ICRO
C
LOCK
Description
The MK1705A generates a low EMI output clock
from a clock or crystal input. The part is designed
to dither the LCD interface clock or other clocks
for ATI’s flat panel graphics controllers. The
device uses ICS/MicroClock’s proprietary mixture
of analog and digital Phase-Locked Loop (PLL)
technology to synthesize the frequency, and our
patented technique to spread the frequency
spectrum of the output, thereby reducing the
frequency amplitude peaks by several dB.
The MK1705A is designed to have the output
spread centered around the input frequency. Refer
to the MK1704A for spreading down from the
input frequency, or the MK1714-0x for a crystal
input and the widest selection of spread rates and
multipliers.
We offer many other clocks for computers and
computer peripherals. Consult us when you need
to remove crystals and oscillators from your board.
MK1705A
ATI Low EMI Clock Generator
Features
• Packaged in 8 pin SOIC
• Provides a spread spectrum output clock
• Supports ATI’s flat panel controllers
• Accepts a clock input, provides same frequency
dithered output
• Good for all VGA modes from 40 to 167 MHz
• Peak reduction by 7dB - 14 dB typical on 3rd-
19th odd harmonics
• Low EMI feature can be disabled
• 3.3 V or 5 V ±10% supply voltage
• Advanced, low power CMOS process
Block Diagram
VDD GND
S0
S1
Low EMI Enable
Power Down
Input
Buffer
PLL Clock
Synthesis and
Spread Spectrum
Circuitry
Output
Buffer
Clock Out
Input Clock
MDS 1705A B
1
Revision 8090
Printed 8/9/00
Integrated Circuit Systems, Inc. •525 Race Street•San Jose•CA • 95126 • (408)295-9800tel • www.icst.com
ICS [ INTEGRATED CIRCUIT SYSTEMS ]
