MAX77950 Evaluation Kit
Evaluates: MAX77950
General Description
The MAX77950 evaluation kit (EV kit) is a fully assembled
and tested PCB that evaluates the MAX77950 advanced
wireless power receiver IC. The IC meets the specification
requirements for WPC low-power (v1.2) and PMA SR1
(v2.0) communication protocols and operates using near-
field magnetic induction when coupled with WPC or PMA
transmitters, providing up to 12W of output power.
The EV kit comes with a planar coil to receive or transmit
power wirelessly, as well as Windows
®
-based software
that provides a graphical user interface (GUI) to evaluate
the functions of the device.
Quick Start
Required Equipment
●
MAX77950 EV kit
●
Wireless power transmitter with WPC/PMA
compliance
●
Micro-USB cable
●
Digital multimeter (DVM)
●
Windows-based PC
●
Optional: DC power supply
●
Optional: Electronic load
Note:
In the following sections, software-related items are
identified by bolding. Text in
bold
refers to items directly
from the EV kit software. Text in
bold and underlined
refers to items from the Windows operating system.
Benefits and Features
●
Ready-to-Go EV Kit with Receiver Coil
●
Multiple Test Points to Measure Output Voltage
(V
OUT
), Rectifier Output Voltage (V
RECT
),
and AC Voltage
●
Graphical User Interface (GUI) Software for the
Multifunction Test
●
LED Indication to Monitor Operation
●
RoHS Compliant
●
Proven PCB Layout
●
Fully Assembled and Tested
MAX77950 EV Kit Photo
Ordering Information
appears at end of data sheet.
Windows is a registered trademark and registered service mark
of Microsoft Corporation.
319-100007; Rev 0; 3/17
MAX77950 Evaluation Kit
Evaluates: MAX77950
Procedures
The EV kit is fully assembled and tested. The following
steps are used to verify board operation.
6)
7)
8)
Install the EV Kit GUI
The EV kit GUI allows the user to communicate with the
EV kit. The GUI connects to the EV kit through an I
2
C and
USB interface to monitor and control the IC by changing
the register-related functions such as FOD coefficient,
V
RECT
target for WPC/PMA, and LDO output voltage.
1)
Visit
www.maximintegrated.com/evkitsoftware
to
download the latest version of the EV kit software,
MAX77950_EVKIT_GUI_1.70207.0D-x86.zip. Save
the EV kit software to a temporary folder and uncom-
press the file.
Unzip and run the execution file and follow the in-
structions to finish the installation.
Ensure that the EV kit has the desired jumper set-
tings, as shown in
Table 1.
Connect to a PC using the Micro-USB cable (see the
MAX77950 EV Kit Photo).
Turn on the WPC/PMA transmitter to provide power
to the EV kit.
Place the EV kit on the transmitter and align properly.
Check that the power-good indicator LED (DS1)
is on.
Launch the EV kit GUI. Press
Connect
under the
De-
vice
menu to initiate the link with the EV kit as shown
in
Figure 1.
PeerPower
Follow the steps below to operate the EV kit in PeerPower
TM
mode:
9) Disconnect all power supplies from the EV kit.
10) Make a jumper connection on P2P_EN (J2) to VIO
pins (1-2) to enable PeerPower mode.
11)
Set J101 to pins 1-2 if an external voltage source is
used to supply 1.8V to VIO; otherwise, set to pins 2-3
to use the on-board 1.8V.
12) Preset a DC power supply to 5V (if you choose to use
an external source to VIO, preset the other DC power
supply to 1.8V).
13) Connect the 5V DC power supply to V
OUT
and 1.8V
to E_VIO (see the
MAX77950 EV Kit Photo)
14) Turn on the power supply.
15) The EV kit is now ready to operate as a transmitter.
*For VIO to use on-board 1.8V from LDO (U103), connect
to a 5V source through the Micro-USB cable (J4).
2)
Startup
3)
4)
5)
Table 1. Default Jumper Settings
JUMPER
J1
NODE OR FUNCTION
WP_EN
SHUNT POSITION
1-2
2-3*
1-2
J2
J3
J101
*Default
position.
