VOUT_PGTH is a standard PMBus® command for setting or reading an 8-bit output voltage threshold at which Power Good (PGOOD) is be de-asserted. This command uses the PMBus® DIRECT format. When reading and writing to this register, use the coefficients shown in Table 8-67, Equation 19, and Equation 20 to convert between the real world units and hexadecimal values.

This command uses the PMBus® read or write word protocol.

Contents of this register are compared to the VOUT ADC telemetry value. Once the output voltage has fallen below the VOUT_PGTH threshold at any point of time during normal operation or the device detects a fault (except short-circuit), the PGOOD is de-asserted, and the PGOODB flags are set in the respective registers. The SMBA# signal is also asserted. 250 mV (typical) of hysteresis is added to the value in this register. In order for the PGOOD to be asserted again, the output voltage must rise above this rising threshold after clearing all underlying faults and enabling the FET internal to the device. However, the fault flags and alerts remain until cleared by the host by sending the CLEAR_FAULTS command.

When the output voltage is less than VOUT_PGTH threshold, the device:

• sets the NONE_OF_THE_ABOVE/UNKNOWN bit in the STATUS_BYTE register

• sets the PGOODB and NONE_OF_THE_ABOVE/UNKNOWN bits in the upper byte of the STATUS_WORD register

• sets the PGOODB bit in the STATUS_MFR_SPECIFIC_2 register

• notifies the host by asserting SMBA#, if it is not masked setting the PGOODB bit in the ALERT_MASK register and the GPIO4 pin is configured as SMBA# Output in the GPIO_CONFIG_34 register