L6983I Converter: Flexible Isolated-Buck IC for Protected Power Conversion and Gate Driving in IGBTs, SiC, and GaN Transistors

STMicroelectronics has launched the new L6983i 10W isolated buck (iso-buck) converter that ensures high efficiency and a compact footprint, with advantages including low quiescent current and 3.5V-38V input-voltage range. It implements an iso-buck topology, which uses fewer components than a conventional isolated flyback converter and requires no optocoupler, saving bill-of-materials costs and PCB space. It can be used to power isolated gate drivers for IGBTs and silicon-carbide (SiC) or gallium-nitride (GaN) transistors, industrial automation, small traction systems and charging stations, and isolated safety equipment.

Capable of sourcing/sinking up to 4.5A primary current, the L6983i allows the switching frequency to be adjusted from 200kHz to 1MHz and to be also externally synchronized. Further benefits of the L6983i include 2µA shutdown current and integrated functions such as adjustable soft-start time, internal loop compensation and power good indicator, as well as protection from overcurrent and thermal shutdown. The selectable spread-spectrum feature improves EMC performance.

Features

• 3.5 to 38V operating input voltage

• Primary output voltage regulation / no optocoupler required

• 200 kHz to 1 MHz programmable switching frequency

• Stable with low ESR capacitor (min. 2 µF)

• Internal compensation network

• 2 µA shutdown current

• Internal soft-start

• Overvoltage protection

• Output voltage sequencing

Applications

• Isolated IGBT/SiC MOSFET gate drive supply

• OBC (On-board charger) for HEV/EV

• Electric traction systems

Availability & Pricing

The L6983i iso-buck converter is in production now, in a 3mm x 3mm QFN16 package, and is available from $1.38 for orders of 1000 pieces.