Cyclone® V Device Handbook: Volume 1: Device Interfaces and Integration

ID 683375
Date 10/18/2023
Document Table of Contents

5.4.7. Guideline: Observe Device Absolute Maximum Rating for 3.3 V Interfacing

To ensure device reliability and proper operation when you use the device for 3.3 V I/O interfacing, do not violate the absolute maximum ratings of the device. For more information about absolute maximum rating and maximum allowed overshoot during transitions, refer to the device datasheet.

Tip: Perform IBIS or SPICE simulations to make sure the overshoot and undershoot voltages are within the specifications.

Transmitter Application

If you use the Cyclone® V device as a transmitter, use slow slew rate and series termination to limit the overshoot and undershoot at the I/O pins. Transmission line effects that cause large voltage deviations at the receiver are associated with an impedance mismatch between the driver and the transmission lines. By matching the impedance of the driver to the characteristic impedance of the transmission line, you can significantly reduce overshoot voltage. You can use a series termination resistor placed physically close to the driver to match the total driver impedance to the transmission line impedance.

Receiver Application

If you use the Cyclone® V device as a receiver, use the on-chip clamping diode to limit the overshoot and undershoot voltage at the I/O pins.