Diodes Incorporated has introduced a series of synchronous buck converters for low output voltage power regulation in digital TV, monitor and other high density, fast changing point-of-load system architectures. Employing adaptive constant on-time (AdCOT) control, the AP65450, AP65452 and AP65552 ensure high DC output accuracy, high efficiency and fast transient response.
For the 4A rated AP65450 converter, the AdCOT control supports seamless transition between a continuous conduction mode (CCM) at high loads to a discontinuous conduction mode (DCM) at light loads. The 4A AP65452 and 5A AP65552 variants are designed to remain in CCM to help achieve better system noise reduction and filtering.
Up to 92% efficient and with the added option of automatic light loading to further improve performance, the converters help to simplify compliance with regional low power consumption regulations. In addition, their wide, 4.5V to 18V, operating voltage range will suit 5V, 9V and 12V bus systems.
The devices’ high switching frequency of 650kHz – fixed for the AP65452 and AP65552, variable for the AP65450 under low load conditions – combined with the AdCOT control, enables designers to achieve good output stability while shrinking PCB size, through the use of fewer and smaller external inductive and capacitive components. To help save more space, the three devices are provided in the compact SO-8EP package.
To protect downstream components from damage and premature aging, the buck converters incorporate a wide range of protection features including, under voltage lockout, thermal shutdown and over current protection.