How to Use Logic Level Shifter, 4-Channel, Bidirectional: Examples, Pinouts, and Specs

The Pololu Logic Level Shifter is a versatile device designed to facilitate the safe and efficient translation of voltage levels between different parts of a circuit. This component supports four channels and bidirectional communication, making it ideal for interfacing devices that operate at different voltage levels. Common applications include connecting 3.3V sensors to a 5V microcontroller, interfacing between different logic families, and enabling communication between devices with different voltage requirements.

1. Power Connections:

   • Connect the LV pin to the low voltage supply (e.g., 3.3V).
   • Connect the HV pin to the high voltage supply (e.g., 5V).
   • Connect the GND pin to the ground of the circuit.

2. Channel Connections:

   • For each channel, connect the A side to the low voltage device and the B side to the high voltage device.
   • For example, to translate a signal from a 3.3V sensor to a 5V microcontroller, connect the sensor output to A1 and the microcontroller input to B1.

• Ensure that the voltage levels on the LV and HV pins are within the specified range (1.8V to 6V).
• Do not exceed the maximum current rating of 50mA per channel.
• Keep the ground connections common between the low and high voltage sides to ensure proper operation.
• Use decoupling capacitors close to the LV and HV pins to filter out noise and stabilize the voltage levels.

Here is an example of how to connect a 3.3V sensor to a 5V Arduino UNO using the Pololu Logic Level Shifter:

3.3V Sensor       Logic Level Shifter       Arduino UNO
   VCC  --------> LV (3.3V)
   GND  --------> GND --------------------> GND
   OUT  --------> A1                       B1 --------> Digital Pin 2

// Example code to read a 3.3V sensor output using a 5V Arduino UNO
const int sensorPin = 2; // Pin connected to B1 of the level shifter

void setup() {
  Serial.begin(9600); // Initialize serial communication
  pinMode(sensorPin, INPUT); // Set the sensor pin as input
}

void loop() {
  int sensorValue = digitalRead(sensorPin); // Read the sensor value
  Serial.println(sensorValue); // Print the sensor value to the serial monitor
  delay(1000); // Wait for 1 second before reading again
}

1. No Signal Translation:

   • Solution: Ensure that the LV and HV pins are connected to the correct voltage levels and that the ground is common between the low and high voltage sides.

2. Intermittent Operation:

   • Solution: Check for loose connections and ensure that decoupling capacitors are used near the LV and HV pins.

3. Overheating:

   • Solution: Verify that the current through each channel does not exceed 50mA. If necessary, use current-limiting resistors.

1. Can I use the level shifter for I2C communication?

   • Yes, the Pololu Logic Level Shifter supports bidirectional communication and can be used for I2C signals.

2. What is the maximum frequency the level shifter can handle?

   • The level shifter can handle frequencies up to 10MHz, making it suitable for most common digital communication protocols.

3. Can I use the level shifter with a 1.8V device?

   • Yes, the level shifter supports voltage levels as low as 1.8V on both the LV and HV sides.

By following this documentation, users can effectively integrate the Pololu Logic Level Shifter into their projects, ensuring safe and reliable voltage level translation.