Question
1. Which voltage is necessary at the REGEN pin (min/max) to activate the
internal voltage regulator?
2. Is it possible to apply an external logic (signal) to REGEN pin while PVDD
is switched off?
3. Is the internal regulator (VREG) switched off in case of an temperature
exceeding ~145°C?
4. If the temperature rises above 120°C the THERM pin is logic high according
to the "Applications Information - Amplifier Protection" and open collector
output according to the "Pin Function Descriptions". Which information is
correct?
5. Is the pull-up resistor allowed to pull the THERM pin to PVDD?
Answer
1. The active high for REGEN pin is 1.35V to 5.5V, so it should be able to
handle the normal CMOS logic voltage levels.
2. the internal 5V then PVDD must be present before you could turn on/off the
part as the internal logic will need the power to operate from.
3. If the thermal flag is set the part shuts down the output power stage not
the AVDD regulator.
4. The THERM pin is active low i.e. open drain output and would need external
pull up. As per Eval Board schematic, it could sink typical 1-2 mA current. You
would need to size the resistor according to the supply voltage you are pulling
it to.
5. It is not recommended to pull the THERM pin to PVDD, as it may not be able
to withstand the high voltage.