Datasheet

WPMDL110xxx1S / 17301xx78

MagI

C Power Module

FDSM – Fixed Step Down Regulator Module

We-online.com Würth Elektronik eiSos GmbH & Co. KG – Data Sheet Rev. 1.0

BLOCK DIAGRAM

CIRCUIT DESCRIPTION

The MagI³C Power Module 173xxxx78 is based on a non-synchronous step-down regulator with integrated MOSFET, free-

wheeling diode, power inductor, input and output capacitors. The control scheme is based on a Current Mode (CM)

regulation loop.

The V

OUT

of the regulator is divided with the internal feedback resistor network and fed into the error amplifier which

compares this signal with the internal 0.8V reference. The error signal is amplified and controls the on-time of a fixed

frequency pulse width generator. This signal drives the power MOSFET.

The Current Mode architecture features a constant frequency during load steps. Only the on-time is modulated. It is

internally compensated and stable with low ESR output capacitors and requires no external compensation network.