PI6C557-03ALE

Overview

The PI6C557-03ALE is a spread spectrum clock generator compliant with PCI Express 2.0 and Ethernet requirements, manufactured by Diodes Incorporated. It features an integrated Phase-Locked Loop (PLL) that accepts a 25MHz crystal or clock input to generate two differential outputs in HCSL or LVDS formats. The device supports output frequencies of 25MHz, 100MHz, 125MHz, and 200MHz, selectable via external pins. It provides configurable spread spectrum modulation options of -0.5%, -0.75%, or no spread to reduce electromagnetic interference. Operating on a 3V to 3.6V supply, it is housed in a 16-TSSOP package.

Feature Summary

• PCIe 2.0 Compliant: Designed for PC and embedded systems to substantially reduce EMI through spread spectrum generation.
• Dual Differential Outputs: Provides two pairs of differential outputs compatible with HCSL (0.8V current mode) or LVDS standards.
• Configurable Frequency & Spread: Supports 25MHz, 100MHz, 125MHz, and 200MHz outputs; allows selection of -0.5%, -0.75%, or no spread via external pins.
• Low Jitter Performance: Achieves typical phase jitter of 2.1ps RMS and cycle-to-cycle jitter of 35ps.

Applications

• PCI Express 2.0 Clock Generation
• Ethernet System Timing
• PC Motherboard Clock Distribution
• Embedded Systems EMI Reduction

Procurement Notes

Verify the 'E' suffix indicates Pb-free and Green packaging compliant with RoHS directives. Confirm the 'X' suffix availability if tape-and-reel packaging is required, as the base model implies tube packaging. Ensure the specific ordering code matches the required package type (TSSOP vs QSOP) and check for any Product Change Notifications regarding pinout or electrical parameter updates.

Selection Notes

Select this component when designing for PCIe 2.0 compliance requiring spread spectrum capabilities. Choose between HCSL and LVDS output configurations based on the load requirements of the destination devices. Ensure the system design accommodates the 25MHz crystal input and includes appropriate decoupling capacitors near VDD pins. Verify that the external pull-up/pull-down resistors on control pins (S0, S1, SS0, SS1) are correctly configured to set the desired frequency and spread percentage.

Part Context

This part belongs to the PI6C557 series of clock generators from Diodes Incorporated. The '03A' designation identifies the specific variant supporting PCIe 2.0 with dual differential outputs. The 'ALE' suffix specifies the 16-pin TSSOP package, lead-free composition, and green material status. Other variants in the family may offer different packages like QSOP or support different interface standards.

Replacement Considerations

Direct replacements within the same family include the PI6C557-03AQEX for QSOP packaging. For applications requiring different output types or frequencies, consult the broader PI6C557 product line datasheet for compatible alternatives such as single-output variants or those supporting higher PCIe generations.