Linear Technology Corporation has introduced the LTC3824, an adjustable switching frequency dc/dc current mode controller well-suited for automotive applications where its 4 V minimum input voltage supports cold cranking and its 60 V maximum input voltage survives inductive load dumps, without the need for external clamping circuits.
The LTC3824 can be configured for burst mode operation, which can improve light load efficiency especially during system standby, where quiescent current is reduced to 40 µA. Typical shutdown current is 25 µA. The device drives an external P-channel MOSFET and can operate at 100% duty cycle for very low dropout voltage (VOUT approaching VIN). Its current mode architecture is said to provide fast line and load transient response as well as cycle-by-cycle overcurrent protection. Additional features include short-circuit protection, adjustable soft-start and overvoltage protection.
The LTC3824 can be programmed to a fixed frequency from 100 kHz to 600 kHz or for noise sensitive requirements, and can be synchronized to an external clock over the same range. Its output voltage can be adjusted over a wide range from 0.8 V to VIN. The LTC3824 is packaged in a 10-pin, thermally enhanced MSOP. The LTC3824EMSE operates from -40 °C to 85 °C and the LTC3824IMSE from -40 °C to 125 °C.