| 摘要 |
<p>PURPOSE: A reference voltage generating circuit is provided to prevent the operation point of a bias voltage generating part from being a zero state by adopting a start-up circuit which has a voltage dividing part. CONSTITUTION: A reference voltage generating part(60) generates a uniform reference voltage in response to a bias voltage. A bias voltage generating part(40) generates a bias voltage. A start-up circuit operates the bias voltage generating part after receiving a first supply voltage. A first MOS transistor includes a gate which is connected to the output of a differential amplifier, a source and a drain which are connected to a second supply voltage and a first node voltage, respectively. A second MOS transistor includes a gate which is connected to the output of a differential amplifier, a source and a drain which are connected to a second supply voltage and a second node voltage, respectively. A third MOS transistor includes a gate which is connected to the output of a differential amplifier, a source and a drain which are connected to a second supply voltage and a reference voltage, respectively. A first bipolar transistor includes an emitter which is connected between a first node voltage and a reference electric potential and a base which is connected to a reference electric potential, and a collector. A start-up circuit(10) offsets the change of the first supply voltage to maintain the separation from the bias voltage generating part.</p> |
