SLVSD12D May 2015 – July 2019 DRV8305-Q1
PRODUCTION DATA.
The DRV8305-Q1 uses a multilevel scheme to protect the external MOSFET from VGS voltages that could damage it. The first stage uses integrated VGS clamps that will turn on when the GHx voltage exceeds the SHx voltage by a value that could be damaging to the external MOSFETs.
The second stage relies on the TDRIVE state machine to detect when abnormal conditions are present on the gate driver outputs. After the TDRIVE timer has expired the gate driver performs a check of the gate driver outputs against the commanded input. If the two do not match a gate drive fault (FETXX_VGS) is reported. This can be used to detected gate short to ground or gate short to supply event. The TDRIVE timer is adjustable for the high-side and low-side gate drive outputs through the TDRIVEN setting in register 0x5, bits D9-D8 and the TDRIVEP setting in register 0x6, bits D9-D8. The gate fault detection through TDRIVE can be disabled through the DIS_GDRV_FAULT setting in register 0x9, bit D8.
The third stage uses undervoltage monitors for the low-side gate drive regulator (VCP_LSD_UVLO2) and high-side gate drive charge pump (VCPH_UVLO2) and an overvoltage monitor for high-side charge pump (VCPH_OVLO). These monitors are used to detect if any of the power supplies to the gate drivers have encountered an abnormal condition.