| 摘要 |
PURPOSE:To attain high accuracy and low power consumption, multifunction and small size and light weight, by forming the circuit from an analog input to a display driving circuit including a switch group on one silicon chip. CONSTITUTION:As LSI block 17 of a multifunctional analog-to-digital conversion instrument is added with a boosting circuit 15 and an interface circuit 16 for an analog switch controlling signal. A signal from an analog input terminal 1 of the block 17 is applied to switch groups 2-1-2-3 for function switching, and the output is applied to an input changeover switch group 5 via a rectifier circuit 4. The output of the switch group 5 is digitally converted at an A/D conversion circuit consisting of a reference voltage source 6, an integration circuit 7 and a comparison circuit 8 and displayed on a display 12 via a control logical circuit 10. The voltage from the circuit 10 is interfaced at a circuit 16 to switch the switch groups 2-1-2-3,5, allowing to reduce the area of the block 17 in comparison with direct control, and the power supply voltage is operated as <=+ or -3V. |
