MK3235 Datasheet, PDF (1/4 Pages) Integrated Circuit Systems – Handheld System Clock Synthesizer

I CR O C LOC K
Description
The MK3235 is the smallest size, lowest power system
clock synthesizer available. It is the ideal way to
generate clocks for handheld computers, such as PDAs,
PICs, and other devices where low power is required.
Using analog Phase-Locked Loop (PLL) techniques,
the device operates from a single 32.768 kHz crystal to
produce the 32.768kHz, 14.318MHz, and serial
communications output clocks.
The device has three power down modes for the
14.3MHz, communications, and 32.768kHz clocks.
The MK3235 can save board space and cost even if it
only replaces the 32kHz oscillator circuitry and one
additional surface mount crystal or oscillator. The
extremely low IDD, the ease of surface mounting, and
the power down capability are added benefits in using
the part.
MK3235
Handheld System Clock Synthesizer
Features
• Input crystal frequency of 32.768 kHz
• Lowest power solution available
• Lowest profile clock solution where height is critical
• Three output clocks
• 3.3V or 5.0V operation
• Duty cycle of 45/55
• 14.3MHz or 14.3MHz+Comm clock power downs
• Separate battery supply pin for 32 kHz runs to 2V
• IDD less than 4µA when 32 kHz running
• Packaged in 16 pin narrow SOIC
Block Diagram
VDD GND
PD14
14.318MHz
Clock Synthesis
and Control
Circuitry
Output
Buffer
14.3 MHz
PDCOMM
PD
VDD32
32.768 kHz
crystal _X1
X2
Crystal
Oscillator
Communications
Clock Synthesis
and Control
Circuitry
Output
Buffer
1.843 or
3.686 MHz
Output
Buffer
32.768 kHz
MDS 3235 D
1
Revision 092397
Printed 11/16/00
Integrated Circuit Systems, Inc.•525 Race Street•San Jose•CA•95126•[phone]tel•www.icst.com