SLVSH22 May 2024 DRV8000-Q1
ADVANCE INFORMATION
By default, the PDR loop automatically detects which MOSFET is the drive MOSFET and which MOSFET is the freewheel MOSFET by determining the polarity of the current out of the half-bridge. This is done by measuring the half-bridge VSHx voltage during the dead-time period to determine if the high-side or low-side body diode is conducting. If the current polarity cannot be determined it is assumed that the configured MOSFET through IDIR_MAN_SEL is the drive MOSFET. The automatic freewheel detection can be disabled with the IDIR_MAN bit in register GD_AGD_CNFG. In the manual freewheel modes, the PDR loop relies on the IDIR_MAN_SEL bit in register GD_STC_CNFG to determine which MOSFET is the drive MOSFET and which MOSFET is the freewheel MOSFET. If IDIR_MAN_SEL = 0b, the high-side MOSFET is the drive MOSFET and the low-side MOSFET is the freewheel MOSFET. If IDIR_MAN_SEL = 1b, the low-side MOSFET is the drive MOSFET and high-side MOSFET is the freewheel MOSFET.
HS Drive PWM Turn On/Off Example shows the high-side MOSFET (HS1) controlling the VSHx switch-node voltage transition and the low-side MOSFET (LS1) acting as the freewheeling MOSFET.
LS Drive PWM Turn On/Off Example shows the low-side MOSFET (LS2) controlling the VSHx switch-node voltage transition and the high-side MOSFET (HS2) acting as the freewheeling MOSFET.