Output buffer circuit capable of enhancing stability

摘要

An output buffer circuit capable of enhancing stability includes an operational amplifier, a capacitive load and an output control unit. The operational amplifier has a positive input terminal, a negative input terminal and an output terminal, and generates an output voltage to the output terminal according to an input voltage received by the positive input terminal. The output control unit is coupled between the output terminal of the operational amplifier and the capacitive load, and is utilized for controlling electrical connection between the output terminal of the operational amplifier and the capacitive load to form a signal output path and for adjusting impedance of the signal output path when the signal output path is formed. The output control unit comprises a plurality of output switches for individually turning on or off the electrical connection between the output terminal and the capacitive load of the operational amplifier.

主权项

1. An output buffer circuit capable of enhancing stability, comprising:
an operational amplifier, having an output terminal; and an output control unit, coupled between the output terminal of the operational amplifier and capacitive load, to generate a variable impedance of a signal output path between the output terminal of the operational amplifier and the capacitive load, wherein when the operational amplifier enters an output phase to charge or discharge the capacitive load, the output control circuit generates a first impedance, and when a voltage level of the capacitive load is detected to reach a predetermined level, the output control circuit generates a second impedance larger than the first impedance.