| 摘要 |
A supply voltage switch circuit for use with programable arrays such as EPROMS includes a pair of P-channel transistor switches connected in series between a high programing supply voltage and a low read supply voltage wherein the circuit junction between the transistors is connected to a row/column-select supply line. A switch control circuit is connected to the switches to alternately connect the row/column-select supply line to one or the other of the supply voltages in response to a logic signal. A third P-channel transistor may be connected in the series circuit, under control of the logic signal, to prevent destructive transient currents from flowing when powering up the high supply voltage source, at which occasions both of the two principal switches tend to momentarily turn on.
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