The 74LS173 is a quad D-type flip-flop manufactured by Texas Instruments. It features four D-type flip-flops with a common clock input and active-low enable inputs. This component is widely used in digital circuits for data storage and transfer, enabling the synchronization of data with a clock signal. Its compact design and reliable performance make it a popular choice in applications requiring temporary data storage or controlled data flow.
The following table outlines the key technical details of the 74LS173:
Parameter | Value |
---|---|
Supply Voltage (Vcc) | 4.75V to 5.25V |
Input Voltage (VI) | 0V to 7V |
High-Level Output Voltage | 2.7V (min) |
Low-Level Output Voltage | 0.4V (max) |
High-Level Input Current | 20 µA (max) |
Low-Level Input Current | -0.4 mA (max) |
Propagation Delay (typical) | 20 ns |
Operating Temperature Range | 0°C to 70°C |
Package Type | DIP-16, SOIC-16 |
The 74LS173 comes in a 16-pin package. The pinout and descriptions are as follows:
Pin Number | Pin Name | Description |
---|---|---|
1 | MR | Master Reset (Active Low) |
2 | G1 | Enable Input 1 (Active Low) |
3 | G2 | Enable Input 2 (Active Low) |
4 | D0 | Data Input 0 |
5 | D1 | Data Input 1 |
6 | D2 | Data Input 2 |
7 | D3 | Data Input 3 |
8 | GND | Ground |
9 | Q3 | Data Output 3 |
10 | Q2 | Data Output 2 |
11 | Q1 | Data Output 1 |
12 | Q0 | Data Output 0 |
13 | CLK | Clock Input |
14 | OE1 | Output Enable 1 (Active Low) |
15 | OE2 | Output Enable 2 (Active Low) |
16 | Vcc | Positive Supply Voltage |
The 74LS173 is straightforward to use in digital circuits. Below are the steps and considerations for proper usage:
The 74LS173 can be interfaced with an Arduino UNO for data storage and control. Below is an example code snippet:
// Example: Interfacing 74LS173 with Arduino UNO
// This code demonstrates how to control the 74LS173 flip-flop using Arduino.
// Pin definitions
const int clkPin = 2; // Clock signal
const int mrPin = 3; // Master Reset
const int g1Pin = 4; // Enable Input 1
const int g2Pin = 5; // Enable Input 2
const int dPins[] = {6, 7, 8, 9}; // Data inputs D0-D3
void setup() {
// Set pin modes
pinMode(clkPin, OUTPUT);
pinMode(mrPin, OUTPUT);
pinMode(g1Pin, OUTPUT);
pinMode(g2Pin, OUTPUT);
for (int i = 0; i < 4; i++) {
pinMode(dPins[i], OUTPUT);
}
// Initialize pins
digitalWrite(mrPin, HIGH); // Disable reset
digitalWrite(g1Pin, LOW); // Enable flip-flops
digitalWrite(g2Pin, LOW); // Enable flip-flops
digitalWrite(clkPin, LOW); // Initialize clock
}
void loop() {
// Example: Store and transfer data
for (int i = 0; i < 16; i++) {
// Set data inputs
for (int j = 0; j < 4; j++) {
digitalWrite(dPins[j], (i >> j) & 0x01); // Set each bit of D0-D3
}
// Generate clock pulse
digitalWrite(clkPin, HIGH);
delay(10); // Short delay for clock pulse
digitalWrite(clkPin, LOW);
delay(10);
}
}
Outputs Not Responding:
Unexpected Output States:
Outputs Stuck in High-Impedance:
Q1: Can the 74LS173 operate at 3.3V?
No, the 74LS173 is designed to operate within a supply voltage range of 4.75V to 5.25V. Using it at 3.3V may result in unreliable operation.
Q2: What happens if the MR pin is left floating?
The MR pin is active low and should not be left floating. If left unconnected, it may cause unpredictable behavior. Connect it to Vcc for normal operation or to GND to reset the outputs.
Q3: How do I cascade multiple 74LS173 ICs?
To cascade multiple ICs, connect the clock and enable inputs in parallel. Use the outputs of one IC as the inputs to the next stage for extended data storage or transfer.
By following this documentation, users can effectively integrate the 74LS173 into their digital circuits for reliable data storage and synchronization.