P2P_EN
WP_DET
VIO
2-3
OPEN*
1-2*
1-2
2-3*
The device is disabled.
The device is enabled.
Connecting P2P_EN to VIO.
Not in use.
PeerPower is disabled.
Connect WP_DET to LED.
An external source (1.8V) supplies VIO.
On-board 1.8V LDO (U103) supplies VIO.
FUNCTION
PeerPower is a trademark of Maxim Integrated Products, Inc.
www.maximintegrated.com
Maxim Integrated │
2
MAX77950 Evaluation Kit
Evaluates: MAX77950
Detailed Description of Software
The MAX77950 EV kit GUI (Figure
2)
is a convenient
tool to control the IC through the I
2
C communication.
The GUI consists of six tabs, and each one combines the
related functions. For example, in the
RXMODE
tab, the
registers related to receiver mode of the IC are shown
and controlled by using a slidebar if they are writable
registers. The registers load the data from OTP when the
IC restarts. The current register values are presented by
clicking the
Read
button.
Figure 1. MAX77950 EV Kit GUI (Device Connect)
Figure 2. MAX77950 EV Kit GUI (STATUS Tab)
www.maximintegrated.com
Maxim Integrated │
3
MAX77950 Evaluation Kit
Evaluates: MAX77950
RXMODE
In the
RXMODE
tab, the registers associated with the
receiver mode function can be examined. Some registers
are writable and can be changed by the user.
●
The LDO output voltage (V
OUTSET
) and the LDO cur-
rent limit (LDO_ILMITSET) can be changed by the
user. As seen in box #1 in
Figure 3,
the default value
of V
OUT
is 5V.
• Click
Read
to ensure that the current value in the
register is properly displayed.
• Adjust the slide bar to set the value desired and
send the changes to the IC by clicking the
Write
button next to the slide bar.
• Repeat the steps to change the LDO current limit
(box #2).
The end-power-transfer (EPT) packet can be sent
manually by the GUI along with the reason for EPT.
The reason for EPT must be set before sending the
EPT packet (Figure
3).
• By sliding the cursor, the reason for EPT can be se-
lected. Click
Write
to fix the values of EPT reason
on the EPT_REASON register (box #3).
•
To send the EPT packet, toggle the switch next to
the
Send EPT
in box #4 and then click the
Write
button (#5) in the
RX_COM
group box.
●
The proprietary packet (PPP) can also be sent by the
IC. The user can practice sending a PPP using the
GUI. In WPC specifications, several PPPs are de-
fined and they have a message length up to 20 bytes.
The IC supports the PPP that supports up to 5 bytes
of the message.
The following example procedure is for sending a PPP
with the GUI:
●
●
Decide on the PPP with the designed message length
(in this example, it is 3)
Write the PPP_HEADER as 0x38 because the PPP
that starts with the 0x38 header is defined to have 3
bytes of the message in the specification (box #6).
Write 3 bytes of message in the RX_DATA_VAL-
UE0/1/2 (box #7).
Toggle on the SEND_RX_DATA bit (box #8) and send
by clicking the
Write
button (box #5).
●
●
●
Figure 3. MAX77950 EV Kit GUI (RXMODE Tab)
www.maximintegrated.com
Maxim Integrated │
4
MAX77950 Evaluation Kit
Evaluates: MAX77950
FOD-RX
●
●
As required by the WPC specifications, foreign object
detection (FOD) is a function of the IC. The coefficient for
the FOD can be modified in the
FOD-RX
tab (Figure
4).
Click the
FOD-RX
tab in the left sidebar. Read the
registers to see the current FOD coefficients.
Adjust the coefficients as desired by dragging the cur-
sor on the slide bars. Then, click the
Write
button to
send the changes to the IC (to decide the FOD coef-
ficients, refer to the MAX77950 IC data sheet).
Figure 4. MAX77950 EV Kit GUI (FOD-RX Tab)
www.maximintegrated.com
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