74LS169 DIP 4-Bit Synchronous Binary Up-Down Counter
The 74LS169 is a high speed TTL integrated circuit that functions as a fully synchronous 4-bit reversible binary counter. This device is designed for high performance digital systems where both incrementing and decrementing capabilities are required. Because all flip-flops are clocked simultaneously, the outputs change state in unison on the positive-going transition of the clock, eliminating the asynchronous glitches and spikes found in ripple counters.
The IC features a dedicated up-down control input that determines the direction of the count. It is also fully presettable, allowing any 4-bit binary value to be loaded into the counter via the parallel data inputs when the load line is active low. To facilitate easy expansion into larger counting arrays, the 74LS169 includes internal carry look-ahead circuitry, two count enable inputs, and a ripple carry output. This makes it ideal for digital tuning, frequency synthesis, and complex motion control systems.
KEY FEATURES
- Synchronous 4-bit binary counting for high speed timing
- Reversible counting direction with Up/Down control
- Fully presettable parallel inputs for programmable start values
- Internal look-ahead carry for seamless cascading
- Low power Schottky technology for optimal efficiency
- Standard 16 pin dual in line package
SPECIFICATIONS
- Supply Voltage 4.75V to 5.25V
- Operating Temperature 0 to 70 Celsius
- Logic Type TTL Low Power Schottky
- Maximum Clock Frequency 25MHz
- Typical Power Dissipation 100mW
- High Level Output Current -0.4mA
- Low Level Output Current 8mA
INTERFACES
- CLK Clock input positive edge triggered
- U/D Up-down count control input
- LOAD Parallel load input active low
- ENP Count enable P input
- ENT Count enable T input for carry logic
- A B C D Parallel data inputs
- QA QB QC QD Binary counter outputs
- RCO Ripple carry output active low
- VCC Positive supply voltage
- GND Ground reference
