ICS557GI-03T

Overview

The ICS557GI-03T is a spread spectrum clock generator designed for PCI Express Gen 1 and Ethernet applications. It operates with a 25 MHz input to produce two differential HCSL outputs at selectable frequencies of 25, 100, 125, or 200 MHz. The device supports LVDS levels via alternative termination. Key electrical parameters include a supply voltage range of 2.97 V to 3.63 V, cycle-to-cycle jitter of 80 ps maximum, and an operating temperature range of -40°C to +85°C. It utilizes a patented PLL technique and features spread spectrum capability configured via select pins.

Feature Summary

• Supports PCI Express Gen 1 and Ethernet requirements with spread spectrum clock generation.
• Provides two differential HCSL outputs (25 MHz to 200 MHz) or LVDS compatible levels.
• Configurable output frequency and spread type/amount via S0, S1, SS0, and SS1 pins.
• Operates on a single 3.3 V supply with industrial temperature rating (-40°C to +85°C).

Applications

• PCI Express Gen 1 clock source in PC or embedded systems.
• Ethernet system clock distribution.
• Applications requiring substantial electromagnetic interference (EMI) reduction.

Procurement Notes

Verify the 'I' suffix confirms the industrial temperature range (-40°C to +85°C). Confirm the 'T' suffix indicates Tape and Reel packaging. Ensure RoHS compliance requirements are met by checking for the 'LF' designation if lead-free status is mandatory for the specific assembly process.

Selection Notes

Select this component when a 25 MHz crystal input is available and differential HCSL outputs are required for PCIe Gen 1. Choose based on the necessary output frequency (25, 100, 125, or 200 MHz) and spread spectrum percentage (-0.5% or -0.75%). Ensure the PCB layout accommodates the 16-TSSOP package dimensions and provides adequate decoupling near VDD pins.

Part Context

This part belongs to the ICS557-03 series of PCI Express Gen 1 clock sources. The 'G' denotes the 16-pin TSSOP package. The 'I' specifies the industrial temperature grade. The 'LF' suffix indicates lead-free/RoHS compliance. The 'T' suffix designates tape and reel shipping packaging. It is functionally equivalent to other variants in the series differing only in temperature range, packaging, or compliance.

Replacement Considerations

Public confirmed substitutes include ICS557GI-03LFT (Lead-Free, Tape & Reel) and ICS557GI-03 (Tube packaging). For commercial temperature range applications, the ICS557G-03T variant is available. Ensure pin compatibility and thermal characteristics match the existing design when substituting.

FAQ

How is the output frequency selected?

The output frequency is selected using the S0 and S1 input pins. Logic levels determine the frequency: 00 for 25 MHz, 01 for 100 MHz, 10 for 125 MHz, and 11 for 200 MHz.

What is the maximum cycle-to-cycle jitter?

The maximum cycle-to-cycle jitter is guaranteed to be 80 ps under standard operating conditions (VDD = 3.3 V ±10%, -40°C to +85°C).

Can the device support LVDS output levels?

Yes, the device can be configured for LVDS compatible voltage levels by using an alternative termination scheme as described in the datasheet's LVDS Compatible Layout Guidelines.