PI6C557-03LEX

Overview

The PI6C557-03LEX is a spread spectrum clock generator designed for PCI Express and Ethernet applications. It utilizes a Phase-Locked Loop (PLL) to generate two differential HCSL outputs from a 25MHz crystal or clock input. The device supports output frequencies of 25, 100, 125, and 200MHz with selectable spread spectrum modulation of ±0.25%, -0.5%, or -0.75%. Operating on a 3V to 3.6V supply, it features LVDS-compatible outputs and operates within an industrial temperature range of -40°C to +85°C in a 16-TSSOP package.

Feature Summary

• Generates two differential HCSL outputs at 25, 100, 125, or 200MHz
• Supports spread spectrum modulation: Center ±0.25%, Down -0.5%, Down -0.75%, or No Spread
• LVDS compatible voltage levels with typical cycle-to-cycle jitter of 60ps
• Industrial temperature range (-40°C to +85°C) and RoHS compliant

Applications

• PCI Express clock generation
• Ethernet system timing
• PC and embedded systems EMI reduction

Procurement Notes

Verify the 'LEX' suffix indicates the 16-TSSOP package and Tape/Reel packaging format. Confirm that the specific revision level matches the design requirements, as Diodes Incorporated reserves the right to modify products without notice. Ensure compatibility with the required spread spectrum settings via the SS0 and SS1 pins.

Selection Notes

Select this component when dual differential HCSL outputs are required for PCIe or Ethernet interfaces. The device requires a 25MHz fundamental mode parallel resonant crystal with less than 300PPM error. External termination resistors (RS and RT) must be added to meet impedance requirements, typically 33Ω series and 49.9Ω to ground for standard HCSL routing.

Part Context

This part belongs to the PI6C557 family of clock generators from Diodes Incorporated. The base model PI6C557-03 provides the core functionality, while the 'LE' suffix denotes lead-free and green packaging, and 'X' specifies tape and reel delivery. Other variants in the family may offer different packages or automotive qualifications.

Replacement Considerations

Direct replacements include other PI6C557 variants such as PI6C557-03BQE or PI6C557-03BLE, though these may differ in package type (QSOP vs TSSOP) or packaging format (Tube vs Reel). Verify pinout and electrical characteristics before substitution.