The MM54C90 and MM74C90 are 4-bit decade counters, and the MM54C93 and MM74C93 are 4-bit binary counters. They are complementary MOS (CMOS) integrated circuits constructed with N- and P-channel enhancement mode transistors. The 4-bit decade counter can reset to zero or preset to nine by applying appropriate logic level on the R01, R02, R91 and R92 inputs. Also, a separate flip-flop on the A-bit enables the user to operate it as a divide-by-2, 5 or 10 frequency counter. The 4-bit binary counter can be reset to zero by applying high logic level on inputs R01 and R02, and a separate flip-flop on the A-bit enables the user to operate it as a divide-by-2, -8 or -16 divider. Counting occurs on the negative going edge of the input pulse. All inputs are protected against static discharge damage.
This document is a datasheet for the MM54C90/MM74C90 4-bit decade counter and the MM54C93/MM74C93 4-bit binary counter. These complementary MOS (CMOS) integrated circuits are constructed with N- and P-channel enhancement mode transistors and feature a wide supply voltage range from 3V to 15V.
| Supply Voltage Range | 3V to 15V |
|---|---|
| Maximum Clock Frequency (5V) | 2 MHz |
The operating temperature range for these models is from -58°C to +125°C.