| 摘要 |
PURPOSE:To reduce number of components and to decrease power consumption by connecting a base of a transistor (TR) and the 1st and 2nd resistor series bodies to a current source of a reference voltage circuit and connecting the TR in parallel with the 2nd resistor and controlling the TR with an output circuit. CONSTITUTION:TRs Q1, Q2, Q3, Q4, Q5 and resistors R1, R2, R3 constitute a band gap type reference voltage circuit. The relation of VB(ON)<VB(OFF)< VB6(ON)<VB8(ON) is established at a low temperature to turn off Q6, Q8, where VB(ON), VB(OFF) are voltages generated across resistors R2, R3 when the TRQ7 is turned on and off, and VB6(ON), VB8(ON) are voltages when the TRQ6 and the output TRQ8 are turned on. When the relation VB(ON)>VB6(ON) is established at a high temperature, the Q6 is turned on and the Q7 is turned off. Then the base voltage of the TRs Q6, Q8 is VB(OFF), and with the relation of VB(OFF)>VB(ON), the Q8 is turned on to attain thermal protection. |
