MC88915FN70

Clock Generators, PLLs, Frequency Synthesizers Overview

The MC88915FN70 is a CMOS PLL clock driver designed for high-performance PC and workstation applications. It features five low-skew outputs (Q0–Q4) with less than 500 ps skew, plus inverted Q5, doubled 2X_Q, and divided Q/2 outputs. The device locks frequency and phase to a single reference input, supporting ratios of 1:2, 1:1, and 2:1. Operating at a maximum 2X_Q frequency of 70 MHz, it accepts TTL-compatible inputs and provides ±36 mA drive capability for CMOS/TTL loads. Powered by a 4.75V to 5.25V supply, it utilizes a 28-lead PLCC package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Five phase-locked outputs (Q0-Q4) with output-to-output skew under 500 ps
• Supports 1:2, 1:1, and 2:1 input-to-output frequency ratios via feedback configuration
• Maximum operating frequency of 70 MHz on the 2X_Q output
• Includes test mode pin (PLL_EN) for low-frequency board testing

Clock Generators, PLLs, Frequency Synthesizers Applications

• Clock distribution for high-performance personal computers
• Synchronous clocking in multi-board workstation systems
• Frequency multiplication from low-frequency references to higher system clocks

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify component authenticity as this part originates from Motorola legacy lines now managed by NXP USA Inc. Confirm the FN suffix indicates the standard plastic PLCC package. Check RoHS compliance status, as original specifications may predate modern environmental directives. Ensure the 70 MHz speed grade matches design requirements rather than the 55 MHz variant.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the MC88915FN70 when a 70 MHz maximum 2X_Q frequency is required, distinguishing it from the 55 MHz MC88915FN55. Ensure the application supports a 5V logic environment, as the device requires a 4.75V to 5.25V supply. Verify that the PCB layout can accommodate the specific analog loop filter components and bypass capacitors detailed in the datasheet to maintain signal integrity.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component belongs to the MC88915 family of timing solutions originally developed by Motorola. The FN70 designation specifically denotes the 70 MHz performance grade within the Plastic Leadless Chip Carrier (PLCC) package format. It serves as a specialized clock generator for synchronous digital systems requiring precise phase alignment across multiple destinations.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

The MC88915FN55 is a verified lower-speed substitute offering a 55 MHz maximum 2X_Q frequency. Both share identical pinouts and functional characteristics. No other direct cross-model replacements are documented in the provided source material.