200W LED lighting system power supply designed with FAN6961

The general high-power LED lighting drive system can be realized by using LED drivers from TI, Intersil, ST, Richtek, Linear, and OnSemi. The key point is that the power output power required by LED street lights is generally greater than 100W, so designing a high-efficiency high-power power supply is the key point of the entire system. This article briefly introduces Fairchild Semiconductor's 200W power supply solution.

Fairchild's 200W power solution is mainly composed of a high power factor pre-regulator based on the FAN6961 voltage mode PFC controller and an isolated DC/DC converter based on a resonant LLC topology. The input voltage range can be from 90VRMS to 265VRMB, and it can generate six outputs with a maximum output power of 0.7A/48V per output.

FAN6961 is an 8-pin boundary mode PFC controller that can adjust the output DC voltage on time to achieve power factor correction. The device has a supply voltage of up to 25V, a starting current of less than 25uA, an operating current of less than 6mA, and can perform zero current detection and cycle-by-cycle current limiting. FAN6961 can be used in electronic lamp ballasts, AC/DC switching power converters, adapters, and flyback power converters with ZCS/ZVS. Figure 1 shows a circuit diagram with rectification and EMI filtering functions based on FAN6961.

Figure 1: Circuit diagram with rectification and EMI filtering functions based on FAN6961.

The FSFR2100 power switch is also an important element in this solution. The FSFR2100 uses zero voltage switching (ZVS) technology to significantly reduce the switching losses of the MOSFET and rectifier. With this technology, the switch can handle up to 200W of power without a heat sink, and up to 450W of power with a heat sink. The FSFR2100 also integrates all the necessary components to build a reliable and efficient resonant converter, and integrates a pulse frequency modulation (PFM) controller, a high-voltage gate drive circuit and two fast recovery MOSFETs (FRFETs) in a thermally efficient SiP package, as well as soft start, intermittent operation mode and important protection functions.

Figure 2: Prototype power solution for a 200W LED lighting system.

The detailed introduction and implementation circuit diagram of this 200W power solution can be found in the PDF document below. The main advantages of this power solution include: very compact design; full load efficiency greater than 94%; standby power consumption is only 1.2W; very low EMI; dimming can be achieved through PWM signal; only the PFC switch needs to add a heat sink.