DC/DC controller released in H- and MP-grade versions

5th August 2014

Siobhan O'Gorman

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Datasheet

H- and MP-grade versions of the LT8705 DC/DC controller has been released by manufacturer Linear Technology. The synchronous, buck-boost DC/DC controller operates over a 2.8-80V input voltage range and produces a fixed 1.3-80V output. Using a single inductor with 4-switch synchronous rectification, higher power can be achieved when multiple circuits are parallelled.

Four feedback loops regulate the input current/voltage, along with the output current/voltage. The input current and voltage feedback loops can prevent overloading of solar cells, while the output current loop provides a regulated output current for a battery charger or current source. The operating frequency is selectable between 100kHz and 400kHz, and can be synchronised to an external clock. For constant frequency operation in buck or boost mode, the LT8705 utilises a proprietary current-mode control architecture. As well as this, the user can select among forced continuous, discontinuous and Burst Mode operation to maximise light load efficiency.

Other features include servo pins to indicate which feedback loops are active, a 3.3V/12mA LDO, adjustable soft-start, onboard die temperature monitor and ±1.30% reference voltage accuracy over an operating junction temperature range of -55 to 150°C. The LT8705 is available in a 38-pin 5mm x 7mm QFN, and also a 38-lead TSSOP with additional pin spacing for high voltage operation. The H- and MP-grade versions are available over operating junction temperatures from -40 to 150°C and -55 to 150°C.