74193 IC 4-Bit Binary Up/Down Counter
The IC 74193 is a synchronous 4-bit binary up/down counter capable of counting from 0000 (0) to 1111 (15) in both up and down directions. It includes two separate clock inputs: CPU (Clock Pulse Up) for incrementing and CPD (Clock Pulse Down) for decrementing.
It provides an asynchronous clear (CLR) that immediately resets the counter to zero regardless of the clock and a parallel load (LOAD) that presets any 4-bit value into the counter.
The device has carry (TCU) and borrow (TCD) outputs, allowing cascading multiple counters to build larger counting ranges. The synchronous operation ensures that all outputs update simultaneously with the clock edge, avoiding glitches.
It is widely used in digital systems requiring bidirectional counting, frequency division, event counting, and programmable timing sequences.
Pin Configuration (DIP-16)
| Pin | Name | Description |
|---|---|---|
| 1 | B0 | Parallel Data Input (LSB) |
| 2 | B1 | Parallel Data Input |
| 3 | B2 | Parallel Data Input |
| 4 | B3 | Parallel Data Input (MSB) |
| 5 | CPU | Clock Pulse Up Input |
| 6 | CPD | Clock Pulse Down Input |
| 7 | TCD | Terminal Count Down (Borrow) Output |
| 8 | GND | Ground |
| 9 | TCU | Terminal Count Up (Carry) Output |
| 10 | Q0 | Output Bit 0 (LSB) |
| 11 | Q1 | Output Bit 1 |
| 12 | Q2 | Output Bit 2 |
| 13 | Q3 | Output Bit 3 (MSB) |
| 14 | LOAD | Parallel Load (active LOW) |
| 15 | CLR | Asynchronous Clear (active LOW) |
| 16 | VCC | +5V Power Supply |
Key Features
Synchronous 4-bit up/down binary counting (0–15)
Asynchronous clear for immediate reset
Parallel load for presetting values
Separate up and down clock inputs
Carry and borrow outputs for cascading
TTL-compatible logic levels
High-speed operation
Available in DIP-16 or SOIC-16
Applications
Build binary up/down counters for control circuits.
Divide frequencies in either direction.
Create event counters with reversible counting.
Implement programmable counters with load capability.
Cascade to form multi-bit counters.
Use in industrial automation counting systems.
Develop digital scoring and bidirectional displays.
Manage up/down sequences in robotic control.
Build elevator floor indicators.
Teach synchronous counter design in labs.
Specifications Table
| Parameter | Value |
|---|---|
| Logic Family | TTL |
| Function | Synchronous Binary Up/Down Counter |
| Count Range | 0–15 (mod-16) |
| Inputs | CPU, CPD, CLR, LOAD, B0–B3 |
| Outputs | Q0–Q3, TCU, TCD |
| Input HIGH Voltage | ≥ 2.0V |
| Input LOW Voltage | ≤ 0.8V |
| Output HIGH Voltage | ≥ 2.4V |
| Output LOW Voltage | ≤ 0.4V |
| Propagation Delay | ~25 ns ‘ |
| Max Clock Frequency | ~35 MHz |
| Supply Voltage (Vcc) | 4.75V to 5.25V |
| Operating Temp | 0°C to 70°C |
| Package Type | DIP-16 / SOIC-16 |
| Number of Pins | 16 |
