MC10H640FNR2

Overview

The MC10H640FNR2 is a clock driver designed for 68030 and 68040 microprocessors. It accepts PECL or TTL inputs and provides six TTL outputs with a 2:6 ratio. The device operates on a single +5.0 V supply (4.75V to 5.25V) and supports frequencies up to 135 MHz. It features differential input/output, asynchronous reset, and internal divide-by-two/four stages. Packaged in a 28-PLCC surface-mount case, it ensures part-to-part and within-part skew compliance for MPU clock generation.

Feature Summary

• Generates clocks for 68030/040 MPUs meeting specific skew requirements
• Accepts both TTL and PECL input signals via Select pin
• Includes internal ÷2 and ÷4 stages for duty cycle control
• Asynchronous Reset forces all Q outputs LOW

Applications

• Clock distribution for Motorola 68030 microprocessors
• Clock distribution for Motorola 68040 microprocessors
• High-speed digital system timing synchronization

Procurement Notes

Verify the RoHS status of the specific lot, as datasheets indicate compliance while distributor listings may vary. Confirm package availability, as the FNR2 suffix denotes tape-and-reel packaging. Check for end-of-life notices or alternative sourcing options from authorized distributors like Rochester Electronics if standard production is discontinued.

Selection Notes

Select this component when driving 68030/040 processors requiring precise skew management. Ensure the input signal matches the selected mode (TTL vs. PECL) via the SEL pin. Verify load capacitance limits to maintain duty cycle accuracy at high frequencies. Consider the 28-PLCC footprint for PCB layout compatibility.

Part Context

Part of the MC10H series ECL/TTL logic family by onsemi. Related models include MC10H642 (2:8 ratio), MC10H645 (1:9 ratio), and MC10H646 (2:8 ratio). These devices share similar packaging and power supply characteristics but differ in output ratios and maximum frequencies.

Replacement Considerations

MC10H642FNR2 offers a 2:8 ratio instead of 2:6. MC10H646FNR2 provides a 2:8 ratio with an 80 MHz max frequency. Verify pinout compatibility and output count before substitution.