ON Semiconductor FSL306LR integrated pulse width modulator (PWM) and SenseFET is specifically designed for high-performance offline buck, buck-boost, and non-isolation flyback switched mode power supplies (SMPS) with minimal external components. The FSL306LR can be configured to power IoT applications where a non-isolated AC/DC power solution is needed to provide power for devices such as sensors, RF transceivers, and microprocessors. The FSL306LR's features include a monolithic power solution with a 650 V rugged MOSFET, an adjustable peak current limit that offers optimum output power inductor designs, and a cycle-by-cycle current limit providing solid over-power protection. Self-biasing removes the need for auxiliary power and enables a compact power solution. Very low operating currents also relieve package thermal stress, improving reliability. The built-in, high-voltage soft-start is ideal for space-constrained applications.

The integrated PWM controller includes a 10 V regulator for no external bias circuit, undervoltage lockout (UVLO), leading-edge blanking (LEB), an optimized gate turn-on / turn-off driver, EMI attenuator, thermal shutdown (TSD), temperature-compensated precision current sources for loop compensation, and fault-protection circuitry. Protections include overload protection (OLP), overvoltage protection (OVP), feedback open-loop protection (FB_OLP), and abnormal overcurrent protection (AOCP). The FSL306LRN offers good soft-start performance during startup.

The internal high-voltage startup switch and the burst-mode operation with very low operating current reduce the power loss in standby mode. As a result, it is possible to reach power loss of 120 mW without external bias and 25 mW with external bias when input voltage is 230 V_AC.