SNVSAJ8D February 2016 – March 2018 LM36273
PRODUCTION DATA.
The high voltage required by the LED strings is generated with an asynchronous backlight boost converter. An adaptive voltage control loop automatically adjusts the output voltage based on the voltage over the LED drivers LED1, LED2 and LED3. The LM36273 has three switching frequency modes, 1 MHz, 500 kHz, and 250 kHz. These are set via the BL_FREQ Select bit, register 0x03 bit[7] and by utilizing the auto-frequency feature (refer toAuto Switching Frequency). Operation in low-frequency mode results in better efficiency at lighter load currents due to the decreased switching losses. Operation in high-frequency mode gives better efficiency at higher load currents due to the reduced inductor current ripple and the resulting lower conduction losses in the MOSFET and inductor.