TLF35584 data sheet indicates "In case of over voltage at pin QTx, the corresponding tracker will be switched off, the event will be stored in an SPI status register (MONSF1) and an interrupt will be generated."
When the over voltage event ends, how/when does the tracker turns back on ?
- does tracker self recovers and turns on or
- does clearing the status register MONSF1 recovers the tracker ?
The TLF35584 includes an independent voltage monitoring function of all output voltages, including the optional external post regulator for µC core supply, if in use. The monitoring function consists of two comparators for each output voltage. One is for detecting over voltage, the other is for detecting under voltage. Both comparators get their reference value from an independent bandgap only used for the voltage monitoring block. This bandgap is independent from the voltage regulator bandgap. The bandgap provides the reference value for over voltage detection (highvoltage reset threshold VRT,xxx,high) and for under voltage detection (low voltage reset threshold VRT,xxx,low). Under normal operation conditions the output voltage of the related regulator has to stay within the voltage window defined by the upper limit VRT,xxx,high and the lower limit VRT,xxx,low.
The linear trackers 1 and 2 offer a sensor supply with a very high accuracy referred to voltage reference output
(pin QVR). Both trackers are supplied by the intermediate circuit voltage VPREREG, which provides a stabilized voltage. The output voltage VQTx at pin QTx is controlled by the error amplifier. The actual value is compared to a reference voltage provided by the reference voltage VQVR at pin QVR.
An over voltage will be detected if the regulator output voltage is higher than the related over voltage reset
threshold VRT,xxx,high for more than the reset reaction time tRR. An over voltage higher than the related over
voltage reset threshold VRT,xxx,high which is present for shorter than the reset reaction time tRR will be regarded as a spike and will not be detected.
The output voltage is monitored by the voltage monitoring. In case of over voltage at pin QTx, the
corresponding tracker will be switched off, the event will be stored in an SPI status register (MONSF1) and an
interrupt will be generated.
Reaction of detected faults:
The OV failure will not trigger a movement of the device to another state by it alone, but will indicate the
failure by an interrupt event:
Both the trackers are controlled independently by SPI as shown below,
Hence it goes into reset mode with reset delay time and later controlled by SPI based on the voltages sensed on QT1 and QT2 pins. This completely depends on the microcontroller. After the related output are shut down, TLF35584 will not reopen it autonomously when the voltage is recovered. TLF35584 will generate a interrupt signal to MCU. It is the system's decision that whether to reopen it. The decision is based on the over heating ( temperature rise due to OV) and a delay is usually seen when reset takes place.