| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device that detects defects of a by-pass capacitor in real time.SOLUTION: An IC chip 1 includes an internal circuit 2 containing a CPU, a resistor 3, a load current increasing circuit 5 having a pulse generator 2a and a switch 4, and a ripple lower value detecting circuit 6. A power source terminal VD is connected to a direct-current power source 7 and a by-pass capacitor 8. The internal circuit 2 outputs a pulse from the pulse generator 2a and turns the switch 4 on. A current flows from the power source terminal VD via a resistor 3 so that a load current increases. If the by-pass capacitor 8 has a defect, a voltage decreases to lower than a threshold value and a detection signal is output to the internal circuit 2. This allows defect determination without lowering the voltage of the internal circuit 2 to a voltage at which the internal circuit is reset.SELECTED DRAWING: Figure 1 |
