| 摘要 |
<p>A voltage supply circuit starts up a system while maintaining the symmetry of high-level and low-level selection voltages (VH, VL). The voltage supply circuit needs no multistage charge pump circuit, thus requiring a smaller number of components. A circuit for producing VD and VH is composed of a step-up switching regulator using a chopper. A VH generator (12) and a VL generator (13) are controlled in timing of their switching so that a virtual reference voltage VS (VD/2) may coincide with the intermediate potential between VH and VL.</p> |
