P89LPC935 Microcontroller Tutorial - gmitWEB

Interfacing Inputs to 5V Logic
• Although the supply voltage is lower, the I/O-pins are 5V-tolerant.
– i.e., the I/O stages cannot actively drive the outputs higher than the
supply voltage, but they may be pulled to 5V externally.
• The LPC935 inputs can be driven directly from the outputs of 5V logic
families.
• For a 3.3V power supply, the worst case Schmitt trigger input switching
levels are V IL
= 0.726V and V IH
= 2.31V.
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