LM27761: Support 3Vin, output -4.2V

Hi Will,

The abs value of the LM27761 output will be less than the VIN. You also have to consider the voltage drop across the charge pump output impedance and LDO drop out voltage. For 3V VIN and 50mA current, the drop across the charge pump output impedance is around 150mV and LDO dropout voltage is 18mV. So the output will be around -2.83V.

Best regards,

Varun