How to Use HV826MG_BACKLIGHT: Examples, Pinouts, and Specs

The HV826MG_BACKLIGHT is a high-voltage boost converter optimized for driving white LED backlights in LCD panels. It is capable of converting a low-voltage input into a high-voltage output necessary for illuminating the backlight. Due to its efficiency and compact form factor, the HV826MG_BACKLIGHT is particularly suitable for use in portable electronic devices where space and power consumption are critical considerations.

• Laptop and notebook computers
• Portable media players
• Handheld gaming devices
• GPS units
• Other devices with LCD screens requiring backlighting

• Input Voltage Range: 2.4V to 5.5V
• Output Voltage Range: Up to 28V
• Maximum Output Current: 30mA
• Switching Frequency: 1.2MHz
• Efficiency: Up to 85%
• Operating Temperature Range: -40°C to +85°C

1. Power Supply Connection: Connect a power source within the specified input voltage range to the VIN pin and connect the GND pin to the system ground.
2. Inductor Selection: Choose an appropriate inductor value as per the datasheet recommendations and connect it between the SW and LX pins.
3. Output Capacitor: Connect an output capacitor between the LX pin and GND to stabilize the output voltage.
4. Feedback Network: Create a voltage divider using two resistors connected between the LX pin, FB pin, and GND to set the desired output voltage.
5. Enable Pin: Control the operation of the HV826MG_BACKLIGHT by applying a logic high or low signal to the EN pin.

• Ensure that the input voltage does not exceed the maximum rating to prevent damage to the device.
• Use ceramic capacitors with low equivalent series resistance (ESR) for better performance.
• Place the inductor and capacitors as close to the device as possible to minimize losses and noise.
• Avoid long traces on the PCB to reduce electromagnetic interference (EMI).
• Implement proper thermal management if the device is expected to operate at high ambient temperatures or output currents.

• Insufficient Brightness: Check if the output voltage is within the specified range and adjust the feedback network if necessary.
• Device Overheating: Ensure that the input voltage is within limits and that the thermal management is adequate.
• Intermittent Operation: Verify that the EN pin is receiving a stable logic signal and that there are no loose connections in the circuit.

• If the output voltage is too low, re-evaluate the resistor values in the feedback network.
• For overheating issues, consider adding a heatsink or improving airflow around the device.
• Ensure that the power supply can provide sufficient current for the startup and operation of the boost converter.

Q: Can the HV826MG_BACKLIGHT drive multiple LEDs in series? A: Yes, as long as the total forward voltage of the LEDs does not exceed the maximum output voltage of the device.

Q: Is it possible to adjust the output voltage? A: Yes, the output voltage can be adjusted by changing the resistor values in the feedback network.

Q: What is the maximum number of LEDs that can be driven by this device? A: The maximum number is determined by the forward voltage of the LEDs and the maximum output current of the HV826MG_BACKLIGHT. Ensure the total forward voltage and current do not exceed the specifications.

Q: How do I enable or disable the HV826MG_BACKLIGHT? A: Apply a logic high signal to the EN pin to enable the device, and a logic low signal to disable it.

Q: What should I do if the device is not starting up? A: Check the connections to the VIN, GND, and EN pins for proper voltage levels and signal integrity. Also, verify the inductor and capacitor values and placements.

// Define the Arduino pin connected to the HV826MG_BACKLIGHT's EN pin
#define ENABLE_PIN 7

void setup() {
  pinMode(ENABLE_PIN, OUTPUT);
  // Start with the backlight disabled
  digitalWrite(ENABLE_PIN, LOW);
}

void loop() {
  // Enable the HV826MG_BACKLIGHT
  digitalWrite(ENABLE_PIN, HIGH);
  delay(5000); // Keep the backlight on for 5 seconds

  // Disable the HV826MG_BACKLIGHT
  digitalWrite(ENABLE_PIN, LOW);
  delay(5000); // Keep the backlight off for 5 seconds
}

Note: This example assumes that the HV826MG_BACKLIGHT is properly connected to the Arduino UNO with the EN pin connected to digital pin 7. The code toggles the backlight on and off every 5 seconds. Ensure that the Arduino's output voltage is compatible with the HV826MG_BACKLIGHT's input voltage requirements.