| 摘要 |
1,158,416. Transistor amplifier circuits. INTERNATIONAL BUSINESS MACHINES CORP. 15 Nov., 1966 [13 Dec., 1965], No. 51033/66. Heading H3T. In an amplifier comprising at least one amplifier transistor 2-1-2-n, the input circuit of the amplifier includes at least one input transistor 6-1 having the same base-emitter characteristics as the amplifier transistor and having its base and collector electrodes connected together to an input terminal 7 and to the base electrode of the amplifier transistor and the or each input transistor 6-1-6-n is biased so that the collector current I1-I5 of the or each input transistor substantially equals the collector current I o which flows through the or each amplifier transistor. This bias is provided by supply 9 and a resistor 10. The gain and input impedance of the amplifier may be reduced by increasing the number of input transistors used: or the gain and input impedance may be increased by reducing the number of input transistors and adding further amplifier transistors 2-n in parallel with each other. The amplifier may be constructed as an integrated circuit. The output from the amplifier 1 may be connected to a direct current amplifier (20, Fig. 2, not shown), the output of which is fed back to bias the amplifier at point 11 via a negative feedback network (22). |
