| 摘要 |
PROBLEM TO BE SOLVED: To provide a low distortion differential amplifier circuit which obtains high voltage gain even in a low voltage operation when the circuit is adapted to a mixer circuit or a variable gain amplifier circuit. SOLUTION: The low distortion differential amplifier circuit is provided with arithmetic amplifiers 3 and 4 whose respective negative inputs are connected to input terminal 1 and 2, transistors 21 and 22 whose respective bases are connected to the respective outputs of the amplifiers 3 and 4, constant current sources 41 and 42 which are respectively connected to parts between the respective emitters of the transistors 21 and 22 and a grounding terminal 8, constant current sources 43 and 44 which are respectively connected to parts between the respective collectors of the transistors 21 and 22 and a power source terminal 7, a resistor 31 connected to a part between the collectors of the transistors 21 and 22, transistors 23 and 24 whose emitters are respectively connected to the respective emitters of the transistors 21 and 22 and also whose bases are mutually and commonly connected and load resistors 32 and 33 which are respectively connected to parts between the respective collectors of the transistors 23 and 24 and the power source terminal 7.
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