FAIRCHILD MM74C925 MM74C926 MM74C927 MM74C928 4-Digit Counters with Multiplexed 7-Segment Output Drivers handbook

About this manual

The document details four models of CMOS counters: the MM74C925 (basic 4-decade counter), the MM74C926 (adds display select and carry-out), the MM74C927 (second digit divides by 6 for seconds/minutes), and the MM74C928 (most significant digit divides by 2, acting as a 314-digit counter). All models feature internal multiplexing circuitry with a free-running oscillator requiring no external clock.

Key features include a wide supply voltage range of 3V to 6V, high noise immunity, and the ability to source up to 40 mA per segment. The devices operate over an industrial temperature range of -40°C to +85°C and are available in Ceramic Dual-In-Line (J) and Molded Dual-In-Line (N) packages.

What's inside

• General Description
• Features
• Design Considerations
• Absolute Maximum Ratings
• DC Electrical Characteristics
• AC Electrical Characteristics
• Functional Description
• Logic and Block Diagrams
• Switching Time Waveforms
• Physical Dimensions

Specifications

Frequently asked questions

Does the MM74C928 count to a higher value than standard counters?

Yes, it is a 314-digit counter because its most significant digit divides by 2 rather than 10.

Is an external clock required for the multiplexing circuit?

No, the internal multiplexing circuit has its own free-running oscillator and requires no external clock.