With compensation circuitry on-chip, these highly integrated monolithic devices need only minimal external components including filtering, feedback, and a transformer with the A6983I.
STMicroelectronics has introduced new automotive-qualified step-down synchronous DC/DC converters that save space and ease integration in applications including body electronics, audio systems, and inverter gate drivers. The A6983 converters offer flexible design choices, comprising six non-isolated step-down converters in low-consumption and low-noise configurations and the A6983I isolated buck converter.
The non-isolated A6983 converters can supply up to 3A load current and achieve 88% typical efficiency at full load. The low-consumption variants (A6983C) are optimized for light-load operation, with high efficiency and low output ripple, to minimize drain on the vehicle battery in applications that remain active when parked. The low-noise A6983N variants operate with constant switching frequency and minimize output ripple across the load range for optimum performance in applications such as audio-system power supplies. Both types offer a choice of 3.3V, 5.0V, and adjustable output voltage from 0.85V to VIN.
The A6983I is a 10W iso-buck converter with primary-side regulation that eliminates the need for an optocoupler. Ideal for use as an isolated gate driver for IGBTs or silicon-carbide (SiC) MOSFETs in traction inverters and on-board chargers (OBCs), this converter allows accurate adjustment of the primary output voltage. The transformer turns ratio determines the secondary voltage.
The converters are offered in a 3mm x 3mm QFN16 package. Pricing starts at $1.75 for the A6983 and $1.81 for the A6983I, for orders of 1000 pieces, and free samples of the A6983 and A6983I are available from the ST eStore. The STEVAL-A6983CV1 and STEVAL-A6983NV1 A6983 evaluation boards and STEVAL-L6983IV for the A6983I are available to kickstart development and accelerate project completion.
