| 摘要 |
<p>The amplifier includes two complementary transistor differential input stages (Q1,Q2,Q4,Q5). A first current source (10) is switched as a function of the input voltage to activate one or other of the input stages by establishing a quiescent current (TI1). A folded cascode stage has two transistors (Q8,Q9) which have currents (I2) determined by the bias voltage (Vb) and reduced by circulating currents (I1) in one (Q1,Q2) of the input stages. Current-mirror input and output transistors (Q12,Q13) are switched at the same time as the current source, to hold the cascode current constant when a differential stage changes between active and inactive modes.</p> |
