The TPS72301DBVR is a -200mA low-dropout negative voltage regulator in SOT-23-5. It uses a PNP pass transistor that allows very low dropout voltage of 170mV at 200mA. The output voltage is set by an external resistor divider between OUT, FB, and GND, with the FB pin regulated to -1.186V. The feedback loop operates by comparing the divided output voltage against the internal reference: the error amplifier adjusts the PNP pass transistor base drive to maintain the FB pin at -1.186V. Since the device regulates a negative voltage, the GND pin is the most positive terminal, and current flows from GND through the load to the negative OUT pin. The EN pin enables/disables the output; when disabled, supply current drops to 2uA. The device features current limiting and thermal shutdown protection.