Current Monitoring and Current Limiting Accuracy
A word about current accuracies. All PSEs are very accurate in reading the port current. They need to measure classification currents with just a few mA of accuracy for example. So it is typically stated that the PSE IC from vendor X has better than ±3 percent accuracy. Or another has better than ±5 percent accuracy and so on. A lot of chip-design effort goes into accurate port I-V monitoring. After receiving this information, a specific IC may offer a cumulative timer for ICUT monitoring and so on (see previous section). That is why in Fig. 6.8, we have shown an ICUT monitoring band. The AT standard may not demand it, but such features are often required by major OEMs.
Current monitoring is ...
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