The text says: "When Vin is high the diode is FB and capacitor charges up to peak. When Vin is low the diode is RB and the capacitor tends to discharge. The reason given for this is the diode leakage currents.."
But i don't understand one thing that is that as we know that the leakage current of diode is the current that the diode will leak when a reverse voltage is applied to it and the leakage current is entire function of the reverse bias voltage applied to it...so why the text tells us that this leakage current of diode is responsible for the discharge of the capacitor...??