| 摘要 |
PURPOSE:To establish the voltage comparison circuit of high accuracy, by providing the comparison circuit between the reference potential and input voltage and the differential amplifying circuit to one of the inputs of which the reference voltage is applied and in which the output is negative-fed back to another input. CONSTITUTION:The differential amplifying circuit taking the input of the output of the level shift circuits Q4 to Q6 and Q7 to Q9 to which the reference voltage Vref is applied to the input, consists of the differential pair transistors TrQ24 and Q25, emitter constant current TrQ26 resistor R16, and output TrQ27, Q28, and negative feedback is made to the base of TrQ25 via the registor R18. This differential circuit constitutes the voltage follower circuit of the level shift circuits Q7 to Q9 giving the comparison reference voltage. TrQ30 to Q34 constitute the voltage comparison circuit of the output voltage of the level shift circuits Q1 to Q3 taking the input voltage Vi as the input and of the reference voltage with the resistor R21, and the threshold voltage of the voltage comparison is independent of the dispersion if the gain of Tr through the same form of the negative feedback differential circuits Q24 to Q28, allowing to establish the voltage comparison circuit of high accuracy. |
