| 摘要 |
PROBLEM TO BE SOLVED: To provide a converter interface with high performance, small area and small power. SOLUTION: An input of a sigma-delta converter is connected to a combination where a 1st switched capacitor modules SC1, SC1b, a 1st differential amplifier A1, a 2nd SC2, and a 2nd differential amplifier A2 are connected in series and a comparator CP is connected to the post-stage. The modulator also includes a 3rd SC3 and a 4th SC4 that receive a reference voltage and are connected to inputs of the 1st and 2nd differential amplifiers. An offset correction preamplifier leading to an analog-digital converter is replaced with a 5th SC5, to which an offset voltage is applied and supplied from a resistor array SRSa selected by a reference voltage. The converter is provided with a gain setting means simplified for the interface in addition to improved offset correction. The gain setting device consisting of branches of one or more switching capacitors is coupled in parallel with a capacitor already inexistence in the 1st SC1b.
|
