STMicroelectronics L5991 Manuals

L5991 L5991A is a primary controller with standby current-mode control PWM switching frequency up to 1MHz, low start-up current (<120µA), high-current output drive suitable for power MOSFET (1A), fully latched PWM logic with double pulse suppression, programmable duty cycle 100% and 50%, maximum duty cycle limit, standby function, programmable soft start, primary overcurrent fault detection with re-start delay, PWM UVLO with hysteresis, internal 100ns leading edge blanking of current sense, DIP16 and SO16 package.

This document describes a 55W flyback SMPS demonstration board for an alarm system, based on L5991 and STP12NK80Z. It features multiple output voltages and signals, as well as a battery charger circuit. The input voltage range is 88-300Vac, and the output voltages include 13.8V, 25V, and 3.8V.

The STEVAL-ISA032V1 is a 60 W forward converter demonstration board for fiscal cash register based on the L5991 and STP10NK60Z.