发明名称 |
CIRCUIT AND METHOD FOR REDUCING NON-LINEARITY ANALOG OUTPUT CURRENT DUE TO WASTE CURRENT SWITCHING |
摘要 |
An integrated circuit digital to analog converter includes circuitry having first and second resistors in a R/2R resistor ladder which scales bit current contributions to an analog output current. Each of the first and second resistors have a respective terminal connected to the collector of a bit current transistor, the emitter of which is connected to the emitter of a waste current transistor. The digital to analog converter includes a metal ground voltage conductor having a "shared node" and a distributed resistance between one side of the shared node and a main ground voltage connection. The collector of the waste current transistor and a second terminal of the first resistor are both connected directly to the shared node. In operation, the waste current transistor switches waste current into the shared node, rather than into a separate waste current ground conductor. This results in substantially less voltage variation across the distributed resistance of the metal ground voltage conductor, and consequently lower non-linearity, than is the case if waste current is switched into the separate ground conductor. |
申请公布号 |
GB2139441(B) |
申请公布日期 |
1986.11.05 |
申请号 |
GB19840002251 |
申请日期 |
1984.01.27 |
申请人 |
* BURR-BROWN RESEARCH CORPORATION |
发明人 |
ANTHONY D * WANG;DONALD L * BRUMBAUGH |
分类号 |
H03M1/78;H03M1/00;H03M1/06;H03M1/68;H03M1/74;(IPC1-7):H03K13/02 |
主分类号 |
H03M1/78 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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