METHOD FOR PROTECTING TRI-STATE GATE

摘要

PURPOSE:To prevent destruction of a tri-state gate at the time of conducting electricity by providing a decoder circuit between enable logic and a tri-state gate. CONSTITUTION:Enable logic 1-1-1-3 are respectively connected to inputs C, B, and A of a decoder 2, outputs Y4, Y2 and Y1 of the decoder 2 are respectively connected to an enable input of the tri-state gates 3-1-3-3. The outputs of the tri-state gates 3-1-3-3 are connected in common to internal bus. The decoder 2 prevents destruction of the entire tri-state gate 3-1-3-3 which are connected to the common internal bus line at the time of conducting electricity under high impedance conditions or by enabling only one tri-state gate to prevent destruction of the tri-state gate 3-1-3-3 which threaten to occur at the time of conducting electricity.