Overview
Description
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.
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 - 1.5 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
Comparison
Applications
Documentation
Featured Documentation
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| Type | Title | Date |
| Datasheet | PDF 324 KB | |
| End Of Life Notice | PDF 606 KB | |
| End Of Life Notice | PDF 599 KB | |
| Product Change Notice | PDF 35 KB | |
| Product Change Notice | PDF 484 KB | |
| Product Change Notice | PDF 361 KB | |
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Design & Development
Models
ECAD Models
Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on products in the Product Options table. If a symbol or model isn't available, it can be requested directly from the website.
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