| 摘要 |
<p>A class AB amplifier having an output stage comprising complementary common source transistors (T1, T2) has means for setting the quiescent current. These comprise a bias resistor (R1) through which a bias current is passed and which is connected between the gates of transistors (T1 and T2) to set their voltages. The current through the bias resistor (R1) is derived from two reference transistors (T3 and T4) which each have the desired quiescent current passed through them by current sources (3, 5). The gate voltages of the reference transistors (T3, T4) are applied across a reference resistor (R2) and the current through the reference resistor (R2) is mirrored (T5 to T9) to the bias resistor (R1).</p> |
