The LTC3375’s pushbutton ON/OFF/RESET control, power-on reset and watchdog timer provide flexible and reliable power-up sequencing and system monitoring. All buck output voltages can be adjusted via I²C for margining or power optimization. The LTC3375 features a programmable and synchronizable 1MHz to 3MHz oscillator with a 2MHz default switching frequency. The device also contains a high voltage input shunt regulator controller, and quiescent current is only 11µA with all DC/DCs off. It is ideal for a wide variety of multichannel applications including automotive and communications systems.
Adjacent buck regulators can be combined in a master/slave configuration by connecting their VIN and SW pins together, and connecting the slave bucks’ FB pin(s) to the input supply. The switching regulators offer two operating modes: Burst Mode® operation (power-up default mode) for higher efficiency at light loads, and forced continuous PWM mode for lower noise at light loads. The I²C interface can be used to select mode of operation, phasing, feedback regulation voltage and switch slew rate. The bucks have forward and reverse current limiting, soft-start to limit inrush current during start-up, short-circuit protection and slew rate control for lower radiated EMI. Other features include a die temperature monitor output (readable via I²C or the analog voltage on the TEMP pin), which indicates internal die temperature and an overtemperature (OT) warning function, indicating high die temperature.
The LTC3375 is available from stock in a thermally enhanced, low profile (0.75mm) 48-pin 7mm x 7mm exposed pad QFN package. E and I grades are specified over an operating junction temperature range of -40°C to +125°C, and the H grade features operation from -40°C to +150°C. 1000-piece pricing starts at $5.45 each for the E grade.