malli_1729
Full Member level 5
Hi,
We are using MCP1825 to power a board which has mainly a Xmega MC,Current sensing, Voltage sensing and Some extra circuitry.
as this LDO has PMOS as pass element which has parasitic or body diode connected between Vout to Vin, we are planning to remove reverse current flowing case.
when we have searched the web we have found these explanations.
1. Having diode in betweeb the Vout of regulator and Vout capacitor, which will stop the Reverse current flowing when Vout>Vin case occurs. This case has limtations like The Vout should have variation of Vf of schottky diode and diode should withstand full load current of 500mA. most of the diodes forward voltage is varying from 0.4 to 0.6 around 0.3V variation in their Vf from min current of let's say 50mA to 500mA. this much variation in Vout i don't want.
2. Having diode paralel to body diode connected in same polarity.so,that before body diode gets forward biassed and allows more current, the paralel diode should be forward biassed and allow current to Vin. We don't want Current to fed to input.
any suggestions will help me.
We are using MCP1825 to power a board which has mainly a Xmega MC,Current sensing, Voltage sensing and Some extra circuitry.
as this LDO has PMOS as pass element which has parasitic or body diode connected between Vout to Vin, we are planning to remove reverse current flowing case.
when we have searched the web we have found these explanations.
1. Having diode in betweeb the Vout of regulator and Vout capacitor, which will stop the Reverse current flowing when Vout>Vin case occurs. This case has limtations like The Vout should have variation of Vf of schottky diode and diode should withstand full load current of 500mA. most of the diodes forward voltage is varying from 0.4 to 0.6 around 0.3V variation in their Vf from min current of let's say 50mA to 500mA. this much variation in Vout i don't want.
2. Having diode paralel to body diode connected in same polarity.so,that before body diode gets forward biassed and allows more current, the paralel diode should be forward biassed and allow current to Vin. We don't want Current to fed to input.
any suggestions will help me.