ICS9150-08

Features:

· 3.3V outputs: SDRAM, PCI, REF, 48/24MHz
· 2.5V outputs: CPU, IOAPIC
· 20 ohm CPU clock output impedance
· 20 ohm PCI clock output impedance
· Skew from CPU (earlier) to PCI clock - 1 to 4 ns, center 2.6 ns.
· No external load cap for CL=18pF crystals
· ±250 ps CPU, PCI clock skew
· 250ps (cycle to cycle) CPU jitter
· Smooth CPU frequency switching from 50 to 133 MHz
· I2C interface for programming
· 2ms power up clock stable time
· Clock duty cycle 45-55%.
· 56 pin 300 mil SSOP package
· 3.3V operation, 5V tolerant inputs (with series R)
· <5.5ns SDRAM propagation delay from Buffer Input


Pinout




Specifications

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.0 V
Logic Inputs . . . . . . . . . . . . . . . . . . . . . GND -0.5 V to VDD +0.5 V
Ambient Operating Temperature . . . . . . . . . . . . . 0°C to +70°C
Case Temperature . . . . . . . . . . . . . . . . . . . . . . . .. . . .  . . 115°C
Storage Temperature . . . . . . . . . . . . . . . . . . . -65°C to +150°C


Description

The ICS9150-08 generates all clocks required for high speed RISC or CISC microprocessor systems such as Intel PentiumPro or Cyrix. Eight different reference frequency multiplying factors are selectable.

Features include three CPU, seven PCI and seventeen SDRAM clocks. Two reference output of the ICS9150-08 is available equal to the crystal frequency, plus two IOAPIC outputs powered by VDDL1.
One 48 MHz for USB is provided plus a 24 MHz. Spread Spectrum built in at ±0.5% or ±0.25% modulation to reduce EMI. Serial programming I2C interface allows changing functions, stop clock programing and Frequency selection. It is not recommended to use dual function I/O pins to clock slots (ISA, PIC, CPU, DIMM). The add on card may have a pull-up or pull-down. Additionally, the device meets the Pentium power-up stabilization, which requires that CPU and PCI clocks be stable within 2ms after power-up.

High drive PCICLK and SDRAM outputs of the ICS9150-08 typically provide greater than 1 V/ns slew rate into 30pF loads. CPUCLK outputs typically provide better than 1V/ns slew rate into 20pF loads while maintaining 50±5% duty cycle. The REF, 24 and 48 MHz clock outputs typically provide better than 0.5V/ns slew rates into 20pF.