| 摘要 |
<p>PURPOSE:To protect a transistor (TR) at output stage, by providing a circuit in which the output state is made to a high impedance in accordance with the increase in power supply. CONSTITUTION:In a power supply voltage variance detection circuit VD, when a power supply voltage Vcc increases, a Zener diode D3 turns on, resulting that a TRQ5 turns on, the collector of a Q2 is grounded, and Q3, Q4 at the output stage are turned off.</p> |
