CDC421A156RGER

Clock Generators, PLLs, Frequency Synthesizers Overview

The CDC421A156RGER is a fixed-frequency clock synthesizer and jitter cleaner manufactured by Texas Instruments. It integrates a crystal oscillator circuit with an LC-based voltage-controlled oscillator (VCO) to generate precise clock signals. The device operates on a single 3.3 V power supply, with a voltage range of 3 V to 3.6 V. It accepts crystal or LVCMOS inputs at frequencies such as 31.25 MHz, 33.33 MHz, or 35.42 MHz. The output provides a differential LVPECL signal at a maximum frequency of 156.25 MHz. Packaged in a 24-VQFN exposed pad, it functions within an industrial temperature range of -40°C to +85°C.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrates low-noise LC-based VCO for high-performance clock generation
• Provides differential LVPECL outputs for high-speed, low-noise signaling
• Supports multiple input frequencies via crystal or LVCMOS interfaces
• Includes chip enable control for power management

Clock Generators, PLLs, Frequency Synthesizers Applications

• Communication systems requiring stable clock distribution
• Data processing equipment needing low-jitter timing
• Industrial control systems operating in harsh environments

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific suffix 'GER' against official datasheets to confirm package type and tape/reel specifications. Ensure compatibility with existing PCB footprints for the 24-VQFN package. Confirm moisture sensitivity level handling requirements during assembly. Validate that the fixed 156.25 MHz output meets system timing constraints without additional buffering.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when a fixed 156.25 MHz LVPECL clock is required from a lower frequency crystal input. Compare RMS jitter performance against other family members if stricter phase noise limits are necessary. Consider the 24-VQFN package size for space-constrained designs. Verify that the single 3.3 V supply aligns with the target board's power architecture.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This part belongs to the CDC421Axxx series of low-jitter clock generators. It shares architectural similarities with variants like the CDC421A100RGET and CDC421A106RGET, differing primarily in the fixed output frequency. The series is designed for applications demanding high signal integrity and simplified design through integrated oscillators.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Direct substitutes include other CDC421A156 variants with compatible packaging. Cross-reference pinouts and electrical characteristics with similar TI clock synthesizers before substitution.