How to Use Step-Down Converter 12V to 5V, Charging module circuit, QC2.0/QC23.0 Protocol Support: 2-Channels: Examples, Pinouts, and Specs

The ENGLAB Buck Converter 12V→5V is a high-efficiency step-down (buck) converter designed to convert a 12V DC input to a stable 5V DC output. This module supports Quick Charge (QC) 2.0 and QC 3.0 protocols, making it ideal for fast-charging applications. With dual-channel output capability, it can simultaneously power multiple devices or circuits. Its compact design and robust performance make it suitable for a wide range of applications, including mobile device charging, embedded systems, and automotive electronics.

• Fast-charging mobile devices (QC2.0/QC3.0 support)
• Powering 5V microcontrollers (e.g., Arduino, Raspberry Pi)
• Automotive USB power supplies
• Battery-powered systems
• General-purpose DC-DC voltage regulation

The following table outlines the key technical specifications of the ENGLAB Buck Converter 12V→5V:

The module has the following pinout:

1. Connect the Input Voltage:

   • Connect the positive terminal of your 12V DC power source to the VIN+ pin.
   • Connect the ground terminal of your power source to the VIN- pin.

2. Connect the Output Load:

   • For Channel 1, connect the load's positive terminal to VOUT1+ and the ground terminal to VOUT1-.
   • For Channel 2, connect the load's positive terminal to VOUT2+ and the ground terminal to VOUT2-.

3. Enable QC Protocol (Optional):

   • If you need to use Quick Charge functionality, pull the QC_EN pin high using a 3.3V or 5V logic signal.

4. Power On:

   • Turn on the 12V DC power source. The module will regulate the input voltage to provide a stable 5V output.

• Input Voltage Range: Ensure the input voltage is within the specified range (6V to 32V). Exceeding this range may damage the module.
• Heat Dissipation: For high-current applications, ensure proper heat dissipation by adding a heatsink or improving airflow around the module.
• Load Current: Do not exceed the maximum output current of 3A per channel to avoid overheating or damage.
• QC Protocol: If using the QC2.0/QC3.0 protocol, ensure the connected device supports these standards.

The module can be used to power an Arduino UNO from a 12V battery. Here's how to connect it:

1. Connect the 12V battery's positive terminal to VIN+ and the negative terminal to VIN-.
2. Connect VOUT1+ to the Arduino's 5V pin and VOUT1- to the Arduino's GND pin.

If you want to control the QC_EN pin using the Arduino, you can use the following code:

// Define the QC_EN pin
const int QC_EN_PIN = 7;

void setup() {
  // Set QC_EN_PIN as an output
  pinMode(QC_EN_PIN, OUTPUT);

  // Enable QC protocol by setting the pin HIGH
  digitalWrite(QC_EN_PIN, HIGH);

  // Optional: Add a delay to ensure stable operation
  delay(100);
}

void loop() {
  // The QC_EN pin remains HIGH to enable QC protocol
  // Add your main code here
}

1. No Output Voltage:

   • Cause: Input voltage is not connected or is outside the specified range.
   • Solution: Verify the input voltage is between 6V and 32V and properly connected.

2. Overheating:

   • Cause: Excessive load current or poor heat dissipation.
   • Solution: Reduce the load current or add a heatsink to the module.

3. QC Protocol Not Working:

   • Cause: QC_EN pin is not enabled or the connected device does not support QC2.0/QC3.0.
   • Solution: Pull the QC_EN pin high and ensure the connected device supports QC protocols.

4. Voltage Drop Under Load:

   • Cause: Input power source cannot supply sufficient current.
   • Solution: Use a power source with a higher current rating.

Q1: Can I use this module with a 24V input?
A1: Yes, the module supports input voltages up to 32V. Ensure the input voltage is stable and within the specified range.

Q2: Can I connect both channels to the same load?
A2: No, each channel is designed to operate independently. Connecting them together may cause instability or damage.

Q3: Is the module protected against reverse polarity?
A3: No, the module does not have built-in reverse polarity protection. Always double-check your connections before powering on.

Q4: Can I use this module to charge a Li-ion battery?
A4: Yes, but ensure the battery charging circuit is compatible with a 5V input and supports QC protocols if needed.