| 摘要 |
PROBLEM TO BE SOLVED: To efficiently reduce spike voltage which is produced with the on/off operation of switching of a switching regulator. SOLUTION: A spike noise reduction device comprises a spike noise detection circuit 3, which detects when spike noise superposed on the output of the switching regulator exceeds the threshold; a noise reduction element for reducing spike noise, externally started and comprising an additional transistor NMOS2, which is higher in on resistance than a driver transistor NMOS1 for switching of the switching regulator and is less prone to produce spike noise; and a timing adjustment circuit 2 and a driver switch circuit 6 which start the additional transistor NMOS2, when the spike noise detection circuit 3 detects spike noise which is outside of the threshold. COPYRIGHT: (C)2004,JPO
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