| 摘要 |
An amplifier circuit (14') for canceling variations in an amplifier feedback signal includes compensation circuitry (50) defining a replica of the feedback current therethrough. The replicated feedback current is drawn from a circuit node (N1) which directs the feedback signal to a differential pair (Q1, Q2) of the amplifier circuit 14', whereby any biasing effects on the differential pair (Q1, Q2) due to changes in the feedback signal resulting from changes in a gate drive output voltage (VGD) of the amplifier circuit (14') are eliminated. Accordingly, the gate drive output voltage (VGD) may be used to control an ignition coil (L1) drive transistor (16) whereby any changes in gate drive voltage (VGD) will not cause the coil current (IL) to deviate from its target coil current limit value.
|
