W137

W137 Bx Notebook System Frequency Synthesizer Features Maximized EMI suppression using Cypress’s Spread Spectrum Technology Two copies of CPU output Six copies of PCI output (Synchronous w/CPU output) One 48-MHz output for USB support One selectable 24-/48-MHz output Two Buffered copies of 14.318-MHz input reference signal Supports 100-MHz or 66-MHz CPU operation Power management control input pins Available in 28-pin SSOP (209 mils) SS function can be disabled See W40S11-02 for 2 SDRAM DIMM support PCI_F, PCI1:5 Output to Output Skew:........................ 500 ps PCI_F, PCI1:5 Cycle to Cycle Jitter: ............................ 250 ps CPU to PCI Output Skew: ............... 1.5–4.0 ns (CPU Leads) Output Duty Cycle: .................................................... 45/55% PCI_F, PCI Edge Rate: .............................................. >1 V/ns CPU_STOP#, OE, SPREAD#, SEL48#, PCI_STOP#, PWR_DWN# all have a 250-kΩ pull-up resistor. Table 1. Pin Selectable Frequency SEL100/66# 0/1 0 1 OE 0 1 1 CPU HI-Z 66.6 MHz 100 MHz PCI HI-Z 33.3 33.3 Spread% Don’t Care See Table 2 See Table 2 Key Specifications Supply Voltages: ....................................... VDDQ3 = 3.3V±5% VDDQ2 = 2.5V±5% CPU0:1 Output to Output Skew: ................................ 175 ps CPU0:1 Cycle to Cycle Jitter: ..................................... 200 ps Table 2. Spread Spectrum Feature SPREAD# 0 1 Spread Profile –0.5% (down spread) 0% (spread disabled) Block Diagram X1 ...