| 摘要 |
PURPOSE:To enhance the anti-noise performance of the SCR element by lowering the current transmission rate between two anodes in the structure of two-way SCR. CONSTITUTION:Two SCR's are formed as prescribed using the N-type base substrate in common and then combined in two ways. Then anode terminals 18 and 19, cathode terminals 20 and 22 plus gate terminals 21 and 23 are installed respectively, and resistance 24 and 25 are connected between the gate and cathode terminal. The carrier injected from P-emitter 33 of element 26 flows to the emitters of the 2nd P-layer and element 27 in transmission ratio alpha1 and alpha2. Base current IB26 flowing through the PNP part of lamp function voltage application element 26 features the sum the transient current of the capacity of junction 32 and that of the PNP part of element 27, and IB26 xalpha1/(1-alpha1) flows to the PNP part of element 26 to produce voltage drop VGP at resistance 28. With approximation of the anode region, alpha2 increases with increment of IB26 and VGP. Thus, the anti-noise performance is lowered. |
