18.3.1 Input Buffers

A 500K input buffers have the following features:

• CMOS voltage levels for 2.5 V and 3.3 V
• Optional pull-up resistor
• ESD protection circuitry
• Latch-up protection circuitry

Input Buffer Naming Conventions

The names for the input buffers are composed of up to four parts:

• A base name indicating the type of input buffer (IB for input with positive pad logic, IBN with negative pad logic)
• The number code 25 or 33 indicating a 2.5 or 3.3 voltage level
• A two character code indicating low power pad voltage (LP)
• An optional one character code (U) designating a pull-up resistor. When the buffer has no resistor, this code is omitted.