| 摘要 |
PURPOSE:To provide a protective circuit with high performance making it compact and hard to latch-up by a method wherein the second P layer is formed near the first P layer connected to external terminal constituting a horizontal N-P-N transistor utilizing N layer as a base. CONSTITUTION:An external terminal 1 is connected to P layer 3 of N type substrate 11 by the first connector 2 further connecting to a wiring material 5 through the second connector 4 while the wiring material 5 is connected to N layer 8 in P layer 7 through third connector 6. The P layer 7 extended to adjoin P tyoe diffusion resisting layer 3 is provided with potential-sustaining P layer 10. On the other hand, another potential-sustaining N layer 9 is provided around the overall protective circuit. A horizontal P-N-P element 15 is formed by layer 3-substrate 11-layer 7 and when the external terminal 1 is supplied with positive high voltage, the current capacity is multiplied by hFE improving the protective performance. The overall circuit may be made compact by means of making the layer 9 approach to the layer 7 since the carrier from the layer 3 may be caught by the adjoining layer 7. |
