Murata Releases Power Supply for LED Lamps
Murata has revealed a digital power supply module for LED lamps that the company says were developed for a Japanese LED lighting manufacturer, Clear Sodick, but it is also considering making the module available to other companies.
Murata used its MLCC for the input and output capacitors of the power supply module. The MLCC can be incorporated in a straight tube-type LED lamp. According to Murata, compared with an aluminum electrolytic capacitor, the MLCC can make a power supply module smaller and its life longer. The module supports the voltages of AC100V and AC200V.
Murata used a DSP microcontroller for constant current control of LED lamps. Its switching frequency is about 200kHz. Two MLCCs with a capacity of about 5µF are used as the output capacitors. The main circuit is a non-isolated buck-boost type and does not have a PFC circuit. The dimensions are 180 x 19.4 x 6.5mm.
As the DSP microcontroller, Murata employed Microchip Technology Inc.’s "dsPIC33F GS" and New Japan Radio Co Ltd.’s "NJU20010 (Alligator)."
The power supply module equipped with the dsPIC33F GS and the module with the NJU20010 have almost the same main circuit. But the latter module comes with two inductors for a larger output. Clear Sodick plans to use the two types of the modules for different applications.