How to Use HV826MG_BACKLIGHT: Examples, Pinouts, and Specs

The HV826MG_BACKLIGHT is a high-voltage LED driver specifically designed for backlighting applications. It efficiently drives multiple LEDs with a constant current, ensuring uniform brightness and optimal performance in displays. This component is ideal for use in LCD backlighting, keypad illumination, and other applications requiring consistent LED brightness.

• LCD display backlighting
• Keypad and button illumination
• Automotive dashboard lighting
• Portable device displays
• Industrial control panels

• Input Voltage Range: 2.0V to 5.5V
• Output Voltage: Up to 220V
• Output Current: Configurable, up to 20mA
• Efficiency: Greater than 85% (typical)
• Operating Frequency: 50kHz to 200kHz
• Standby Current: <1µA
• Package Type: 8-pin MSOP (Micro Small Outline Package)
• Operating Temperature Range: -40°C to +85°C

The HV826MG_BACKLIGHT comes in an 8-pin MSOP package. Below is the pin configuration:

1. Power Supply: Connect the VIN pin to a stable power source within the range of 2.0V to 5.5V. Ensure proper decoupling with a capacitor (e.g., 1µF) close to the VIN pin.
2. Enable Pin: Use the EN pin to control the driver. Pull it high (logic 1) to enable the driver or low (logic 0) to disable it.
3. Current Setting: Connect a resistor to the RSET pin to set the desired output current. Use the formula provided in the datasheet to calculate the resistor value.
4. LED Connection: Connect the positive terminal of the LED string to the VOUT pin and the negative terminal to the FB pin.
5. Oscillator Configuration: Connect a capacitor to the OSC pin to set the operating frequency. Refer to the datasheet for recommended capacitor values.
6. Grounding: Ensure all ground connections are properly tied to the GND pin to avoid noise and instability.

• Thermal Management: Ensure adequate heat dissipation, especially when driving high-power LEDs.
• Component Placement: Place decoupling capacitors as close as possible to the VIN and GND pins.
• Feedback Resistor: Use precision resistors for the FB pin to maintain accurate current regulation.
• High Voltage: Be cautious when handling the VOUT pin, as it can output up to 220V.

The HV826MG_BACKLIGHT can be controlled using an Arduino UNO. Below is an example of how to enable and disable the driver using a digital pin.

• Connect the VIN pin to the Arduino's 5V output.
• Connect the GND pin to the Arduino's GND.
• Connect the EN pin to a digital pin on the Arduino (e.g., pin 7).
• Connect the LED string as described in the usage instructions.

// HV826MG_BACKLIGHT Control Example
// This code demonstrates how to enable and disable the HV826MG_BACKLIGHT
// using an Arduino UNO. The EN pin is connected to digital pin 7.

#define EN_PIN 7  // Define the Arduino pin connected to the EN pin of the driver

void setup() {
  pinMode(EN_PIN, OUTPUT);  // Set the EN pin as an output
  digitalWrite(EN_PIN, LOW);  // Start with the driver disabled
}

void loop() {
  digitalWrite(EN_PIN, HIGH);  // Enable the LED driver
  delay(1000);  // Keep the driver enabled for 1 second

  digitalWrite(EN_PIN, LOW);  // Disable the LED driver
  delay(1000);  // Keep the driver disabled for 1 second
}

1. Can the HV826MG_BACKLIGHT drive RGB LEDs?

   • Yes, but each color channel will require a separate driver circuit.

2. What is the maximum number of LEDs it can drive?

   • The number depends on the forward voltage of the LEDs and the total output voltage (up to 220V).

3. Can I use a PWM signal to dim the LEDs?

   • Yes, you can use a PWM signal on the EN pin to achieve dimming.

4. Is the HV826MG_BACKLIGHT suitable for battery-powered devices?

   • Yes, its low standby current (<1µA) makes it ideal for battery-powered applications.

5. What happens if the RSET resistor is not connected?

   • The driver may not regulate the current properly, leading to unpredictable behavior. Always connect an appropriate resistor to the RSET pin.