MAX5971BEVKIT+ Maxim Integrated, MAX5971BEVKIT+ Datasheet - Page 11

• Manufacturer Part Number: MAX5971BEVKIT+
• Description: Power Management IC Development Tools
• Manufacturer: Maxim Integrated
• Series: MAX5971r

Specifications of MAX5971BEVKIT+

• Rohs: yes

PD-blocking diode D4 can be bypassed to reduce
power dissipation when AC-disconnect monitoring is
not required. The IC features an internal triangular-
wave oscillator for AC-disconnect detection and can be
bypassed to operate in DC-disconnect detection mode.
The internal oscillator must be shut down using jumper
JU6 if AC-disconnect detection is not required.
The output port also features a 600W overvoltage tran-
sient suppressor diode (D2) and decoupling capacitor
(C5) for transient protection at the output port. The EV
kit’s input port power rails (GND and VEE) are protected
by reverse-protection diode D5.
Test points and jumpers have been provided for voltage
probing and current measurements of the power circuit.
Additionally, since the GND is more positive than VEE
or RTN, use an isolated oscilloscope when probing
signals with respect to VEE or RTN. Yellow and green
LEDs on output module J2 indicate when the port’s
power is turned on and the PoE status, respectively.
The EV kit can also be reconfigured for interfacing with-
out connecting to an Ethernet system. Banana jacks
are included for the PSE GND and RTN output power
sources for this method of evaluation. Since the GND
is more positive than VEE or RTN, use an isolated
oscilloscope when probing signals with respect to
VEE or RTN.
The EV kit provides optical isolation for the I
2-wire interface, required by the IC operating as a slave
device, by optical couplers U3 and U4. The optically
isolated interface connects to a computer’s USB port
through the USB interface circuit. The EV kit’s I
compatible 2-wire interface can be reconfigured for
interfacing to a stand-alone microcontroller for isolated
(2-wire) or nonisolated (2-wire) serial operation. A sepa-
rate +3.3V power supply capable of supplying 35mA is
required for the IC’s nonisolated I
interface.
The optical isolation consists of optocoupler U3, which
provides galvanic isolation for the serial-interface clock
line (SCL) and serial-interface input data line (SDA) sig-
nals. Optocoupler U4 provides galvanic isolation for the
serial output and data line (SDA) and INT signals. The
SCL and SDA signals’ 2-wire serial interface are com-
bined on the isolated 2-wire side prior to feeding logic
buffers U5 and U6. The respective two-hole PCB pads
(OPTO_SCL, OPTO_SDA, OPTO_INT, OPTO_GND, and
OPTO_VCC) are used for 2-wire isolated stand-alone
operation. For nonisolated stand-alone 2-wire operation,
jumper JU8 shorting traces must be cut open and then
the SCL, SDA, INT, and 3_3V PCB jumper holes must be
connected to the microcontroller circuit. Note: The EV
kit’s provided 3_3V is at +3.3V. The OPTO_GND, GND,
and VEE planes are isolated by the optical couplers.
________________________________________________________________ Maxim Integrated Products 11
2
C-compatible 2-wire
2
C-compatible
2
C-
Since the GND is more positive than VEE or RTN, use
an isolated oscilloscope when probing signals with
respect to VEE or RTN.
The device slave address is configured by jumper JU7
and can be configured to one of four addresses: 0x40,
0x42, 0x44, or 0x46. Global address 0x60 is accepted
by the IC regardless of the jumper settings. See Table 9
for more information on setting the device slave address.
The EV kit features several jumpers to reconfigure the kit
for various PSE configurations, operating modes, and PD
requirements. Additionally, PCB pads and jumpers are
provided for connecting an external microcontroller and
setting the I
The EV kit features two jumpers to configure the IC’s
PSE PD classification mode, Class 0–Class 4 mode, or
high-power Class 5 mode. Jumper JU1 sets the IC’s
ILIM1 configuration and JU2 sets the ILIM2 configuration.
Table 1 lists the jumper options for the modes used to
detect a valid PD connected to the PSE Ethernet output
port. Refer to the MAX5971B IC data sheet for more infor-
mation on all classification modes available.
The EV kit features a 2-pin jumper (JU3) to enable or dis-
able the IC’s internal PWM driver for the LED pin. The IC’s
LED pin also serves as a port-status indicator using the
LED driver. The RJ45 connector (J2), providing data and
power at the output port, features 2 LEDs—a yellow LED
indicating that the EV kit is powered by -54V and a green
PSE port-status LED. Table 2 lists the LED driver jumper
options and Table 3 provides the port status. Refer to
the MAX5971B IC data sheet for more information on the
multifunction LED features.
The EV kit features a 2-pin jumper (JU4) to set the IC for
midspan or end-point operation. The PSE circuit must
also be reconfigured for operating in midspan or end-
point configuration.
Table 4 lists the jumper options and Table 5 lists the
PSE circuit resistor changes for the two configurations
of operation. In Table 5, installed resistors are 0I, 1206
surface-mount components. Refer to the MAX5971B IC
data sheet for more information on the configurations.
The EV kit features a 2-pin jumper (JU5) to set the IC’s ini-
tial startup legacy operational mode. In legacy mode, PD
signature capacitances up to 47FF (typ) are accepted.
Table 6 lists the jumper options. Refer to the MAX5971B
IC data sheet for more information.
Midspan/End-Point PoE Selection and Configuration
Evaluates: MAX5971B
Legacy High-Capacitance-Detection Operation
High-Power Class 5 and ILIM1/ILIM2 Selection
LED Driver PWM Enable and Port PoE Status
2
C slave address, respectively.
Jumper Selection