ICS8432BY-51LF

Clock Generators, PLLs, Frequency Synthesizers Overview

The ICS8432BY-51LF is a dual-output, crystal-to-3.3V differential LVPECL frequency synthesizer from the HiPerClockS family. It features an integrated PLL with a VCO operating between 250MHz and 700MHz. The device accepts a selectable crystal input (12MHz–25MHz) or LVCMOS/LVTTL REF_CLK. Output frequencies range from 31.25MHz to 700MHz via programmable M and N dividers. Key performance metrics include a maximum RMS period jitter of 3.5ps and cycle-to-cycle jitter of 25ps. It operates on a single 3.3V supply within a 0°C to 70°C temperature range.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Dual differential 3.3V LVPECL outputs with low phase noise characteristics
• Integrated PLL requiring no external loop bandwidth components
• Selectable crystal oscillator interface (12MHz–25MHz) or LVCMOS/LVTTL reference clock
• Programmable via parallel or serial interface for M and N divider configuration

Clock Generators, PLLs, Frequency Synthesizers Applications

• Gigabit Ethernet clock generation
• Fibre Channel 1 and 2 synchronization
• Infiniband system timing

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify that the ordering suffix 'BY' corresponds to the lead-free (RoHS 6) package variant as specified in the datasheet. Confirm the package type matches the required board layout, as the device is available in both 32-Lead LQFP and 32-Lead VFQFN configurations. Ensure the specific revision level meets design requirements.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when low jitter (<3.5ps RMS) and high-frequency output (up to 700MHz) are required for differential LVPECL loads. Choose based on the input source: use the crystal interface for standalone oscillation or the REF_CLK pin for external reference injection. Verify thermal constraints for the chosen package (LQFP vs. VFQFN) under maximum load conditions.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The ICS8432BY-51 replaces the earlier ICS8432-01 model. It belongs to the HiPerClockS family of high-performance clock solutions manufactured by IDT (now part of Renesas Electronics). The device is designed to provide precise clock distribution for high-speed data communication standards.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

The datasheet explicitly states that this device replaces the ICS8432-01. When substituting, verify that the previous design utilized compatible LVPECL outputs and that the new M/N divider programming settings match the original frequency requirements.

Clock Generators, PLLs, Frequency Synthesizers FAQ

What is the valid range for the M divider value?

For a 25MHz reference, valid M values for PLL lock are defined as 10 ≤ M ≤ 28.

How is the VCO frequency determined?

The VCO frequency is calculated as fVCO = fxtal × M, where fxtal is the crystal/reference frequency and M is the programmed divider value.

Can unused LVPECL outputs be left floating?

Yes, unused LVPECL outputs can be left floating, though it is recommended that no trace be attached to them.