Non-synchronous boost controllers offer a small solution size

17-06-2019 | Texas Instruments | Power

Texas Instruments LM5155 Non-Synchronous Boost Controllers provide a broad input range and uses peak current mode control. The device enables boost, SEPIC, and flyback topologies. Featured for the device, is a 1-cell battery startup with a minimum of 2.97V if the BIAS pin is connected to the V<sub>CC</sub> pin. Furthermore, the controllers can work with the input supply voltage as low as 1.5V if the BIAS pin is greater than 3.5V.

The controllers have an internal V<sub>CC</sub> regulator also supporting BIAS pin operation up to 45V (50V absolute max). The switching frequency is dynamically programmable with an external resistor from 100kHz to 2.2MHz. At 2.2MHz AM band interference is decreased, producing a small solution size and fast transient response. The device supports a 1.5A standard MOSFET driver and a low 100mV current limit threshold. The utilisation of an external VCC supply, supported by the device increases efficiency.

Typical applications include multiple-output flyback without optocoupler, LED bias supplies, wide input boost, flyback power modules, portable speakers, and battery-powered boosts, SEPIC, and flybacks.

By Natasha Shek