Switching Power Supply

Before we get into the topic, let's have a brief look inside the switched mode cousin of the linear power supply. A switched mode power supply (SMPS) in the context of LED lighting refers to an LED driver that regulates the output to the LEDs through high-speed switching operation. The SMPS LED driver follows boost, buck, buck-boost or flyback circuit topologies to step up or step down supply voltage. One or more power transistor switches between on and off states at a given operating frequency to transform the incoming power supply into a pulsed current. The pulses of current are then smoothed using an energy storage component consisting of capacitors or inductors. There's minimal switching loss in modern switches such as a metal oxide using semiconductor en th abling effect ET transistor regulator to operate with high efficiency. However, high frequency switching can generate much noise and produce electromagnetic interference (EMI). The use of reactive component ts as well as the need for additional circuitry to suppress the switching noise makes switching regulators an expensive, bulky, unreliable and technically complex solution to LED load regulation.