MC10H640FN

Overview

The MC10H640FN is a single-supply clock driver designed for 68030 and 68040 microprocessors. It translates PECL or TTL inputs to six TTL outputs with a 2:6 ratio. The device operates on a +5.0 V supply, supporting frequencies up to 135 MHz. Key electrical parameters include a maximum propagation delay of 7.0 ns from reset and within-device skew of 0.5 ns at 25°C. It features integrated divide-by-two and divide-by-four stages for duty cycle control. The component is housed in a 28-lead PLCC package and functions within an operating temperature range of 0°C to 85°C.

Feature Summary

• Generates clocks for 68030/040 MPUs with guaranteed part-to-part and within-part skew.
• Accepts both TTL and PECL (ECL referenced to +5.0 V) input clock sources.
• Includes asynchronous reset and internal divide-by-two/four stages for duty cycle adjustment.
• Provides extra TTL and ECL power/ground pins for improved signal integrity.

Applications

• Clock generation for Motorola 68030 microprocessors.
• Clock generation for Motorola 68040 microprocessors.
• High-speed clock distribution systems requiring low skew.

Procurement Notes

Verify the specific ordering suffix 'FN' corresponds to the 28-PLCC package configuration. Confirm RoHS compliance status for the exact batch, as older revisions may differ. Ensure the application voltage remains strictly within the 4.75V to 5.25V range to maintain specified AC characteristics. Check for lead-free markings if environmental compliance is required.

Selection Notes

Select this component when interfacing differential PECL or single-ended TTL signals to multiple TTL loads for legacy 68k processors. Consider the 135 MHz maximum frequency limit against the system clock requirements. Evaluate the 25 pF load capacitance conditions for accurate propagation delay calculations. Verify that the 28-PLCC footprint matches the PCB design constraints.

Part Context

The MC10H640 belongs to the H64x series of clock drivers specialized for high-performance microprocessor applications. It utilizes internal differential PECL circuitry to achieve superior skew characteristics compared to standard logic families. The device integrates necessary division stages to meet specific MPU timing requirements without external components.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Designers should consult official replacement guides or contact the manufacturer for equivalent devices with updated packaging or compliance statuses.