Buck boost controller operates up to 150°C

Offering efficiencies up to 98%, the devices operate over a 2.8 to 80V input voltage range and produce a fixed 1.3 to 80V output, using a single inductor with 4-switch synchronous rectification. Output power up to 250W can be delivered with a single device. Higher power can be achieved when multiple circuits are paralleled. The H and MP grade versions are guaranteed over operating junction temperatures from -40 to 150°C and -55 to 150°C, respectively. The LT8705 has four feedback loops to regulate the input current/voltage, along with the output current/voltage. The input current and voltage feedback loops can prevent overloading of solar cells. The output current loop provides a regulated output current for a battery charger or current source. The operating frequency is selectable between 100 and 400kHz, and can be synchronised to an external clock. The LT8705 employs a proprietary current mode control architecture for constant frequency operation in buck or boost mode and has on board quad N channel MOSFET gate drivers. Users can select among forced continuous, discontinuous and Burst Mode operation to maximise light load efficiency.