| 摘要 |
PURPOSE:To simplify the constitution of an I<2>L circuit, by comparing a signal corresponding to a constant current in response to an injection current of the I<2>L circuit with a reference signal, and controlling the injection current with the compared result to prevent the fluctuation in the output current. CONSTITUTION:A constant voltage power supply 1 consists of bipolar transistors (Trs) Q1-Q3 Zener diode D1, diodes D2, D3 and resistors R1-R3. A voltage drop across the resistor R3 of the power supply 1 is inputted to a voltage comparator circuit 2 as a reference voltage. Further, a current source 3 generates the injection current Iinj applied to Trs Q11-Q14 constituting the I<2>L circuit and a signal corresponding to the constant current IX of the TR14 in response to the current Iinj is applied to the circuit 2. The reference voltage from the power supply 1 and the signal corresponding to the constant current IX in response to the current Iinj are compared at the circuit 2, the current source 3 is controlled with the result of comparison to prevent the fluctuation in the output current, allowing to simplify the constitution of the I<2>L circuit. |
