Texas Instruments LM36923H Triple-String White LED Driver
Texas Instruments LM36923H Triple-String White LED Driver is an ultra-compact, highly efficient, three-string white-LED driver, designed for LCD display backlighting. The device can power up to 12 series LEDs at up to 25mA per string. An adaptive current regulation method allows for different LED voltages in each string while maintaining current regulation. The LED current is adjusted via an I2C interface or through a logic-level PWM input. The PWM duty cycle of the Texas Instruments LM36923H is internally sensed and mapped to an 11-bit current. This feature allows for a wide range of PWM frequencies with noise-free operation from 50µA to 25mA. Other features include an auto-frequency mode, which can automatically change the frequency based on load current to optimize efficiency.
Features
- 1% matched current sinks across process, voltage, temperature
- 3% current-sink accuracy across process, voltage, temperature
- 11-bit dimming resolution
- Up to 90% solution efficiency
- Drives from one to three parallel LED strings at up to 38V at 25mA per string
- PWM dimming input
- I2C programmable
- Selectable 500kHz and 1MHz switching frequency with optional –12% shift
- Auto switch frequency mode (250kHz, 500kHz, 1MHz)
- Four configurable overvoltage protection thresholds (17V, 24V, 31V, 38V)
- Four configurable overcurrent protection thresholds (750mA, 1000mA, 1250mA, 1500mA)
- Thermal shutdown protection
- Externally selectable I2C address options via ASEL input
Applications
- Power source for smartphone and tablet backlighting
- LCD panels with up to 24 LEDs
Simplified Schematic
Related Development Tool
Texas Instruments LM36923HEVM White LED Driver Evaluation Module
Fully evaluate the LM36923H, a highly efficient triple-string white LED backlight driver.
Opublikowano: 2016-05-04
| Zaktualizowano: 2022-03-11