| 摘要 |
PURPOSE:To simplify a circuit by providing a chopper type comparator consisting of a body obtained by serially connecting a switch, a capacitor and an inverter in which a switch is connected in parallel, where the opening/closing timing of the respective switches is controlled by a CPU. CONSTITUTION:An analog circuit for controlling various power sources for forming an image including a switching regulator, the CPU for controlling sequence, a digital circuit such as a memory and a counter on the periphery thereof are integrated on the same chip. The analog circuit for controlling various power sources is constituted by including the chopper type comparator Cs3 consisting of the body obtained by serially connecting the switch S3, the capacitor C403 and the inverter in which the switch S4 is connected in parallel, where the opening/closing timing of the respective switches S3 and S4 is controlled by the CPU Q1 on at least a part of the analog circuit. As to the analog circuit for controlling the power source, the large scale capacitor for inputting/ outputting need not be externally mounted and a chip occupied area can be made smaller. |
