P R E L I M I N A RY I N F O R M AT I O N
ICS1493-17
Clock Synthesizer for Portable Systems
Description
The ICS1493-17 is a low-power, low-jitter clock
synthesizer designed to replace multiple crystals and
oscillators in portable audio/video systems. The device
generates a 37 MHz processor clock, a 48 MHz USB
clock, a fixed 22.5792 MHz audio clock, a selectable
24.576 MHz or 22.5792 MHz audio clock, and a 27MHz
reference clock for video. Using ICS’ proprietary mix of
analog and digital Phase-Locked Loop (PLL)
technology, the device spreads the frequency spectrum
of the 37 MHz output, reducing the peak amplitude of
by up to 16 dB. An output enable (OE) pin lowers the
chip power consumption while tri-stating all outputs.
Features
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Extremely low operating current (11 mA)
Packaged in 20-pin QFN (Pb-free)
Input crystal or clock frequency of 27 MHz
Output reference frequency of 27 MHz
Fixed output frequencies of 37 MHz, 48 MHz and
22.5792 MHz
Selectable output frequency of either 22.5792 MHz
or 24.576 MHz
Configurable spread spectrum on 37 MHz output
Operating core voltage of 1.8 V
Output voltage of 1.8 V or 2.5 V
Advanced, low-power CMOS process
Block Diagram
VDD
3
PLL1
(Spread)
VDDO
2
OE
37M
SCK
SDATA
IIC
Control
Logic
PLL2
48M
PLL3
22/24M
PLL4
27 MHz
clock or
crystal input
X1
Crystal
Oscillator/
Clock
Buffer
5
GND
22M
27M
X2
Optional tuning
capacitors
MDS 1493-17 A
Integrated Circuit Systems
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1
5 25 Race Street, San Jo se, CA 9 512 6
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Revision 101005
tel (40 8) 2 97-12 01
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w w w. i c st . c o m
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
