Maxim公司的MAX5952是网络供电（POE）-48V电源控制器，它和IEEE 02.3af与以前的IEEE 02.3at标准兼容。该器件提供了受电发现，分类，限流以及DC和AC负载断开，每个端口可提供的功率高达45W，每个端口的即时电流可通过I2C接口读出。可广泛应用在供电电源设备（PSE），交换/路由器以及跨接电源注入器。本解决方案提供了MAX5952的主要性能，方框图以及典型应用电路图以及几种POE系统应用电路图。

概述：
The MAX5952 is a quad -48V power controller designed for use in IEEE 02.3af-compliant/pre-IEEE
802.3at-compatible power-sourcing equipment (PSE). This device provides powered device (PD) discovery, classification, current limit, DC and AC load disconnect detections in compliance with the IEEE 802.3af standard. The MAX5952 is pin compatible with MAX5945/ LTC4258/LTC4259A PSE controllers and provides additional features.
The MAX5952 features high-power mode that provides up to 45W per port. The MAX5952 provides instantaneous readout of each port current through the I2C interface. The MAX5952 also provides high-capacitance detection for legacy PDs.

The device features an I2C-compatible, 3-wire serial interface, and is fully software configurable and programmable. The class-overcurrent detection function enables system power management to detect if a PD draws more than the allowable current. The MAX5952’s extensive programmability
enhances system flexibility, enables field diagnosis, and allows for uses in other applications.
The MAX5952 provides four operating modes to suit different system requirements. Auto mode allows the device to operate automatically without any software supervision. Semi-automatic mode automatically detects and classifies a device connected to a port after initial software activation,
but does not power up that port until instructed to by software. Manual mode allows total software control of the device and is useful for system diagnostics. Shutdown mode terminates all activities and securely turns off power to the ports.

The MAX5952 provides input undervoltage lockout (UVLO), input undervoltage detection, a load-stability safety check during detection, input overvoltage lockout, overtemperature detection, output voltage slewrate limit during startup, power-good status, and fault status. The MAX5952’s programmability includes startup timeout, overcurrent timeout, and load-disconnect detection timeout.
The MAX5952 is available in a 36-pin SSOP package and is rated for both extended (-40°C to +85°C) and upper commercial (0°C to +85°C) temperature ranges.
主要特性：
IEEE 802.3af Compliant/Pre-IEEE 802.3at Compatible
Instantaneous Readout of Port Current Through I2C Interface
High-Power Mode Enables Up to 45W Per Port
High-Capacitance Detection for Legacy Devices
Pin Compatible to MAX5945 and LTC4258/LTC4259A
Four Independent Power-Switch Controllers
PD Detection and Classification
Load-Stability Safety Check During Detection
Supports Both DC and AC Load Removal Detections
I2C-Compatible, 3-Wire Serial Interface
Current Foldback and Duty-Cycle-Controlled Current Limit
Open-Drain INT Signal
Direct Fast Shutdown Control Capability

应用：
Power-Sourcing Equipment (PSE)
Switches/Routers
Midspan Power Injectors
图1。MAX5952方框图：



图2。MAX5952应用电路图：



图3。 PoE 系统方框图（1）。



图4。 PoE 系统方框图（2）。



图5。 用于VDIG 的-48V 到 +3.3V (300mA) 升压转换器解决方案



图6。典型应用电路（1）（没有AC负载遥控检测）



图6。典型应用电路（2）（带AC负载遥控检测）

详情请见MAX5952数据表：

http://datasheets.maxim-ic.com/en/ds/MAX5952.pdf

来源：中电网