| 摘要 |
<p>PURPOSE:To eliminate the dependance on the power supply voltage and the temperature for a constant potential difference generating circuit, by flowing the equal currents to the 1st and 2nd transistors and inserting a resistance and the 3rd transistor to each of the 1st and 2nd transistors, respectively, to produce a fixed potential difference. CONSTITUTION:A constant potential difference circuit consists of a band gap voltage source 1 connected between a power supply line 2 and an earth terminal and the 1st and 2nd npn transistors Tr Q1 and Q2 whose bases receive supply of said band gap voltage. Then the 3rd Tr Q3 connected with a resistance R2 via a diode is connected in series between the line 2 an the collector of the Tr Q1. In addition, a resistance R3 is connected between the collector of the Tr Q2 and the line 2. Thus voltages VH and VF are produced between output nodes 3 and 4 and the line 2 respectively by the currents I of both Tr Q1 and W2. Then the difference between both voltages is set so as to satisfy R1=R2-R3. Thus it is possible to obtain the difference voltage of a fixed level that is free from dependance on the power supply voltage and the temperature.</p> |
