ICS557GI-03

Overview

The ICS557GI-03 is a spread spectrum clock generator designed for PCI Express Gen 1 and Ethernet applications. It utilizes a Phase-Locked Loop (PLL) to generate differential outputs from a 25 MHz crystal or clock input. The device provides two pairs of HCSL outputs at frequencies up to 200 MHz, or LVDS outputs up to 100 MHz. Key electrical parameters include a supply voltage range of 2.97 V to 3.63 V, an operating temperature range of -40°C to +85°C, and cycle-to-cycle jitter of 80 ps maximum. It is packaged in a 16-pin TSSOP.

Feature Summary

• Supports HCSL (up to 200 MHz) and LVDS (up to 100 MHz) output levels
• Spread spectrum capability with configurable down-spread amounts (-0.5% or -0.75%) via select pins
• Low cycle-to-cycle jitter of 80 ps maximum
• Industrial temperature range (-40°C to +85°C)

Applications

• PCI Express Gen 1 systems
• Ethernet infrastructure
• PC and embedded systems requiring EMI reduction

Procurement Notes

Verify the specific ordering suffix against the manufacturer's datasheet to confirm package type and temperature rating. Suffixes such as 'LF' indicate lead-free compliance, while 'T' denotes tape and reel packaging. Confirm that the selected variant matches the required industrial temperature range and RoHS status for the intended application environment.

Selection Notes

Select the ICS557GI-03 when PCI Express Gen 1 compliance and EMI reduction are required. Ensure the design supports the necessary external components, including a 25 MHz parallel resonant crystal with less than 300 ppm error and appropriate termination resistors for HCSL or LVDS signaling. Verify that the 1:2 output ratio meets the system clock distribution needs.

Part Context

This component belongs to the 557-03 series of clock generators originally manufactured by Integrated Device Technology (IDT), which has since been acquired by Renesas Electronics. The 'I' suffix specifically designates the industrial temperature grade variant within this family.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Designers should consult current Renesas or SiTime timing product catalogs for equivalent PCIe clock sources following the IDT acquisition transition.

FAQ

How is the spread spectrum amount configured?

The spread type and amount are configured via the SS0 and SS1 select pins. Options include no spread, down-spread of -0.5%, or down-spread of -0.75%.

What is the maximum output frequency for HCSL mode?

The maximum output frequency for HCSL mode is 200 MHz.

Does the device support single-ended clock inputs?

Yes, the X1/ICLK pin accepts either a 25 MHz fundamental mode parallel resonant crystal or a single-ended clock signal.