| 摘要 |
PURPOSE: A start up circuit is provided to operate by small power consumption and a plurality of node voltages has a normal voltage level within a short time. CONSTITUTION: A start up circuit(200) comprises a differential amplification block, a first MOS transistor(M1), a third MOS transistor(M3), a first bipolar transistor(Q1), an eleventh resistance(R11), and a reference voltage output block. The differential amplification block outputs a first response voltage(Vo1) and a second response voltage(Vo2) in response to the first input voltage(Va) and the second input voltage(Vb). A terminal of the first MOS transistor is connected to the first supply voltage. The first response voltage is applied to the gate of the first MOS transistor. A terminal of the third MOS transistor is connected to one terminal of the first MOS transistor. The second response voltage is applied in the gate of the third MOS transistor. A terminal of the first bipolar transistor outputs the first input voltage. Another terminal and the base are grounded in the first bipolar transistor. The eleventh resistance is arranged between the first input voltage and the ground voltage. The reference voltage output block produces the reference voltage(Vref) in response to the first response voltage and the second response voltage. |
