| 摘要 |
PURPOSE:To supply constant potential within a normal operating range, and to apply high potential for a test to a load circuit in a manufacturing process by setting two reference potential determined by two formation means at proper values. CONSTITUTION:A second reference-potential generating means 1 is added between supply potential and a node N1. Potential at the node N1 is brought to supply potential when supply potential is lower than the total of the thresholds of each enhancement FETs Q1-Q4, and kept at a value slightly higher than the thresholds when supply potential is higher than the total of the thresholds, and potential at the node N1 rises at the same time as supply potential rises when the difference of supply potential and the total of the thresholds is higher than the total of the thresholds of FETs Q7-Q10. Output potential from a power circuit is made lower than the node N1 only by the threshold of a FET Q6 at all times by the FET Q6 using a gate as the node N1 and a drain as supply potential. According to the constitution, output potential is stabilized, and a load circuit can be protected while a burn-in test by applying high potential can also be executed. |
