Multiple Output Clock Synthesizer

The MPC9108 is a multiple CMOS output clock synthesizer targeted for disk drive applications. The device interfaces to a 20MHz crystal as its frequency source. From this source the device provides a buffered copy of the 20MHz clock as well as synthesized 40MHz and 50MHz output clocks.

• Fully Integrated PLL

• Fully Integrated Crystal Oscillator

• Low cost, low jitter design

• Low cost 8–lead SOIC packaging

In addition to the output clock frequencies, the MPC9108 also offers a lock indicator output. When the internal PLL achieves phase and frequency lock the CLK_LOCK signal will go HIGH. The pin will remain HIGH unless the PLL loses lock due to input clock or power supply disturbances.

The XTALIN pin (pin 1) can be over–driven with a standard 5V CMOS signal. When an externally generated reference is used the XTALOUT pin should be left open.

The MPC9108 operates from a 5.0V supply across the commercial temperature range of 0°C to 70°C. The 8–lead SOIC package is used to optimize board space efficiency as well as minimizing cost.