MP-grade DC/DC controller for battery-powered apps

Linear Technology has announced a high-reliability (MP) grade version of the LT3845 synchronous step-down DC/DC controller, which can be used in battery-powered applications.

The controller has a 4 to 60V input voltage range and low quiescent current, with Burst Mode operation to keep quiescent current under 120uA in no-load standby conditions.

The device's onboard N-channel MOSFET gate drivers provide output current up to 20A at efficiencies as high as 95 per cent, making it suitable for 12 and 24V automotive systems, industrial controls, heavy equipment, avionics and military systems.

The LT3845 can produce an output voltage from 1.23 to 36V.

The switching frequency is programmable from 100 to 500kHz or can be synchronised to an external clock up to 600kHz.

Current-mode control provides fast-line and load-transient response, as well as cycle-by-cycle overcurrent protection.

The onboard regulator provides IC power directly from the input supply, without the need for a separate bias voltage.

Other features include short-circuit protection, adjustable soft start, thermal shutdown and precision input undervoltage lockout.

The LT3845 employs adaptive non-overlap control, which maintains a constant dead time, preventing shoot-through switch currents, independent of the type, size or operating conditions of the external MOSFET switches.

The LT3845MP operates and is 100 per cent tested over a junction temperature range of -55 to 125C, compared with the I grade version's -40 to 125C operating temperature range.

It is offered in a 16-lead thermally enhanced TSSOP package.

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