841402DKILFT

Specialized ICS Overview

The ICS841402DKI is a FemtoClock crystal-to-0.7V differential HCSL clock generator designed for PCIe and sRIO applications. It utilizes a 25MHz parallel resonant crystal to generate 100MHz, 125MHz, 200MHz, or 400MHz clock signals. The device features two 0.7V differential HCSL outputs and one LVCMOS/LVTTL reference clock output. It supports configurable spread-spectrum generation for EMI reduction in PCIe systems. Operating on a full 3.3V supply, it ensures compliance with PCI Express Gen 1, Gen 2, and Gen 3 jitter specifications.

Specialized ICS Feature Summary

• Generates 100MHz, 125MHz, 200MHz, and 400MHz frequencies from a 25MHz crystal input
• Two 0.7V differential HCSL outputs and one LVCMOS/LVTTL reference output
• Configurable spread-spectrum modulation (32kHz, -0.5%) for PCIe EMI reduction
• RMS phase jitter of 1.21ps typical at 200MHz (12kHz–20MHz)
• Compliant with PCI Express Gen 1, Gen 2, and Gen 3 jitter requirements

Specialized ICS Applications

• PCI Express Gen 1 (2.5 Gb/s), Gen 2 (5 Gb/s), and Gen 3 (8 Gb/s) systems
• High-speed serial Rapid I/O (sRIO) clock generation
• Telecom, networking, and industrial communication processors
• DSPs, switches, and bridges requiring precise low-jitter clocks

Specialized ICS Procurement Notes

Verify the package type matches the 32-VFQFN (5x5mm) specification. Confirm the datasheet revision A documentation aligns with the specific manufacturing lot. Ensure the supplier provides RoHS 6 lead-free compliant units as specified in the product description.

Specialized ICS Selection Notes

Select this component when a single solution replaces multiple oscillators and fanout buffers for PCIe or sRIO designs. Verify that the required output frequency (100MHz, 125MHz, 200MHz, or 400MHz) matches the FSEL pin configuration. Ensure the system design accommodates the 3.3V power supply and thermal requirements for the exposed pad VFQFN package.

Specialized ICS Part Context

This part belongs to the ICS841402I FemtoClock series by Integrated Device Technology, now part of Renesas Electronics. It is specifically optimized for high-speed serial interfaces like PCIe and sRIO, offering low jitter performance and flexible output configurations compared to standard clock generators.

Specialized ICS Replacement Considerations

Direct substitutes include other ICS841402 variants with different packaging or temperature grades. Cross-reference with IDT/Renesas clock generator families for similar functionality if pin compatibility is not required.

Specialized ICS FAQ

What is the maximum RMS phase jitter for this device?

The typical RMS phase jitter is 1.21ps at 200MHz (12kHz–20MHz offset range). Maximum limits vary by frequency and bandwidth per PCIe specifications.

How is spread-spectrum modulation configured?

Spread-spectrum is enabled by setting the SSM pin high. It operates at a 32kHz modulation frequency with a -0.5% down-spread factor.

Can the REF_OUT pin be used in PCIe Gen 2 and Gen 3 applications?

No, the datasheet recommends disabling the REF_OUT output in PCIe Gen 2 and Gen 3 applications to ensure proper jitter compliance.