| 摘要 |
<p>In an output amplifier i20) which is operated in class AB with the aid of quiescent-current means 140, 50) and which comprises first output-transistor configuration (T10-T14) and a second output-transistor configuration (T15-T17) with output transistors (T14, T17) of the same conductivity type, the drive signals for these output-transistor configurations are derived from the output signal (Vi) of the input amplifier (10) by means of a single voltage-to-current converter (30). In the case of a positive drive of the first output transistor configuration (T,o-T,4) this converter (30), together with the first output-transistor configuration (T10-T14) and a load (RL) connected to the output (5) of the output amplifier (20), constitutes an amplifier configuration with full negative feedback, whilst in the case of a positive drive of the second output transistor configuration (T15-T17) the converter (30) together with the second output transistor configuration (T15-T17) and the load (RL) also constitutes an amplifier configuration with full negative feedback. As a result of this negative feedback non-linearity of the output transistors is reduced substantially, so that the output voltage (Vo) accurately follows the input voltage (V).</p> |
