| 摘要 |
PURPOSE:To improve the precision of a D/A converting circuit which uses IGFETs by turning on the 1st IGFET by the 1st clock and charging a capacitive element, and turning on the 2nd IGFET by the 2nd clock and discharging the capacitive element repeatedly. CONSTITUTION:In response to the 1st clock phi1, IGFETs Q4 and Q2 are turned on to move charge from a power source 23 to the capacitive element C3 and in response to the 2nd clock phi2, an IGFETQ3 is turned on to move charge from the element C3 to capacitive element C2. Then, a digital input signal synchronizing with the clocks phi1 and phi2 repeated without overlapping each other is supplied from a terminal 24 to an IGFETQ5 to move charge from the element C2 to a holding capacitive element CS, obtaining an analog signal corresponding to the digital input signal from the charging potential of the element CS. |
