| 摘要 |
PURPOSE:To attain a comparatively fast output of intermediate voltage to an output terminal when an error occurs, by using a complementary push-pull output MOSFET containing a capacitor set at its gate as a circuit which produces the output voltage of an intermediate level. CONSTITUTION:When an error signal ERR is produced, the potential of a common source between the MOSFETs Q9 and Q10 is reduced relatively with respect to the gate voltage (Vcc/2+Vthn1) of the FETQ9 since the potential of an output terminal Dout is kept at a low level. When this difference voltage is set higher than Vthn2, the FETQ9 is turned on to increase the output voltage up to (Vcc/2+Vthn1-Vthn2). Here it can be avoided that the potential of the gate of the FETQ9 is at a low level owing to a fact that a capacitor C3 is provided to said gate. Therefore, the FETQ9 rises the terminal Dout up to an intermediate voltage level from a low level at a high speed with comparatively large conductance.
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