MC88915FN70R2

Clock Generators, PLLs, Frequency Synthesizers Overview

The MC88915FN70R2 is a PLL-based clock driver IC manufactured by NXP USA Inc. (formerly Motorola). It utilizes phase-locked loop technology to lock low-skew outputs to an input reference clock, designed for high-performance PC and workstation clock distribution. The device features five Q outputs 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 supports frequency multiplication and division ratios of 2:1, 1:1, and 1:2. The FN70 variant guarantees a maximum operating frequency of 70 MHz on the 2X_Q output and 35 MHz on the Q outputs. It operates on a single 4.75V to 5.25V supply in a 28-lead PLCC package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• PLL-based clock distribution with <500 ps output-to-output skew between Q0-Q4 rising edges
• Maximum operating frequency of 70 MHz (2X_Q) and 35 MHz (Q outputs)
• Programmable frequency ratios (2:1, 1:1, 1:2) via feedback configuration and FREQ_SEL pin
• Test mode capability via PLL_EN pin for low-frequency board-level testing

Clock Generators, PLLs, Frequency Synthesizers Applications

• Clock distribution for high-performance personal computers
• System clock synchronization for workstations
• Multi-processing systems requiring synchronous board-to-board clock distribution

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify component authenticity as the MC88915 series is discontinued. Confirm the specific suffix 'FN70' indicates the 70 MHz speed grade, distinct from the 55 MHz 'FN55' variant. Check RoHS compliance status, as original Motorola versions may not meet current environmental standards. Ensure proper handling for static-sensitive devices upon receipt.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the MC88915FN70R2 when a maximum system frequency of 70 MHz is required. Choose this over the FN55 variant if the design demands higher VCO frequencies or faster edge rates. Ensure the application can accommodate the 28-lead PLCC package and provides adequate bypass capacitance (0.1 µF and 10 µF) near the analog pins to minimize jitter.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component belongs to the MC88915 family of timing solutions originally developed by Motorola. The 'FN' suffix denotes the Plastic Leaded Chip Carrier (PLCC) package type. The '70' indicates the guaranteed maximum frequency specification. The 'R2' typically refers to the tape and reel packaging format used for surface-mount assembly.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Designers should evaluate modern clock drivers from NXP or other manufacturers that offer similar PLL functionality, lower skew specifications, and RoHS-compliant packaging.