Granted Patent B2

US 8,397,571 · App. 12/781,796 · Granted Mar 19, 2013

Abstract

Claims (13)

1. An output circuit, comprising:

a first capacitor sequentially provided with sensor measurement signals from a plurality of sensors;

a differential amplification circuit arranged for each sensor and including a first terminal, which receives a voltage of the first capacitor, and a second terminal, which receives a reference voltage for correcting the sensor measurement signals;

a hold capacitor arranged in each differential amplification circuit between an output terminal and the first terminal;

a correction coefficient generation circuit that sequentially provides correction coefficients for correcting the sensor measurement signals of the sensors;

a second capacitor that accumulates the correction coefficients from the correction coefficient generation circuit and provides the correction coefficients to the second terminal of the differential amplification circuit; and

a first switch circuit that connects the second capacitor to each differential amplification circuit in synchronism with the sensor measurement signals.

2. The output circuit of claim 1 , wherein the first switch circuit executes a reset phase to short circuit two ends of the second capacitor before connecting the second capacitor to each differential amplification circuit.

3. The output circuit of claim 2 , further comprising:

a second switch circuit arranged in each differential amplification circuit to connect a third capacitor between the output terminal and the first terminal;

wherein the second switch circuit connects the third capacitor to each differential amplification circuit in synchronism with the sensor measurement signals.

4. The output circuit of claim 3 , wherein the second switch circuit short circuits two ends of the third capacitor in the reset phase.

5. The output circuit of claim 1 , wherein the first capacitor is connected to an acceleration sensor that measures acceleration for a plurality of axes, and obtains from the acceleration sensor a signal that arranges acceleration detection signals for each axis in chronological order as the sensor measurement signals.

Assignments (29)