Analog Devices MAX77831, Manual

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MAX77831 Evaluation Kit
Evaluates: MAX77831
EV Kit Default Configuration
With the default jumper settings listed in Table 1 and the
EV kit component values of R
SEL
(R9) = 0Ω, R
TOP
(R10)
= 0Ω, and R
BOT
(R11) = OPEN, the MAX77831 EV kit is
configured with the following settings:
● Internal Feedback
● Switching Current Limit = 7.0A
● I
2
C Slave Address (7-bit) = 0x66
● Switching Frequency = 1.8MHz (adjustable only
through the I
2
C)
● I
2
C Line Connected to MAXUSB_INTERFACE#
See the EV Kit Hardware section to change the EV kit
configuration.
Quick Start
Required Equipment
● MAX77831 EV Kit
● Adjustable DC Power Supply
● A 1.8V DC Power Supply
● Digital Multi-Meters
● Electronic Load
● MAXUSB_INTERFACE# for I
2
C Serial Interface
(Optional)
● USB Type-A to Micro-USB Cable (Optional)
● Windows-based PC with MAX77831 EV Kit GUI
(Optional)
Procedure
The EV kit is fully assembled and tested. Perform the
following steps to verify board operation. Use twisted
wires of appropriate gauge (20 AWG) that are as short as
possible to connect the load and power sources.
1) Ensure that the EV kit has the correct jumper settings,
as shown in Table 1 .
2) Connect a DVM to the INS and PGND1S sense pins
to measure input voltage.
3) Connect a DVM to the OUTS and PGND2S sense
pins to measure output voltage.
4) Apply a power supply set to 1.8V (100mA current lim -
it) across VIO and GND terminals of the EV kit. Turn
on the power supply.
5) Apply a power supply set to 0V (1.5A current limit)
through an ammeter across the IN and PGND1 ter -
minals of the EV kit. Turn the supply on and increase
the voltage to 7.6V.
6) Confirm the DVM connected to OUTS and PGND2S
reads the default output voltage of the EV kit (5V).
Confirm the ammeter reads the expected input supply
current (about 12mA).
7) Now that the EV kit is confirmed working, short out
the series ammeter and increase the current limit on
the power supply connected across IN and PGND1.
Connect an electronic load across the OUT and
PGND2 terminals to evaluate the performance of the
MAX77831 buck-boost regulator.
The next steps of the procedure use the EV kit GUI and
MAXUSB_INTERFACE# to evaluate the MAX77831’s I
2
C
serial interface. If evaluation of the I
2
C serial interface is not
required, you may skip the following steps. The EV kit in -
cludes on-board 2.2kΩ pullup resistors (R4 and R7) to V
IO
.
8) Install GUI software. Visit the product webpage at
https://www.maximintegrated.com/products/
MAX77831WEVKIT and navigate to Design Re -
sources to download the latest version of the EV kit
software. Save the EV kit software installation file to
a temporary folder and decompress the ZIP file. Run
the .EXE file and follow the on-screen instructions to
complete installation.
Table 1. Default Shunt Positions and Jumper Description
* Default position
JUMPER NODE
SHUNT
POSITION
FUNCTION
J1 EN
1-2* Connects EN to V
IO
(logic-high, enables MAX77831).
2-3 Connects EN to AGND (logic-low, disables MAX77831).
J2 SDA
1-2* Pulls SDA up to V
IO
through R7 (2.2kΩ).
2-3 Connects SDA to AGND.
J3 MAXUSB_VIO 1-2* Connects MAXUSB_INTERFACE# V
IO
to EV kit V
IO
.
J4 MAXUSB_SDA 1-2* Connects MAXUSB_INTERFACE# SDA to EV kit SDA.
R3 MAXUSB_SCL 0Ω installed* Connects MAXUSB_INTERFACE# SCL to EV kit SCL.