| 摘要 |
A resistor string digital-analog conversion circuit includes three resistor strings (RS1,RS2,RS3) connected in series, a controller (21), and a switch group (SW). The controller (21) controls switchover of the switch group (SW) according to a signal of m high-order bits of an input digital signal. Thus an analog output corresponding to the m high-order bits is obtained. Another controller (2) varies potentials of two variable voltage sources (VH,VL) according to a signal of n low-order bits of the input digital signal, while always keeping a potential difference across the three resistor strings (RS1,RS2,RS3) constant. Thus an analog output corresponding to the n low-order bits is obtained. This analog output is outputted to an output terminal (26). <IMAGE> |
