- on Power Supplies
- Published in issue 7/2003 on page 0
Step-Down Switching Regulator
for Negative Voltages
Special switching regulator ICs for negative voltages are conspicuously absent in the catalogues of semiconductor manufacturers. However, you can make do with a positive-voltage regulator IC and a few circuit tricks.Switching regulator ICs are used for voltage conversion with minimal losses. If you want build a high-efficiency circuit to convert a positive voltage to a higher or lower voltage, you can choose from a large number of switching regulator ICs from several manufacturers. However, if you want to convert a negative voltage, the situation is rather different. There are practically no special ICs available for this purpose, and typical application circuits showing how this problem can be solved are equally scarce. This article shows how a step-down regulator for negative voltages can be built using readily available positive-voltage switching regulator ICs.