The BJT devices must have a breakdown voltage higher then the high voltage on the high side MOSFET's. The driver will drive the gate of the high side MOSFET 10 vdc above the 315 vdc supply to ensure the high side Nch MOSFET is put into full conduction.Īttached is a schematic with a discrete high side MOSFET driver. The input logic goes to a current source drive to high side driver that has a high voltage breakdown limit so the high side driver section can ride 'up in the air' to the high side voltage (315v + 10v in your case). The IR2110 will not operate in a static drive condition (like fixed, full speed motor reversing). You must have switching periodically on the low side MOSFET to refresh the charge on the high side bootstrap cap. This give approximately 10 to 11 vdc charge (12v - diode drop - Vds ON of lowside MOSFET). When the applet starts up you will see an animated schematic of a simple LRC circuit. It is recharged every cycle when the low side MOSFET conducts on bottom side and through a diode that connects to the 12v supply on high side of cap. Figure 4 shows the supply voltage of the high side gate drivers. The power supply filter cap on this high side driver section drives the high side MOSFET driver circuitry. The L6205, L6206, L6207 are dual full bridge drivers ICs specifically developed to drive. Like in the hard-switched full bridge topology, the cdv/dt shoot-through current might produce a voltage spike at the gate of the off-state MOSFET on the same leg and cause devices failure. The upper high side driver in the IR2110 rides up and down the high voltage supply (315v).
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