19-6349; Rev 0; 5/12
MAX5986A Evaluation Kit
Evaluates: MAX5986A
General Description
The MAX5986A 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 MAX5986A IEEE
M
802.3af/at-compliant network
PD interface controller in a 16-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/at-compliant
power-sourcing equipment (PSE). Refer to the MAX5952,
MAX5965A/MAX5965B, and MAX5980 IC data sheets 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 (N101 and N102) for separat-
ing 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 out-
put 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 signa-
ture, inrush current control, input undervoltage lockout
(UVLO), and an integrated DC-DC step-down converter.
The integrated step-down converter operates at a fixed
275kHz switching frequency, and is configured for a non-
isolated +5V DC output that can deliver 768mA 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 high-voltage 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.
S
PoE Classification 1
S
-36V to -57V Input Range
S
Demonstrates an Integrated 3.84W Step-Down
DC-DC Converter
S
+5V Output at 768mA
S
Inrush Current Limit of 49mA (typ)
S
Evaluates Endspan and Midspan Ethernet
Systems
S
Simplified Wall Adapter Interface
S
Proven PCB Layout
S
Fully Assembled and Tested
Ordering Information
appears at end of data sheet.
Features
S
IEEE 802.3af/at-Compliant PD Interface Circuit
Component List
DESIGNATION
AUX, GND, LX,
VCC, VDRV
C1, C3
QTY
5
DESCRIPTION
Miniature white test points
0.1FF
Q10%,
100V X7R ceramic
capacitors (0603)
Murata GRM188R72A104K
1FF
Q10%,
100V X7R ceramic
capacitors (1206)
Murata GRM31CR72A105K
0.1FF
Q10%,
50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
1FF
Q10%,
25V X7R ceramic
capacitor (0603)
Murata GRM188R71E105K
22FF
Q10%,
10V X7R ceramic
capacitors (1206)
Murata GRM31CR71A226K
10FF
Q20%,
80V aluminum
electrolytic capacitor
(6.3mm x 7.7mm)
Panasonic EEE-FK1K100XP
Not installed, ceramic capacitor
(0402)
2
C2, C14
2
C4, C6
2
C5
1
C7, C10, C15
3
C8
1
C9
IEEE is a registered service mark of the Institute of Electrical
and Electronics Engineers, Inc.
0
_________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX5986A Evaluation Kit
Evaluates: MAX5986A
Component List (continued)
DESIGNATION
C11
C12, C13
D1
D2, D101–D104
D5
D6
QTY
0
0
0
5
0
0
DESCRIPTION
Not installed, ceramic capacitor
(0805)
Not installed, ceramic capacitors
(0603)
Not installed, Schottky diode
(SMB)
100V, 2A Schottky diodes (SMB)
Diodes Inc. B2100
Not installed, zener diode
(SOD323)
Not installed, transient voltage
suppressor (SMB)
8.2V
Q5%,
200mW zener diodes
(SOD323)
Fairchild MM3Z8V2C
47FH, 1.15A inductor
(8.3mm x 8.3mm)
Sumida CDRH8D28NP-470NC
Not installed, common-mode
chokes (9.5mm x 6mm)
100V, 3.5A dual n-channel
MOSFETs (8 SO)
Fairchild FDS89141
DESIGNATION
R1
R2
R3
R4
R5
R12
R13
R14
R19
R20–R23
R101–R104
R105–R108
RJ45
QTY
1
1
1
1
1
1
1
1
0
4
4
4
1
DESCRIPTION
0I
Q5%
resistor (0402)
100kI
Q1%
resistor (0402)
1kI
Q1%
resistor (0603)
2.49kI
Q1%
resistor (0402)
24.9kI
Q1%
resistor (0402)
10I
Q1%
resistor (0603)
10I
Q1%
resistor (0402)
7.5kI
Q1%
resistor (0402)
Not installed, resistor (0402)
0I
Q5%
resistors (0603)
499kI
Q1%
resistors (0402)
49.9kI
Q1%
resistors (0402)
RJ45 MagJack 1G-Ethernet,
802.3af/at standard
Bel Fuse Inc. 0826-1X1T-M1-F
PD with integrated DC-DC
converter (16 TQFN-EP*)
Maxim MAX5986AETE+
PCB: MAX5986A EVALUATION
KIT
D105–D108
4
L1
1
U1
1
L2, L3
0
—
*EP
= Exposed pad.
1
N101, N102
2
Component Suppliers
SUPPLIER
Bel Fuse Inc.
Diodes Incorporated
Fairchild Semiconductor
Murata Electronics North America, Inc.
Panasonic Corp.
Sumida Corp.
PHONE
201-432-0463
805-446-4800
888-522-5372
770-436-1300
800-344-2112
847-545-6700
www.belfuse.com
www.diodes.com
www.fairchildsemi.com
www.murata-northamerica.com
www.panasonic.com
www.sumida.com
WEBSITE
Note:
Indicate that you are using the MAX5986A when contacting these component suppliers.
