| 摘要 |
An auto reset circuit of an MICOM is provided to reset the MICOM automatically when the source voltage of an MICOM IC becomes 0v or is larger than the current set in a current sensing resistor. If an MICOM IC is in a latch-up state by external or various surge voltages, the current flows into a PNP type transistor(Q11) and NPN type transistor(Q12) even without the external signal. The base voltage of a transistor(Q10) becomes 0v when the NPN type transistor is the ON state so that an MICOM can operate in the steady state after being reset. Therefore, the source voltage(+5V) is prevented from being 5v. When the normal operation is started, a DC-rectified voltage is charged in a condenser(C7) by a diode(D6) through a condenser(C5) for cutting the DC and then is triggered to the base of the NPN type transistor(Q13) through base resistors(R16, R17).
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