Skip to main content


Frequency Generator & Integrated Buffers for PENTIUM/ProTM

The IDT9248-39 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.


  • 3.3V outputs: SDRAM, PCI, REF, 48/24MHz
  • 2.5V outputs: CPUIOAPIC
  • 20 ohm CPU clock output impedance
  • 20 ohm PCI clock output impedance
  • Skew from CPU (earlier) to PCI clock - 1.5 to 4 ns, center 2.6 ns.
  • No external load cap for CL=18pF crystals
  • ±175 ps CPU clock skew
  • 250ps (cycle to cycle) CPU jitter
  • Smooth frequency switch, with selections from 66.8 to 150 MHz CPU.
  • I2C interface for programming
  • 3ms power up clock stable time
  • Clock duty cycle 45-55%.
  • 48 pin 300 mil SSOP package
  • 3.3V operation, 5V tolerant inputs (with series R)
  • <5ns propagation delay SDRAM from Buffer Input

Product Specification

Chipset ManufacturerChipset NameClock Spec.Core Voltage (V)Input Freq (MHz)Outputs (#)Platform NamePower Consumption Typ (mW)Spread SpectrumXtal Freq (kHz)

Product Options

Orderable Part IDPart StatusPkg. CodePkg. TypeLead Count (#)Temp. GradePb (Lead) FreeCarrier TypeSample & Buy
9248DF-39LFActivePVG48SSOP48CYesTubeCheck Availability
9248DF-39LFTActivePVG48SSOP48CYesReelCheck Availability


Technical Documentation

Title Type Format File Size Datesort icon
Datasheets & Errata
9248-39 Datasheet Datasheet PDF 287 KB Mar 23, 2006
PCN# : A1506-02 Gold wire to Copper wire Product Change Notice PDF 35 KB Oct 8, 2015
PCN# : A1504-04 Assembly Transfer from Amkor Philippines to OSE Taiwan Product Change Notice PDF 484 KB Jul 2, 2015
PCN# : TB1303-02 Change of Tape & Reel Packing Method for Selective Products Product Change Notice PDF 361 KB Mar 24, 2013

Software & Tools

Title Type Format File Size Datesort icon
9248-39 IBIS Model Model - IBIS ZIP 31 KB Mar 23, 2006