General Description

The ICS9178-03 generates all clocks required for high speed PowerPC RISC microprocessor systems. Generating clocks in phase with an external reference frequency allows the ICS9178-03 to be used as a multiplying zero delay buffer. Three different multiplying factors are externally selectable. These factors can be customized for specific applications. An external frequency can be directly applied to aid system testing. With 2X processor clock speeds up to 245 MHz, PECL outputs are provided. User selectable frequency ratios are available for PCLK/BCLK and PCLK/XCLK. Each pair of clocks outputs have separate supply pins to minimize output jitter and allow them to operate at 5V, 3.3V or custom voltage levels.

特性 Features

? Generates 2 PECL 2x processor, 2 TTL/CMOS 1x processor and 10 selectable bus clocks

? 2XPCLK ranges from 75 MHz to 245 MHz (5V or 5V/3.3V mixed supply) or 60 to 170 MHz (3.3V only)

? Asymmetric duty cycle bus clock for PowerPC

? Bus to processor clock skews less than –250ps

? 2XPCLK to PCLK skew controlled at 300 –300ps

? Selectable reference multiplying factors

? Selectable PCLK/BCLK and PCLK/XCLK ratios

? Separate supplies allow 5V and 3.3V output mix

? 3.0V - 5.5V supply range

? 44-pin PQFP package

Applications

? Ideal for high-speed systems based on PowerPC