| 摘要 |
<p>The control voltage phi 1 outputted by the control voltage generating circuit (1) is at a low level in a range where an external supply voltage Vcc is lower than the threshold value of the transistor (P1), but increases continuously in analog manner when the external supply voltage Vcc rises. After having matched the external supply voltage Vcc, the control voltage phi 1 increases in the same way as the external supply voltage Vcc. By use of the control voltage provided with the characteristics as described above for an output circuit, controlled is the gate of a transistor (P4) of a low-voltage operating output section (6) operative only at a voltage lower than a predetermined value. The transistor (P2) of a full-voltage operating output section (5) of the output circuit is always operative on the basis of the control signal phi H of the data output control circuit (3). When the external supply voltage is low below the predetermined value, the transistor (P4) is perfectly turned on, so that the conductance thereof increases. In the semiconductor integrated circuit device operative on the basis of a plurality of supply voltages, it is possible to prevent the operation margin from being reduced near the switching point of the gate voltages of the driving transistors and the data output transistors. <IMAGE></p> |
