| 摘要 |
PURPOSE:To control a minute current with high accuracy by using diodes connected in opposite polarity as a constant current source of a D/A converter. CONSTITUTION:The D/A converter consists of ladder resistors R, 2R, current switches SW1-SW4, and the diodes 1-4. When the switches SW1, SW2 and SW4 are closed, reverse currents ID1, ID2 and ID4 flow respectively to the diodes 1, 2 and 4, they are respectively an identical current value and a current Iout subjected to A/D conversion flows to a resistor RX. In constituting the constant current source comprising the diodes and the current switches or the like on one chip, a one-chip D/A converter is realized. |
