Boost converter for LED backlight strings
The Texas Instruments TPS61061DRBRG4 is a fixed-frequency boost DC-DC regulator designed to drive LED backlight strings in small- to medium-size LCD panels. Dimming is controlled via a PWM signal on the dedicated dimming input, which modulates the LED current without shifting the output voltage — a standard approach for maintaining consistent colour temperature across the brightness range.
1 MHz switching — inductor and ripple trade-off
The 1 MHz oscillator lets the designer pick a small inductor, typically 4.7 µH to 10 µH in a 2.0 mm or 2.5 mm footprint, keeping the total solution height low for slim backlight assemblies. The trade-off is higher switching losses than a 500 kHz part, but the efficiency curve peaks in the 10 mA to 100 mA LED current range where most backlight strings operate.
Package and thermal land pattern
Without the vias, the junction temperature rises above the 85°C ambient ceiling at full load. The pad is electrically connected to GND, so the via pattern also serves as a low-impedance ground return for the switching loop.
It is not specified for under-hood or engine-bay environments where ambient exceeds 85°C.