Synchronous Step-Down Controller

July 20, 2017

Jennifer Shuttleworth

The LTC7800 from Analog Devices, Inc. (Norwood, MA), which recently acquired Linear Technology Corp., is a synchronous step-down DC/DC controller that operates at up to 2.25 MHz for reduced circuit size and increased power density. Its low 45 ns minimum on-time enables 24-V_IN to 3.3-V_OUT conversions while switching at a fixed 2 MHz, avoiding critical noise-sensitive frequency bands including AM radio. Synchronous rectification delivers up to 95% efficiency while Burst Mode operation keeps quiescent current under 50 μA in no-load standby conditions, suitable for always-on systems. The output voltage can be set from 0.8 V to 24 V at output currents up to 20 A, which is well suited for 12-V or 24-V automotive, heavy equipment, industrial control, robotics and telecom applications.