| 摘要 |
PROBLEM TO BE SOLVED: To allow for supplying the analog signal of a circuit on the primary to a circuit on the secondary, while converting into a digital signal, and insulating the circuit on the primary and the circuit on the secondary, without using an isolator such as a photocoupler.SOLUTION: An analog/digital conversion circuit (11) has capacitive elements (12, CIN1, CIN2), an input switch circuit (111) for storing charges, corresponding to an analog signal supplied, in the capacitive elements at each prescribed period, and a digital signal generation circuit (112) generating a digital signal by performing &Dgr;&Sgr; modulation of a signal based on the charges stored in the capacitive elements at each prescribed period. The input switch circuit and digital signal generation circuit operate with power supplies (VCC-GND1/VDD-GND2) different from each other, and are insulated from each other by the capacitive elements.SELECTED DRAWING: Figure 1 |
