Patent attributes
A digital-analog converter includes a counter (13) for performing counting operation according to clocks (CK1, CK2), a comparator (12) for comparing the count value to a digital input value and outputting the clocks (CK1, CK2) until the values coincide, switches (SW1, SW2) which turn ON/OFF according to the clocks (CK1, CK2), and a capacitor (C1) which charges and discharges by utilizing constant current sources (21, 22) when the switches (SW1, SW2) are ON. A digital portion (10) including the comparator (12) and the counter (13) is completely separated from an analog portion (20) including the capacitor (C1) and the switches (SW1, SW2) and these portions are connected only by the clocks (CK1, CK2), so that the digital portion (10) and the analog portion (20) can be designed separately.
