SLUSCC7C July 2016 – June 2018 TPS546C23
The PCT_OV_UV_WRN_FLT_LIMITS command is used to set the PGOOD, VOUT_UNDER_VOLTAGE (UV) and VOUT_OVER_VOLTAGE (OV) limits as a percentage of nominal.
For loop slave device, this command cannot be accessed. Any writes to this command will be ignored. An attempt to read or write this command will result in a NACK’d command, the reporting of an IVC fault, and triggering of SMB_ALERT.
The PCT_OV_UV_WRN_FLT_LIMITS takes a one byte data formatted as shown below:
The PGOOD, VOUT_UNDER_VOLTAGE (UV) and VOUT_OVER_VOLTAGE (OV) settings are shown in Table 13, as a percentage of nominal reference voltage on the FB pin.
|PCT_MSB||PCT_LSB||UV FAULT||UV WARN||OV WARN||OV FAULT||UNIT|
The PGOOD pin may trip if the output voltage is too high (using OV WARN) or too low (using UV WARN). Additionally, the PGOOD pin has hysteresis. When the OV WARN output voltage OV WARN is tripped, the FB voltage must lower below the 105% of EA_REF, before PGOOD is reset. Likewise, when output voltage UV WARN is tripped, the FB voltage must rise above 95% of EA_REF, before PGOOD is reset.