The M74HC191 is a high speed CMOS 4-bit synchronous up/down counter fabricated with silicon gate C2MOS technology. State changes of the counter are synchronous with the LOW-to-HIGH transition of the Clock Pulse Input. An asynchronous parallel load input overrides counting and loads the data present on the DATA inputs into the flip-flops, which makes it possible to use the circuits as programmable counters. A count enable input serves as the carry/borrow input in multi-stage counters. Control input, Down/ Up, determines whether a circuit counts up or down. A MAX/MIN output and a Ripple Clock output provide overflow/underflow indication and make possible a variety of methods for generating carry/borrow signals in multi-stage counter applications. All inputs are equipped with protection circuits against static discharge and transient excess voltage.
The M74HC191 is a high-speed CMOS 4-bit synchronous up/down counter fabricated with silicon gate CMOS technology. State changes occur on the LOW-to-HIGH transition of the Clock Pulse Input. The device features an asynchronous parallel load input that overrides counting to load data present on the DATA inputs, allowing use as a programmable counter. A count enable input serves as a carry/borrow input in multi-stage counters.
| Operating Voltage Range | 2V to 6V |
|---|---|
| Supply Voltage (Absolute Max) | -0.5 to +7 V |
| Operating Temperature Range | -55 to 125 °C |
| Number of Bits | 4-Bit |
The asynchronous parallel load input overrides counting and loads the data present on the DATA inputs into the flip-flops.
State changes of the counter are synchronous with the LOW-to-HIGH transition of the Clock Pulse Input.