MC88915EI55R2

Clock Generators, PLLs, Frequency Synthesizers Overview

The MC88915EI55R2 is a low skew CMOS PLL clock driver in a 28-lead PLCC package. It locks multiple outputs to a single reference input, providing frequency multiplication and distribution for high-performance systems. The device features five Q outputs (Q0–Q4) with less than 500 ps skew, an inverted Q5 output, a 2X_Q output running at twice the Q frequency, and a Q/2 output. It operates at VCC = 5.0 V ± 5%. The FN55 suffix guarantees a maximum 2X_Q frequency of 55 MHz, while FN70 guarantees 70 MHz. Outputs provide ±36 mA drive capability.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Five Q outputs (Q0-Q4) with <500 ps output-to-output skew
• PLL technology enables frequency multiplication (2X) and division (Q/2)
• Programmable FREQ_SEL pin allows divide-by-1 or divide-by-2 feedback selection
• Test mode via PLL_EN pin for low-frequency board testing without PLL lock

Clock Generators, PLLs, Frequency Synthesizers Applications

• Clock distribution for high-performance PCs and workstations
• Synchronous clock distribution to multiple boards from a central system clock
• Multiprocessing applications requiring low board-to-board skew

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the ordering suffix EI55R2 against the manufacturer's current catalog. The 'EI' indicates a 28-lead PLCC Pb-free package. The '55' denotes the FN55 speed grade (55 MHz max 2X_Q). Confirm if 'R2' corresponds to a specific tape-and-reel quantity or revision, as datasheets may not explicitly define all suffix variations. Ensure compatibility with 5V logic levels.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select based on required maximum operating frequency; choose FN55 for up to 55 MHz or FN70 for up to 70 MHz on the 2X_Q output. Ensure the application requires a 5V supply, as this device is not compatible with 3.3V logic directly. Consider the need for a test mode feature if low-frequency board testing is required. Verify that the 28-lead PLCC package fits the PCB layout constraints.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component is part of the IDT/ICS CMOS PLL Clock Driver family, originally manufactured by Integrated Device Technology (IDT), which was later acquired by Renesas Electronics Corporation. The MC88915 is designed to replace older clock buffer solutions by integrating the PLL and distribution buffers into a single low-skew package, reducing board space and improving signal integrity in synchronous digital systems.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Direct replacements must match the 28-lead PLCC package and 5V operation. Check for updated Renesas part numbers that may have superseded the IDT branding. Ensure any substitute supports the same frequency ranges (FN55/FN70) and provides similar skew specifications (<500 ps). Verify that the replacement includes the same control pins (FREQ_SEL, PLL_EN) for equivalent functionality.