Big Caps after VoltageRegulator?


2001-10-23 8:44 pm
i want to upgrade the digital PSU of my CDP with a big (10000uF) Cap which i have lying around. Is it a problem to have such a large cap installed after the voltage regulator regarding to oscillation or inrush current? The regulator is a LM340T5 rated 1.5A. I can´t use the cap in front of the regulator because of its voltage rating.

Inrush current is not a problem as the LM340T5 is overcurrent protected.

But mount a schottky diode or a fast recovery diode (2 amp. type) with catode connected to Vin and Anode connected to Vout to protect the LM340T5 against reverse biasing, which it cannot handle very well.

Oscillation can be prevented with two fast 100nF caps from Vin and Vout to the ground pin.