Patent ID: 8242992
Filing Date: 2012-08-14
Classification: H03F

Abstract:
1. A driving apparatus, comprising: a digital to analog converter, receiving a digital data and converting the digital data into an analog signal; and a signal amplifier, coupled to the digital to analog circuit, receiving the analog signal and generating a driving signal and dynamically changing a driving capability of the driving signal according to at least one bit of the digital data, wherein the signal amplifier comprises an operational amplifier, the operational amplifier comprises: an input stage, coupled to a positive input terminal and a negative input terminal of the operational amplifier, receiving the analog signal; and a gain stage, coupled to the input stage, generating the driving signal according to an output from the input stage, wherein the gain stage comprises a controlled capacitance, the controlled capacitance comprises a plurality of capacitors coupled in parallel between a first terminal and a second terminal of the controlled capacitance, and a capacitance of the controlled capacitance is determined according to the at least one bit of the digital data a control terminal of the operational amplifier so as to determine the driving capability of the driving signal.