How to Use SN74HC193N FIAX: Examples, Pinouts, and Specs

The SN74HC193N FIAX is a high-speed, 4-bit binary up/down synchronous counter. This versatile component is widely used in digital electronics for counting applications, such as frequency division, event counting, and time measurement. It features a wide operating voltage range and low power consumption, making it suitable for various applications in both consumer and industrial electronics.

1. Power Supply: Connect the Vcc pin (16) to a power supply within the range of 2V to 6V. Connect the GND pin (8) to the ground of the power supply.
2. Clock Inputs: Use the CPU (3) and CPD (2) pins to provide clock pulses for counting up and down, respectively.
3. Reset: To reset the counter, apply a low signal to the MR (1) pin.
4. Parallel Load: To load a parallel value into the counter, apply a low signal to the PE (11) pin and provide the desired value on the P0 (12), P1 (13), P2 (14), and P3 (15) pins.
5. Outputs: The current count value can be read from the Q1 (4), Q2 (5), Q3 (6), and Q4 (7) pins.

• Debouncing: Ensure that the clock inputs (CPU and CPD) are debounced to avoid erroneous counting due to noise or mechanical switch bounce.
• Power Supply Decoupling: Use a decoupling capacitor (e.g., 0.1µF) close to the Vcc pin to filter out noise from the power supply.
• Unused Inputs: Tie any unused inputs to a defined logic level (either Vcc or GND) to prevent floating inputs, which can cause unpredictable behavior.

/*
  Example code to interface SN74HC193N FIAX with Arduino UNO
  This code increments the counter every second and prints the count
  to the serial monitor.
*/

const int clockUpPin = 2;  // Pin connected to CPU (Clock Pulse Up)
const int resetPin = 3;    // Pin connected to MR (Master Reset)
const int q1Pin = 4;       // Pin connected to Q1 (Output Bit 1)
const int q2Pin = 5;       // Pin connected to Q2 (Output Bit 2)
const int q3Pin = 6;       // Pin connected to Q3 (Output Bit 3)
const int q4Pin = 7;       // Pin connected to Q4 (Output Bit 4)

void setup() {
  pinMode(clockUpPin, OUTPUT);
  pinMode(resetPin, OUTPUT);
  pinMode(q1Pin, INPUT);
  pinMode(q2Pin, INPUT);
  pinMode(q3Pin, INPUT);
  pinMode(q4Pin, INPUT);

  Serial.begin(9600);

  // Reset the counter
  digitalWrite(resetPin, LOW);
  delay(10);
  digitalWrite(resetPin, HIGH);
}

void loop() {
  // Generate a clock pulse to increment the counter
  digitalWrite(clockUpPin, HIGH);
  delay(10);
  digitalWrite(clockUpPin, LOW);

  // Read the counter value
  int count = (digitalRead(q4Pin) << 3) |
              (digitalRead(q3Pin) << 2) |
              (digitalRead(q2Pin) << 1) |
              digitalRead(q1Pin);

  // Print the count to the serial monitor
  Serial.print("Count: ");
  Serial.println(count);

  delay(1000);  // Wait for 1 second
}

1. Counter Not Incrementing/Decrementing:

   • Solution: Ensure that the clock pulses are correctly applied to the CPU or CPD pins. Check for proper debouncing of the clock signals.

2. Unexpected Count Values:

   • Solution: Verify that all input pins are connected to defined logic levels. Floating inputs can cause unpredictable behavior.

3. Counter Resets Unexpectedly:

   • Solution: Check the MR pin to ensure it is not being inadvertently pulled low. Ensure stable power supply and proper decoupling.

Q1: Can I use the SN74HC193N FIAX with a 3.3V power supply?

• A1: Yes, the SN74HC193N FIAX can operate with a supply voltage range of 2V to 6V, so 3.3V is within the acceptable range.

Q2: How can I cascade multiple SN74HC193N FIAX counters for higher bit counts?

• A2: Connect the terminal count output (TCUP or TCDN) of the first counter to the clock input (CPU or CPD) of the next counter. This way, the second counter will increment/decrement when the first counter overflows/underflows.

Q3: What is the maximum counting frequency of the SN74HC193N FIAX?

• A3: The maximum counting frequency is determined by the propagation delay, which is typically 15ns. This translates to a maximum frequency of approximately 66.7MHz.

By following this documentation, users can effectively integrate the SN74HC193N FIAX into their projects, ensuring reliable and accurate counting operations.