Patent ID: 7365666

Claim:
A voltage conversion device having non-linear gain and changeable gain polarity, for converting analog voltage provided by an analog voltage source, the voltage conversion device comprising: a switch module coupled to the analog voltage source and a system ground end, for outputting analog voltage provided by the analog voltage source or voltage corresponding to the system ground end according to a polarity selection signal; a gain decision module comprising: an analog-to-digital (A/D) converter coupled to the analog voltage source, for converting analog voltage provided by the analog voltage source into digital signals; and a gain selector coupled to the A/D converter and the switch module, for determining a gain according to the digital signals outputted from the A/D converter; a first voltage selection module coupled to the A/D converter, for outputting a first direct-current (DC) voltage selected from a plurality of DC voltages according to the digital signals outputted from the A/D converter; a second voltage selection module coupled to the analog voltage source and the A/D converter, for outputting a second DC voltage according to analog voltage provided by the analog voltage source, one of a plurality of DC voltages and the digital signals outputted from the A/D converter; a first switch unit coupled to the first voltage selection module, for outputting the first DC voltage according to the polarity selection signal; a second switch unit coupled to the second voltage selection module, for outputting the second DC voltage according to an inverse signal corresponding to the polarity selection signal; and a voltage output module comprising a first input end, an output end coupled to the gain selector, and a second input end coupled to the first switch unit and the second switch unit, for outputting an amplified result of the DC voltage received by the second input end according to the gain determined by the gain selector.