| 摘要 |
PURPOSE: An external interface circuit is provided to have a resistant property to noise by having hysteresis in an on/off voltage of a switching circuit for sensing an external input. CONSTITUTION: An external Interface circuit(100) includes an input unit(10), an output unit(50), a switching circuit(30) connecting the input unit and the output unit. The external Interface circuit further include an input load(20) connecting the input unit and switching circuit and an output load(40) connecting the output unit and the switching circuit. The input unit includes a first input port(12) receiving power and a second input port(14) receiving an input signal having a logic level. The input load consists of a first node, a second node, and third and fourth nodes which are respectively connected to the first and the second node. |
