SLVSE65C July 2018 – December 2023 DRV8847
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
In this operating mode, all the FETs of the full-bridges are in the high impedance (Hi-Z) state. The motor also goes to the Hi-Z state, and the motor starts coasting. This operating mode also helps to decay the motor current faster and is therefore also referred to as a fast decay mode. If the motor was initially connected in forward operation (current flows from terminal A to terminal B) and if the coast operation is applied, then, because of the inductive nature of the motor load, the current continues to flow in the same direction (A to B), and the anti-parallel diodes of the alternate FETs start conducting as shown in Figure 7-6. This flow of current through anti-parallel diodes lets the current decrease rapidly because of the higher negative potential created by the supply voltage, VM.