New asynchronous buck converters from Diodes Incorporated
Diodes Incorporated have introduced four new automotive-compliant asynchronous buck converters for 48V low-voltage rail point-of-load (PoL) applications
The AP68255Q/AP68355Q and AP6A255Q/AP6A355Q use 500mΩ power MOSFETs to provide high-efficiency step-down DC-DC conversion with a continuous output current of up to 3.5A.
The new buck converters cover the full automotive battery range from 5.5V to 80V/100V, including dump scenarios. They can be used in multiple applications such as 48V motor control, advanced driver assistance systems (ADAS), telematics, infotainment, body control, instrument clusters, and lighting systems.
Constant on-time (COT) control is employed by the converter to maintain an almost constant switching frequency of 300kHz. This results in quick load/line transient response, easy loop stabilisation, and low output voltage ripple to make the device easier to incorporate, needing fewer external components.
The propriety gate-driver arrangement in the devices helps to reduce switch node ringing effects without sacrificing the turn-on and turn-off times of the N-channel MOSFET switch. By using this method, the high-frequency radiated electromagnetic interference (EMI) noise associated with MOSFET switching is reduced.
The built-in overcurrent protection (OCP) with frequency foldback mode enables high load-current support while reducing junction temperature under fault conditions. The controller's output voltage is immediately shut down at 160°C by the overtemperature protection (OTP), and when it drops below the 140°C safety threshold, the converter automatically restarts.
The AP68255Q/355Q and AP6A255Q/355Q asynchronous buck converters are available in the thermally enhanced SO-8EP package with an operating temperature range of -40°C to +125°C.