| 摘要 |
<p>A driver circuit (10) suitable for use in an operational amplifier, includes a bipolar pull-up transistor (36) which sources current to an output terminal (38) in proportion to an applied drive current, and an MOS pull-down transistor (48) which sinks current from the output terminal (38) in proportion to an applied control voltage. An MOS drive transistor (32) provides a constant drive current for the pull-up transistor (36), and an MOS shunt transistor (44) shunts the drive current away from the bipolar transistor (36) in proportion to the control voltage. A cross-over compensation circuit (14) develops a predetermined bias voltage on the base of the bipolar transistor (36) relative to the voltage on the output terminal (38), to assure a minimum level of operation of the bipolar transistor (36) when the output terminal (38) is near the analog ground voltage.</p> |
