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2022-09-24 23:18:44
MAX5940A-IEEE 802.3af PD-Powered Ethernet Interface Controller
The MAX5940A/MAX5940B provide a complete interface to a Powered Device (PD) compliant Ethernet system in compliance with the IEEE 802.3af standard. The MAX5940A/MAX5940B provide a Parkinson's disease signature detection, signature classification and integrated isolation switch with programmable inrush current control. These devices also feature power supply undervoltage mode lockout (UVLO) with extensive hysteresis, power good outputs. Parkinson's disease provides an integrated MOSFET for detection and classification during isolation. The MAX5940A/MAX5940B guarantee leakage currents of less than 10µA during the offset detection phase. Programmable current limit prevents high inrush currents from powering up. The device features power mode with wide hysteresis undervoltage lockout with long spike times to compensate for drops in twisted pair resistance, ensuring trouble-free transitions between detection, classification and power-on/-off stages. The MAX5940A provides an active high (PGOOD) drain output and a fixed UVLO threshold. The MAX5940B provides both active high (PGOOD) and active low (PGOOD) outputs, and has an adjustable UVLO threshold that is compatible with the 802.3af standard using default values. The MAX5940A/MAX5940B are designed to work with or without external diode bridges. The MAX5940A/MAX5940B are available in an 8-pin SO package and are specified over the extended temperature range of -40°C to +85°C