ST STEVAL-L6983IV1 User Manual

Getting started with STEVAL-L6983IV1 evaluation board based on L6983I, 38V,
Introduction
The STEVAL-L6983IV1 evaluation board is based on the L6983I, 38 V, 10 W synchronous iso-buck converter designed for
isolated applications.
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 -4.5A (even during soft-start) allows transferring
a proper energy to the secondary side as well as enabling 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, making the solution more robust.
The compact QFN-16 3x3mm package and the internal compensation of the
size.
The switching frequency can be programmed in the 200 kHz - 1 MHz range with an optional spread spectrum for improved
EMC.
The EN pin provides the 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 L6983I features the power good open collector that monitors the FB voltage. Pulse by pulse, the current sensing on both
power elements implements an effective constant current protection. The thermal shutdown prevents thermal run-away. Due to
the primary reverse current limit, the secondary output is protected against short-circuit events.
The evaluation board generates an isolated unregulated voltage and provides the possibility to use a post-regulation to generate
a dual voltage (layout available on the bottom of the PCB, components not mounted).
UM3110 - Rev 1 - March 2023
For further information contact your local STMicroelectronics sales office.
10W synchronous iso-buck converter for isolated applications
Figure 1. STEVAL-L6983IV1 evaluation board
L6983I help minimize the design complexity and
UM3110
User manual
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