ZHCSIA7 May 2018 DLPA4000
PRODUCTION DATA.
Proper operation requires snubber networks. The switching frequency can vary from several hundreds of kHz to frequencies in the MHz range. To switch currents from zero to several amperes requires only nanoseconds, equivalent to even much higher frequencies. EMI can occur when ringing occurs on the edges. This ringing can have higher amplitude and frequency than the switching voltage. All DLP4000 buck converters require a snubber network to prevent ringing. The snubber network comprises a resistor and a capacitor in series.
Place an R-C snubber network (C32 and R56) to reduce ringing on the switching node. Place the capacitor on top of a large plane for the switching node directly next to the PGND plane. This resistor placement eliminates the gap between the switching node and the PGND plane used by the PowerBlocks.