Linear Technology Corporation (Milpitas, CA) introduces the LTC3810H-5, a high input voltage synchronous step-down DC/DC controller with specifications for junction temperatures up to 150°C. The rugged controller can directly step down voltages from 60V to an output voltage ranging from 0.8V to 93% of VIN.
The device employs a constant on-time valley current-mode control architecture, delivering very low duty cycles and extremely fast transient response with accurate cycle-by-cycle current limit without requiring a sense resistor. The 1 Ohm onboard gate drivers minimize switching losses associated with driving N-channel MOSFETs at high frequency and high voltage for output currents up to 25A. Applications include 48V power conversion in telecom and datacom, as well as automotive and industrial systems susceptible to high surge voltages.
The LTC3810-5 features an adjustable minimum on-time that can be set as low as 100ns, enabling a high step-down ratio at high frequency. The operating frequency is selectable from 100kHz to 1MHz or can be synchronized to an external clock over the same range. Pulse skipping operation can be configured to maintain high efficiency at light loads. Additional features include programmable soft start or tracking, adjustable cycle-by-cycle current limit, output overvoltage protection, power good output signal and programmable undervoltage lockout.