ESD ratings are very important for interface ICs, because the bus pins typically connect to an exposed port on a piece of equipment. Simply attaching a cable may induce an ESD event that can destroy an unprotected IC. Unlike the RS-232 market where a part number with an ”E” suffix typically indicates the more robust IEC61000 ESD protection, the “E” suffix on RS-485 devices may indicate human body model, or IEC61000 based protection. Thus to suggest a good cross for a customer’s device, the user must first determine to which ESD standard the competitor device is tested. Luckily, most high ESD IC datasheets call out the protection standard in the features or description sections on the front page. Renesas offers both HBM and IEC61000 specified RS-485 ICs, so it is important to ensure that the user recommend the proper ESD cross. Renesas' older high ESD RS-485 families with prefixes of ISL8 or ISL4 are all specified for HBM ESD. Most – but not all – of the newer families specify ESD to IEC61000. The two most ESD robust families are the ISL315XE for 5V supplies, and the ISL317XE for 3.3V supplies. If the Renesas cross reference tool lists their part as a PP or drop-in replacement, then the ESD level is as good or better than the competitor’s part.