Embedded Computing Design

Previous articles have discussed several high data rate interfaces such as power-over-ethernet (PoE), USB, HDMI, DisplayPort, and eSATA. This article addresses protection schemes for low-speed interfaces. The discussion will also extend to the power line frequencies and present several protection methods for the AC and DC power supplies.

Accurate and reliable data transmission is the goal for all communication circuit designs. Electronics designers can choose from several communication protocols to address their application’s needs. To ensure minimal signal interference, maximize signal/noise, and optimize error correction algorithms, designers need to protect the input and output ports from damage.

Designers often neglect to consider that electrostatic discharge (ESD) and power-line induced transients can impact the electronic circuitry not directly connected to the AC power line. If they are designing devices with communication links, they need to ensure the data port circuitry is operating reliably at all times.