TFT LCD bias supply – four-rail generator
The TPS65124RGTT: The fourth output is a regulated low-dropout rail that can supply the logic or interface voltage. This part is a single-chip alternative to discrete boost converter plus charge-pump pairs, saving board space and reducing component count on the display power chain.
Housed in a 16-VFQFN with exposed pad (3 mm × 3 mm body), the TPS65124RGTT lands on a 16-VQFN footprint. Without that thermal path, the junction temperature rises quickly under load, especially when the charge-pump rails are delivering current. The QFN package is reworkable with hot air if you preheat the board to 120 °C and use a nozzle that covers the body without blasting the adjacent passives.
Temperature range and application environment
The 85 °C ceiling means the part cannot be placed near a hot backlight driver without thermal margin analysis; if the ambient inside the enclosure hits 70 °C, the derating on the charge-pump output current starts to bite.