12-to-24 V Converter

This DC-to-DC converter delivers a maximum power of about 36 watts at an efficiency of 90%. Apart from a modern FET and a Schottky diode, this circuit is comprised entirely of familiar and inexpensive parts. In spite of this, the specifications are excellent:– Efficiency: approx 90%– Ripple voltage: max. 10 mV– Output current: max. 1.5 A– Switching frequency: 40 kHz– Input voltage: 12 V– Output voltage: 24 V regulatedThe switching element is a fast power FET (T8). This FET has a relatively high input capacitance and is switched on and off by a push/pull stage consisting of two RF transistors (T5/T6). Schottky-diode D2 increases turn-off speed even further, which is crucial here because we are aiming to obtain the highest possible efficiency.