发明名称 D/A converter
摘要 A digital-to-analog (D/A) converter includes first resistors coupled in series, second resistors respectively coupled to the first resistors and each having a resistance twice as large as the resistance of the first resistor, and first switch circuits respectively coupled to the second resistors. Third resistors each have a resistance twice as large as the resistance of the first resistor. Second switch circuits each are coupled to the third resistors and a GND wire. A control circuit controls the first and second switch circuit in accordance with the digital input signals to set a state of a connection node to either one of a first voltage, a second voltage, and a high impedance.
申请公布号 US8937568(B2) 申请公布日期 2015.01.20
申请号 US201414163787 申请日期 2014.01.24
申请人 Fujitsu Semiconductor Limited 发明人 Suzuki Hisao
分类号 H03M1/78;H03M1/08 主分类号 H03M1/78
代理机构 Arent Fox LLP 代理人 Arent Fox LLP
主权项 1. A digital-to-analog (D/A) converter that generates an analog signal according to digital input signals, the D/A converter comprising: a plurality of first resistors coupled in series between a first output terminal and a second output terminal from which the analog signal is outputted, the first resistors having a same resistance; a plurality of second resistors including first terminals respectively coupled to the plurality of first resistors and each having a resistance twice as large as the resistance of the first resistor, the first output terminal being coupled to the first terminal of one of the plurality of second resistors; a plurality of first switch circuits respectively coupled to second terminals of the plurality of the second resistors; at least one third resistor having a resistance twice as large as the resistance of the first resistor and including a first terminal coupled to one of the first terminals of the second resistors except for one second resistor that is coupled to the first output terminal; a second switch circuit including a first terminal coupled to a second terminal of the at least one third resistor and a second terminal coupled to a first wire; and a control circuit coupled to the first and second switch circuits and configured to generate a first signal to control the first switch circuits and to generate a second signal to control the second switch circuit, in accordance with the digital input signals, wherein one or more of the plurality of the first switch circuits, which is coupled to the second resistor that is coupled to a node between the first output terminal and a connection node arranged between two adjacent first resistors and to which the first terminal of the third resistor is coupled, is controlled to set a state of a connection node arranged between the one or more first switch circuit and the corresponding second resistor to either one of a first voltage, a second voltage that is different from the first voltage, and a high impedance.
地址 Yokohama JP