| 摘要 |
PURPOSE:To make AD converters in high density by constituting comparators for AD conversion with I<2>L and integrating the same with the logic circuits constituted with the I<2>L. CONSTITUTION:An N type layer 2 is epitaxially grown on an N<+> type semiconductor substrate 1 and mutually isolated four P type regions 3, 4, 5, 8 are diffusion- formed here. Next, an N<+> type region 6 and a P<+> type region 7 are provided in the region 5 and an N<+> type region 9 in the region 8, respectively. Thereafter, the regions 7 and 9 are electrically connected and in this state the substrate 1 is grounded and signal current and reference current are respectively supplied to the regions 3 and 4. Compared output is drawn out from the region 6. If in this way the transistors Q1 thru Q4 are constituted, the collector output of the transistor Q4 becomes of high level when hFE IB2>IC2, and becomes of low level when converse. Hence, if the weight of hFE is beforehand given to the input current of the transistor Q1, the comparing operation is completed. |
