A6983IQTR-STMicroelectronics-Price, Stock & Datasheet

The A6983I is a device specifically designed for isolated buck topology. The primary output voltage can be accurately adjusted, whereas the isolated secondary output is derived by using a given transformer ratio. No optocoupler is required. The primary sink capability up to -4.5 A (even during soft-start) allows a proper energy transfer to the secondary side, as well as enables a tracked soft-start of the secondary output. The control loop is based on a peak current mode architecture and the device operates in forced PWM. The 390 ns blanking time filters oscillations, generated by the transformer leakage inductance, makes the solution more robust.

Both the compact QFN-16 (3x3 mm) package and the internal compensation of the A6983I help minimizing the design complexity and size.

The switching frequency can be programmed in the 200 kHz to 1 MHz range with an optional spread spectrum for improved EMC.

The EN pin provides a enable/disable functionality. The typical shutdown current is 2 μA when disabled. As soon as the EN pin is pulled-up, the device is enabled and the internal 1.3 ms soft-start takes place. The A6983I features a Power Good open collector that monitors the FB voltage. Pulse by pulse current sensing on both power elements implements an effective constant current protection and thermal shutdown prevents thermal runaway.

Key features

AEC-Q100 qualified
Operating temperature range: -40 °C to +150 °C for T_j
Designed for iso-buck topology
3.5 V to 38 V operating input voltage
Load dump tolerant up to 40 V
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
25 μA operating quiescent current
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
Enable pin
Overvoltage protection
Output voltage sequencing
Thermal protection
Optional spread spectrum for improved EMC
Power Good
Synchronization to external clock
QFN16 (3x3 mm) package