| 摘要 |
PURPOSE:To form a reference amount for A/D conversion with high accuracy by providing two capacitors, a control circuit controlling charge/discharge of the capacitors and two sample and hold circuits and adding outputs of both the sample and hold circuits to obtain the reference amount for conversion. CONSTITUTION:Switches 2, 5 are used for discharge of the capacitor C1 and switches 5, 6 are used for discharging the capacitor C2 respectively. Then the output of the capacitor C2 is an input to the sample and hold circuit 3 and an output of the capacitor C1 is an input to a sample and hold circuit. 7. The outputs of both the sample and hold circuits are added by an adder circuit 8 and the result is used as a reference output. The on/off control of the switches 1, 2 , 5 and 6 is performed by control signals A, B, C and D generated from a control circuit 9 respectively, and the circuits 3, 7 performs sampling by a sampling pulse generated from the control circuit 9. |
