Tri State Buffer Ic. Inputs include clamp diodes which enable the use of current limiting resistors to interface inputs to voltages in excess of. The digital i o board figure 3 25 uses octal three state tri state buffers using 74hc240 logic ics that provide a digital buffer between the cpld and external digital logic circuitry.
74hct244 is an 8 bit buffer line driver with 3 state outputs. 6 27 september 2019 product data sheet 1. General description the 74hc2g125.
So a tri state buffer is just like a logic chip in that it offers high or low states but it also offers the additional state of high impedance.
If a fault in the external circuitry causes a situation that can damage the cpld e g electrical overstress then the 74hc240 logic ics will be damaged before the cpld. General description the 74hc2g125. A tri state buffer is a buffer that can be in 1 of 3 output states. Data sheet order now.
