The MAX5988A evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board featuring an
Ethernet port, network powered-device (PD) interface
controller circuit for -57V supply rail systems. The EV kit
uses the MAX5988A IEEE® 802.3af/at-compliant network
PD interface controller in a 20-pin TQFN package with an
exposed pad. The IC is used in Power-over-LAN (PoL)
applications requiring DC power from an Ethernet network
port for PDs such as IP phones, wireless access nodes,
and security cameras.
The EV kit receives power from IEEE 802.3af/atcompliant
power-sourcing equipment (PSE). Refer to
the MAX5988A IC data sheet for PSE controllers. The
PSE provides the required -36V to -57V DC power over
an unshielded twisted-pair Ethernet network cable to the
EV kit’s RJ45 magnetic jack. The EV kit features a 1 x 1
gigabit RJ45 magnetic jack and two active full-wave
rectifiers (DM1, DM2) for separating the DC power
provided by an endspan or midspan Ethernet system.
The EV kit can also be powered by a wall adapter power
source. The EV kit provides PCB pads to accept the output
of a wall adapter power source. When a wall adapter
power source is detected, it always takes precedence
over the PSE source and allows the wall adapter to power
the EV kit.
The EV kit demonstrates the full functionality of the IC,
such as PD detection signature, PD classification signature,
inrush current control, input undervoltage lockout
(UVLO), and an integrated DC-DC step-down converter.
The integrated step-down converter operates at a fixed
215kHz switching frequency and is configured for a nonisolated
+5V DC output that can deliver 1.5A of current.
Warning: The EV kit is designed to operate with high voltages.
Dangerous voltages are present on this EV kit and
on equipment connected to it. Users who power up this EV
kit or power the sources connected to it must be careful to
follow safety procedures appropriately to work with highvoltage
electrical equipment.
Under severe fault or failure conditions, this EV kit may
dissipate large amounts of power, which could result in
the mechanical ejection of a component or of component
debris at high velocity. Operate this kit with care to avoid
possible personal injury.
Applications
- IEEE® 802.3af-Powered Devices
- IP Phones
- IP Security Cameras
- WiMAX® Base Stations
- Wireless Access Nodes
Obsolete
