
US Patent No: 4,994,730
Number of patents in Portfolio can not be more than 2000
Current source circuit with complementary current mirrors
Stats
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Feb 19, 1991
Issued date -
Dec 11, 1989
filing date -
07/448,498
serial no -
Expired
status
Importance
Abstract
A current source circuit capable of generating two currents of opposite polarities. In order to generate the two currents, the circuit comprises a current source stage including a current mirror and feeding a first output current and an inverter stage connected to the source stage and generating a second output current with opposite polarity with respect to the first. The inverter stage comprises a current mirror and a variable current source defining a control electrode. In order to eliminate the differences in the amplitude of the output currents, the inverter stage comprises a memory element connected to the control electrode so as to store an electrode controlling signal. Switch elements are furthermore interposed between the first output and the second output so as to short-circuit them during the trimming step so that the two output currents are equal to one another while the memory element memorizes the control signal. This signal remains stored during the normal operation of the circuit.
First Claim
Related Publications
International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
|---|---|---|---|
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| 4,717,869 Controlled current source apparatus for signals of either polarity | 11 | 1986 | |
| 4,740,743 Switchable bipolar current source | 14 | 1986 | |
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| 4,323,797 Reciprocal current circuit | 7 | 1980 | |
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| 4,706,013 Matching current source | 13 | 1986 | |
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| 4,618,816 CMOS .DELTA.V.sub.BE bias current generator | 23 | 1985 | |
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| 4,716,358 Constant current circuits | 9 | 1986 | |
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| 4,853,609 Distortion-free, opposite-phase current source | 8 | 1983 | |
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| 4,325,019 Current stabilizer | 10 | 1980 | |
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| 4,544,878 Switched current mirror | 11 | 1983 | |
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| 4,525,682 Biased current mirror having minimum switching delay | 19 | 1984 | |