Power stage

The board’s power stage consist of three N-channel MOSFET half-bridges (Q1 - Q6) and a DRV8305 pre-driver (U1). The power stage can be described as the components necessary to deliver the power to drive a brushless motor according to the logic from the logic stage. The area marked in red shows the power stage in the Dagor Controller - Alpha.

The DRV8305 is a three-phase gate driver that can drive high and low-side N-channel MOSFETs. What makes this driver special is the amount of programmable parameters, the protection features and the fault diagnostics; all of which take place through an SPI bus. The driver has two types of faults: warning and fault. If either occur the red indicator LED on the Dagor board will turn on; if a fault occurs the MOSFETs will be placed in their high impedance state, if a warning occurs operation will continue normally. A few of the faults that the driver reports are the following: high temperature flags, source under or over-voltage, VDS over current monitors, gate drive fault, etc. Please refer to the DRV8305 datasheet if you want to learn more about all the features of this driver IC. The picture below shows the simplified schematic of the whole power stage (driver + MOSFETs).