Overview
The LM36274YFFR from Texas Instruments is an integrated four-channel white LED (WLED) driver and LCD bias supply. This component is designed for high efficiency and programmability, making it suitable for a variety of applications. It features a compact 24-pin DSBGA package, measuring 2.44 mm × 1.67 mm, and operates within a wide input voltage range of 2.7 V to 5 V. The device supports both PWM and I2C brightness control, offering flexible dimming options. It is particularly useful in applications requiring backlighting and LCD bias voltage management.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Input Voltage (VIN) | 2.7 | - | 5 | V |
| Operating Ambient Temperature (TA) | -40 | - | 85 | °C |
| Maximum Output Current (per string) | - | - | 30 | mA |
| LED Current Accuracy | -3% | - | 3% | % |
| LED Current Matching | -2% | - | 0.2% | % |
| Switching Frequency | 450 | 500 | 550 | kHz (500-kHz mode) |
| Switching Frequency | 900 | 1000 | 1100 | kHz (1-MHz mode) |
| Thermal Shutdown | - | - | 140 | °C |
| Junction-to-Ambient Thermal Resistance | - | - | 63.1 | °C/W |
Key Features
- Drives up to four parallel white LED strings with a maximum VOUT of 29 V.
- 11-bit exponential and linear dimming control.
- PWM and I2C brightness control.
- Backlight operation with 4.7-µH to 15-µH inductor.
- Backlight and LCD bias efficiency up to 92%.
- Programmable LCD bias voltages (±4 V to ±6.5 V with 50-mV resolution) with up to 80-mA per output.
- 0.2% matched LED current from 60 µA to 30 mA.
- 1% accurate LED current from 60 µA to 30 mA.
Applications
- LCD panels with up to 24 LEDs.
- Smartphones.
- Tablets and gaming tablets.
- Home automation panels.
Q & A
- What is the input voltage range of the LM36274YFFR?
The input voltage range is from 2.7 V to 5 V. - What is the maximum output current per LED string?
The maximum output current per LED string is 30 mA. - What are the dimming control options available?
The device supports both PWM and I2C brightness control. - What is the efficiency of the backlight and LCD bias?
The efficiency of the backlight and LCD bias can be up to 92%. - What is the range of programmable LCD bias voltages?
The programmable LCD bias voltages range from ±4 V to ±6.5 V with 50-mV resolution. - What is the thermal shutdown temperature?
The thermal shutdown temperature is 140°C. - What is the junction-to-ambient thermal resistance?
The junction-to-ambient thermal resistance is 63.1°C/W. - What types of devices can the LM36274YFFR be used in?
The LM36274YFFR can be used in smartphones, tablets, gaming tablets, and home automation panels. - How many LED strings can the LM36274YFFR drive?
The LM36274YFFR can drive up to four parallel white LED strings. - What is the resolution of the LED current matching?
The LED current matching has a resolution of 0.2% from 60 µA to 30 mA.
