ICS9248-39

Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Logic Inputs . . . . . . . . . . . . .  GND 0.5 V to V_DD +0.5 V
Ambient Operating Temperature . . . . . .  0°C to +70°C
Case Temperature . . . . . . . . . . . . . . . . . . . . . . . .115°C
Storage Temperature . . . . . . . . . . . .65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only and functional operation of the device at these or any other conditions above those listed in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability.

The ICS9248-39 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 externally selectable with smooth frequency transitions.

Features of the ICS9248-39 include two CPU, six PCI and thirteen SDRAM clocks. Two reference outputs are available equal to the crystal frequency. Plus the IOAPIC output powered by VDDL1. One 48 MHz for USB, and one 24 MHz clock for Super IO. Spread Spectrum built in at ±0.5% or ±0.25% modulation to reduce the EMI. Serial programming I2C interface allows changing functions, stop clock programing and Frequency selection.

Additionally, the device meets the Pentium power-up stabilization, which requires that CPU and PCI clocks be stable within 2ms after power-up. It is not recommended to use I/O dual function pin for the slots (ISA, PIC, CPU, DIMM). The add on card might have a pull up or pull down. High drive PCICLK and SDRAM outputs 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 and 24 and 48 MHz clock outputs of the ICS9248-39 typically provide better than 0.5V/ns slew rates into 20pF.