Description：

The L6983I is a device specifically designed for isolated buck topology. The primaryoutput voltage can be accurately adjusted, whereas the isolated secondary output isderived by using a given transformer ratio. No optocoupler is required. The primarysink capability up to -4.5 A (even during soft-start) allows a proper energy transferto the secondary side as well as enabling a tracked soft-start of the secondaryoutput. The control loop is based on a peak current mode architecture and the deviceoperates in forced PWM. The 390 ns blanking time filters oscillations, generated bythe transformer leakage inductance, making the solution more robust.The compact QFN16 3x3 mm package and the internal compensation of the L6983Ihelp minimize design complexity and size.The switching frequency can be programmed in the 200 kHz - 1 MHz range withoptional spread spectrum for improved EMC. The EN pin provides enable/disablefunctionality.The typical shutdown current is 2 μA when disabled. As soon as the EN pin is pulledup the device is enabled and the internal 1.3 ms soft-start takes place. The L6983Ifeatures Power Good open collector that monitors the FB voltage. Pulse by pulsecurrent sensing on both power elements implements an effective constant currentprotection and thermal shutdown prevents thermal run-away.

Features：

• Designed for iso-buck topology

• 3.5 V to 38 V operating input voltage

• Primary output voltage regulation / no optocoupler required

• 4.5 A source / sink peak primary current capability

• Peak current mode architecture in forced PWM operation

• 390 ns blanking time

• 200 kHz to 1 MHz programmable switching frequency. Stable with low ESRcapacitor: min 2 µF

• Internal compensation network

• 2 μA shutdown current

• Internal soft-start

• Enable

• Overvoltage protection

• Output voltage sequencing

• Thermal protection

• Optional spread spectrum for improved EMC

• Power Good

• Synchronization to external clock

• QFN16 (3x3 mm) package

Applications：

• Isolated IGBT/SiC MOSFET gate drive supply

• OBC (On-board charger) for HEV/EV

• Electric traction systems