发明名称 |
Temperature compensated logarithmic circuit |
摘要 |
A log-amp or log-ratio circuit for producing a temperature-independent output signal corresponding to the logarithm of the ratio of a pair of input currents. The basic logarithm function is generated by a pair of opposed P-N junctions through which the respective input currents flow. Temperature compensation is effected by a circuit including a second pair of opposed P-N junctions which receive a PTAT current split between the junctions in accordance with a modulation factor proportional to the desired logarithmic function. The temperature-induced signal variations produced by the PTAT current source are equal and opposite to the temperature-induced signal variations produced in the first pair of P-N junctions, and a temperature-independent output signal is developed in accordance with the modulation factor applied to the PTAT current through the second pair of P-N junctions.
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申请公布号 |
US4604532(A) |
申请公布日期 |
1986.08.05 |
申请号 |
US19850694462 |
申请日期 |
1985.01.24 |
申请人 |
ANALOG DEVICES, INCORPORATED |
发明人 |
GILBERT, BARRIE |
分类号 |
G06G7/24;(IPC1-7):G06G7/12 |
主分类号 |
G06G7/24 |
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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