The LT1942 is a highly integrated quad switching regulator designed to provide all necessary power supply functions for TFT displays, including the white LED backlight driver. The TFT supply incorporates two boost and one inverting DC/DC converters. The TFT supply output voltages are independently set, unlike charge pump solutions which have many limitations. Power sequencing for the TFT supply is built into the part and is user programmable. The LED driver is a boost DC/DC converter that can be independently controlled. The LED driver has built-in dimming control for precise control of LED current. An 8:1 dimming range is achieved by adjusting the CTRL4 voltage.The user can elect to drive a single string or two strings of LEDs. An LED ballast circuit is included to precisely match the LED currents if two strings of LEDs are used. Soft-start is built into the LED driver as well as the primary TFT supply. The LT1942 is available in a low profile (0.75mm) 24-lead QFN (4mm × 4mm) package.
The LT1942 is a highly integrated quad switching regulator designed for TFT display power supplies and white LED backlight drivers. It includes two boost converters and one inverting DC/DC converter for the TFT supply, plus a separate boost converter with built‑in dimming for the LED driver.
The device is supplied in a low‑profile 24‑lead plastic QFN (4 mm × 4 mm) package and supports an input voltage range of 2.6 V to 16 V, with a fixed switching frequency of 0.8‑1.2 MHz. It provides programmable power‑good signals, soft‑start, and LED current matching features.
| Input Voltage Range | 2.6 V to 16 V |
|---|---|
| Switching Frequency | 0.8 MHz – 1.2 MHz |
| Package | 24‑Lead QFN (4 mm × 4 mm) |
The LT1942 operates with an input voltage from 2.6 V up to 16 V.
The LT1942 is a quad device, containing four independent switching regulators.
It is supplied in a 24‑lead plastic QFN package measuring 4 mm × 4 mm.