| 摘要 |
A D/A converter is comprised of a string of resistors coupled to a voltage source with respective junctions formed between adjacent resistors, including a reference junction substantially at the mid-point of the resistor string. Plural switches are coupled to the junctions and are selectively operable to couple a potential produced at a respective junction. A subtracting circuit has one input coupled in common to a first set of the switches and another input coupled in common to a second set of the switches to subtract the potential coupled from one set from the potential coupled from the other set so as to produce an output analog signal. A switch control circuit is responsive to a multi-bit digital signal for operating predetermined switches in both the first and second sets and thereby couple to the subtracting circuit the potentials which are produced at corresponding junctions on either side of the reference junction. |
