CY2272

The CY2272 is a clock synthesizer/driver for a Pentium, Cyrix 6x86, or AMD K6 processor-based mobile PC using Intel®'s 82430TX, Aladdin IV+ or other similar chipsets.

The CY2272-1 outputs four CPU clocks at 2.5V or 3.3V. There are seven PCI clocks, running at one half the CPU clock frequency.

One of the PCI clocks CY2272 is free-running. Another leads the PCI clocks by 14 ns. Additionally, the part outputs six 3.3V SDRAM clocks, one 3.3V USB clock at 48 MHz, one IO clock at 24 MHz, and two high-drive 3.3V reference clocks at 14.318 MHz.

The CY2272 part possesses dedicated power-down, CPU stop, and PCI stop pins for power management control. When the CPU_STOP input is asserted, the CPU clock outputs are driven LOW. When the PCI_STOP input is asserted, the PCI clock outputs (except the free-running PCI clock) are driven LOW.

When the PWR_DWN pin is asserted, the reference oscillator and PLLs are shut down, and all outputs are driven LOW.

The CY2272 outputs are designed for low EMI emissions.

Controlled rise and fall times, unique output driver circuits and factory-EPROM programmable output drive and slew-rate enable optimal configurations for EMI control.