7.6.20 VOUT_OV_FAULT_RESPONSE (41h) The VOUT_OV_FAULT_RESPONSE command instructs the device on what action to take in response to an Output Over Voltage Fault based on MFR_SPECIFIC_07 (PCT_OV_UV_WRN_FLT_LIMITS). The device also: • Sets the OVF bit in the STATUS_BYTE • Sets the VFW bit in the STATUS_WORD • Sets the OVF bit in the STATUS_VOUT register, and • Notifies the host by asserting SMBALERT 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 contents of this register can be stored to nonvolatile memory using the STORE_DEFAULT_ALL command
7.6.1 OPERATION (01h) The OPERATION command turns the device output on or off in conjunction with input from the CNTL signal. It is also used to set the output voltage to the upper or lower margin voltages. The unit stays in the commanded operating mode until a subsequent OPERATION command or a change in the state of the CNTL pin instructs the device to change to another mode. For PWM loop slave device, which is recognized during power-up calibration, 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 devices provide many sequencing options. Using the ON_OFF_CONFIG command, the device can be configured to start up whenever the input voltage is above the UVLO threshold, to require an additional signal on the CNTL pin, to receive an update to the OPERATION command through the PMBus interface, or a combination of these configurations. When the gating signal as specified by the ON_OFF_CONFIG command is asserted, a programmable turnon delay can be set with the TON_DELAY command to delay the start of regulation. Similarly, a programmable turnoff delay can be set with the TOFF_DELAY command to delay the stop of regulation once the gating signal is deasserted. Delay times are specified in milliseconds (ms), from 0 to 100 ms.Figure 24 shows control of the start-up and shutdown operations of the device when the device is configured to respond to both the CNTL signal and the OPERATION command. The device can also be configured to independently use either the CNTL signal or the OPERATION command, or to convert power when a sufficient input voltage is available.
