Product Overview
Motorola 1820-0821 / MC10136L MECL 10K Universal Counter IC
Condition
New old stock (NOS). Unused vintage component with clean leads and intact ceramic dual in-line package. Body markings legible: Motorola emblem, 1820-0821, and date code 7521.
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Product Overview
The Motorola 1820-0821 is an emitter-coupled logic (MECL 10,000 series) 4-bit universal binary and hexadecimal up/down counter housed in a 16-pin ceramic DIP. Produced under Hewlett-Packard custom part number 1820-0821, this high-speed integrated circuit corresponds directly to the industry-standard MC10136L. Designed for high-frequency test instrumentation, it features synchronous counting and presetting capabilities with typical toggle frequencies up to 150 MHz.
Key Features
- MECL 10K emitter-coupled logic architecture
- 4-bit universal synchronous up/down binary and hexadecimal counting
- 150 MHz typical toggle frequency for high-speed prescaling and counting
- Nominal operating supply voltage of -5.2 V (VEE)
- 16-pin ceramic dual in-line package (CDIP-16 / CERDIP)
- Direct cross-reference for HP part number 1820-0821 and Motorola MC10136L
Applications
- Restoring vintage Hewlett-Packard RF analyzers, synthesizers, and frequency counters
- Servicing legacy high-speed logic subsystems in legacy laboratory test equipment
- Breadboarding high-speed digital clock division circuits for retrocomputing projects
Frequently Asked Questions
Is HP part number 1820-0821 interchangeable with Motorola MC10136L?
Yes. Hewlett-Packard service documentation cross-references internal part number 1820-0821 directly to Motorola component MC10136L in the ceramic 16-pin package.
What supply voltage does this ECL counter require?
Standard MECL 10K logic requires a nominal supply voltage of -5.2 V (VEE) referenced to ground.
Why buy this specific vintage counter IC instead of taking chances on an untracked lot?
You receive the exact new old stock Motorola component photographed, verified with markings 1820-0821 and date code 7521, avoiding the risk of counterfeit or worn pulls. Orders ship for an $8 flat rate, free once the order passes $28, and leave our Idaho warehouse the same or next business day.
Before microcontrollers took over the bench, serious timing meant emitter-coupled logic running hot and ticking fast. Drop this into your HP instrument or timing build and let the circuit pick right back up where 1975 left off.
