| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit which switches at a high speed when eliminating high-frequency noise by a target cut-off frequency, and when passing through a low-pass filter in a current mirror circuit. SOLUTION: The low pass filter comprising resistors and capacitors, is connected via a voltage follower between control electrodes of an input transistor and an output transistor which comprise the current mirror, and a switch composed of transistors for selecting the case to by-pass the low-pass filter and the case to pass through the low-pass filter. By this means, it is possible to constitute the low pass filter which is not influenced by the input load, and also it is possible to switch in high speed the case for eliminating high-frequency noise by means of the low-pass filter and the case for by-passing the low-pass filter. COPYRIGHT: (C)2005,JPO&NCIPI
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