| 摘要 |
PURPOSE:To offer an amplifier from which a large current output is obtained and having a large dynamic range by controlling a current of a current source of the 2nd differential amplifier circuit in response to a differential output of the 1st differential amplifier circuit. CONSTITUTION:A resistance series circuit comprising resistors R5, R6 (R5=R6) is inserted between drains of field effect transistors (TR)Q1, Q2, a connecting midpoint is connected to a base of an NPN TRQ5, the emitter is connected to a current source I3 via a temperature compensation diode D1 and a resistor R7 and a circuit power supply is impressed to the collector. When the input between terminals (a), (b) is large and an output exceeds an i20, a further larger input is impressed to the base of TRs Q3, Q4 and one TR is cut off. Moreover, the maximum capable current output i2max is in the relation of i2max R3.I1/2Rs with R5>>R3 and R6>>R4 and then the i2max is a very large value.
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