| 摘要 |
PROBLEM TO BE SOLVED: To measure accurately an output voltage without impeding size increase or the degree of freedom of a design of a semiconductor device wherein linear regulators which are measuring objects are integrated. SOLUTION: A voltage VM2 of an output terminal of the second linear regulator 22 is measured by a voltmeter 17, and a voltage value of VIN-Vdrop=VM2 is determined. A load current IL is known beforehand because it is a constant current from a constant current source. Hereby, R=(VM2-VIN)÷IL is operated, and a contact resistance value R1=R2 is determined by a CPU 18. Furthermore, R2×IL=Vdrop is calculated, and the voltage Vdrop of a voltage drop portion by the contact resistance value R2 is determined. Vdrop is added to a voltage VM1 measured by a voltmeter 16, to thereby determine an actual output voltage VOUT1 of the linear regulator. COPYRIGHT: (C)2006,JPO&NCIPI
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