the coincident rising edges of Bank A and Bank C occur.
This feature is used primarily in applications where Bank A and
Bank C are running at different frequencies, and is particularly
useful when they are running at non-integer multiples of one
another.
Example Applications:
1.System Clock generator: Use a 16.66MHz reference clock to
generate eight 33.33MHz copies for PCI and four 100MHz
copies for the CPU or PCI-X.
2.Line Card Multiplier: Multiply differential 62.5MHz from a back
plane to single-ended 125MHz for the line Card ASICs and
Gigabit Ethernet Serdes.
3.Zero Delay buffer for Synchronous memory: Fanout up to twelve
100MHz copies from a memory controller reference clock to the
memory chips on a memory module with zero delay.
Features
• Fully integrated PLL
• Fourteen LVCMOS/LVTTL outputs to include: twelve clocks,
one feedback, one sync
• Selectable differential CLK, nCLK inputs or LVCMOS/LVTTL
reference clock inputs
• CLK0, CLK1 can accept the following input levels:
LVCMOS or LVTTL
• CLK, nCLK pair can accept the following differential
input levels: LVPECL, LVDS, LVHSTL, SSTL, HCSL
• Output frequency range: 10MHz to 150MHz
• VCO range: 240MHz to 500MHz
• Output skew: 200ps (maximum)
• Cycle-to-cycle jitter, (all banks ÷4): 55ps (maximum)
• Full 3.3V supply voltage
• -40°C to 85°C ambient operating temperature
• Compatible with PowerPC™and Pentium™Microprocessors
• Available in both standard (RoHS 5) and lead-free (RoHS 6)
packages
Pin Assignment
39 38 37 36 35 34 33 32 31 30 29 28 27
FSEL_B1
FSEL_B0
FSEL_A1
FSEL_A0
QA3
V_DDO
QA2
GNDO
QA1
V_DDO
QA0
GNDO
VCO_SEL
40
41
42
43
44
45
46
47
48
49
50
51
52
1
26
25
24
23
22
21
20
19
18
17
16
15
14
2 3 4 5 6 7 8 9 10 11 12 13
FSEL_FB1
QSYNC
GNDO
QC0
VDDO
QC1
FSEL_C0
FSEL_C1
QC2
V_DDO
QC3
GNDO
INV_CLK
IDT™ / ICS™ LVCMOS CLOCK MULTIPLIER/ZERO DELAY BUFFER
1
ICS87973I-147
52-Lead LQFP
10mm x 10mm x 1.4mm package body
Y Package
Top View
ICS87973DYI-147 REV. A DECEMBER 9, 2008