| 摘要 |
PROBLEM TO BE SOLVED: To provide a ladder resistor type D/A conversion circuit whereby the cost can be reduced by decreasing the number of buffers in use while decreasing the number of resistors in use and a D/A conversion output with high accuracy can be obtained. SOLUTION: A control circuit 23 applies switch control to analog switches 16, 18, 19, 21, 22 to form series connection of first and second ladder resistors 2, 3 thereby causing a state that a voltage V2 is applied between both end terminals of the ladder resistors 2, 3 in the series connection, and provides an output of a D/A conversion signal from an output terminal OUT 2 through a first buffer 14 or a second buffer 15 on the basis of a 4-bit digital signal. Further, the control circuit 23 applies switching control to the analog switches 16, 18, 19 so as to separate the first and second ladder resistors 2, 3 from each other and provides an output of 3-bit D/A conversion signals from output terminals OUT 1, OUT 2 through the first and second buffers 14, 15. COPYRIGHT: (C)2005,JPO&NCIPI
|