_________________________________________________________________
Maxim Integrated Products
2
MAX5986A Evaluation Kit
Evaluates: MAX5986A
Quick Start
•
•
•
•
MAX5986A EV kit
Required Equipment
An IEEE 802.3af/at-compliant PSE and a Category
5e Ethernet network cable
-48V, 1A capable DC power supply
Voltmeter
The EV kit can also accept power from a wall adapter
power source. When a wall adapter power source is
detected between the WAD_IN and WAD_GND PCB
pads, the IC’s internal isolation switch disconnects VCC
from VDD, which allows the wall adapter to supply power
to the EV kit.
The EV kit demonstrates the full functionality of the IC
such as PD detection signature, PD classification signa-
ture, inrush current control, and UVLO. Resistor R5 sets
the PD detection and classification signatures. The EV kit
is set to a Class 1 PD by resistor R5.
The EV kit’s integrated DC-DC step-down converter is
configured for a nonisolated output voltage of +5V and
provides up to 768mA at the output while achieving up
to 86.68% and 90.22% efficiencies at +36V and +12V
input, respectively. The integrated step-down converter
operates at a fixed 275kHz switching frequency.
The EV kit is fully assembled and tested. Follow the steps
below to verify board operation.
Caution: Do not turn on
the power supply until all connections are completed.
1)
Use one of the following methods to power the EV kit:
a.
If network connectivity is required:
Connect a
Category 5e Ethernet network cable from the EV
kit input port RJ45 connector to the correspond-
ing PSE Ethernet LAN connection that provides
power to the EV kit.
b.
If network connectivity is not required:
Connect
a -48V DC power supply between the V- and V+
PCB pads on the EV kit. Connect the power-
supply positive terminal to the V+ PCB pad and
the negative terminal to the V- PCB pad.
2)
3)
Activate the PSE power supply or turn on the external
DC power supply.
Using a voltmeter, verify that the EV kit provides +5V
across the OUT and VSS PCB pads.
Hardware Connections
The EV kit can also accept power from a wall adapter
power source. Use the WAD_IN (0V) and WAD_GND
(-10V to -57V) PCB pads to connect the wall adapter
power source. The wall adapter power source operating-
voltage range must be within +10V to +57V for the EV kit.
When the wall adapter power source is above +10V it
always takes precedence over the PSE source. Once the
wall adapter power source is detected, the IC’s internal
isolation switch disconnects VCC from VDD. The wall
adapter power is supplied to VCC (through diode D2)
and VSS. Once it takes over, the classification process
is disabled.
When the wall adapter power source is below +8.5V, the
PSE provides power through the IC’s VSS. Diode D2 pre-
vents the PSE from back-driving the wall adapter power
source when it is below +8.5V.
The EV kit operates up to a -57V supply with a turn-on
UVLO threshold (V
ON
) at -37.6V and a turn-off UVLO
threshold (V
OFF
) at -30.0V. When the input voltage is
above V
ON
, the EV kit is enabled. When the input voltage
goes below V
OFF
, the EV kit is disabled.
Wall Adapter Power Source
(WAD_IN, WAD_GND)
Detailed Description of Hardware
The MAX5986A EV kit features an Ethernet port and net-
work PD interface controller circuit for -57V supply rail
systems. The EV kit contains a MAX5986A IEEE 802.3af/
at-compliant network PD interface controller in a 16-pin
TQFN-EP package. The IC is used in PoL applications
for powering PDs from an unshielded twisted-pair (UTP)
Ethernet Category 5e network cable and PSE port using
endspan or midspan Ethernet systems.
The EV kit receives power from an IEEE 802.3af/at-
compliant PSE and a UTP cable connected to the EV
kit’s RJ45 magnetic jack. The EV kit uses a 1 x 1 gigabit
RJ45 magnetic jack and two active full-wave bridge
power rectifiers to separate the -57V DC power sent by
the PSE. The EV kit can accept power from an endspan
or midspan PSE network configuration.
Undervoltage Lockout (UVLO)
_________________________________________________________________
Maxim Integrated Products
3
MAX5986A Evaluation Kit
Evaluates: MAX5986A
Figure 1. MAX5986A EV Kit Schematic
_________________________________________________________________
Maxim Integrated Products
4
MAX5986A Evaluation Kit
Evaluates: MAX5986A
1.0”
Figure 2. MAX5986A EV Kit Component Placement Guide—Component Side
1.0”
Figure 3. MAX5986A EV Kit PCB Layout—Component Side
1.0”
Figure 4. MAX5986A EV Kit PCB Layout—PGND Layer 2
_________________________________________________________________
Maxim Integrated Products
5
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