The Texas Instruments LM5155 asynchronous boost controller provides a wide input range and uses peak current mode control. The device supports boost, SEPIC and flyback topologies. The characteristic of this device is that if the BIAS pin is connected to the V CC or DC pin, then a minimum of 2.97V with a single battery will start. pin. In addition, if the BIAS pin is greater than 3.5V, the controller can operate with an input supply voltage as low as 1.5V.
The controller has an internal V CC / sub. The regulator also supports BIAS pin operation up to 45V (absolute maximum 50V). The switching frequency can be dynamically programmed using external resistors from 100kHz to 2.2MHz. At 2.2MHz, interference in the AM band is reduced, resulting in a smaller solution size and fast transient response. This device supports 1.5A standard MOSFET driver and 100mV low current limit threshold. The use of an external VCC power source supported by the device improves efficiency.
Typical applications include multi-output flyback without optocoupler, LED bias power supply, wide input boost, flyback power module, portable speaker and battery-powered boost, SEPIC and flyback.