MAX77874 Evaluation Kit
Evaluates: MAX77874
General Description
The MAX77874 evaluation kit (EV kit) is a fully assembled
and tested printed circuit board (PCB) that demonstrates
the MAX77874. The EV kit allows for easy evaluation of
the MAX77874 quad-phase core buck regulator by pro-
viding access to the I
2
C bus and including an on-board
load pulse generator circuit. The EV kit also serves as a
guide for layout and design with the MAX77874.
Windows
®
-based software provides a user-friendly graph-
ical interface as well as a detailed register-based interface
to exercise the features of the MAX77874.
Features
●
Quad-Phase Core Buck Regulator
• Test Points for Both Local Output and Remote
Sense
• Exercise DVS with Simple GUI Tool
●
On-Board Load Pulse Generator Circuit
• Adjust Load Current with Parallel Resistor Loads
• Easily Perform Load Transients with the Press of
a Button
●
I
2
C Interface
• Access Through USB Port or Directly Through
SDA and SCL Test Points
●
Lead-Free and RoHS Compliant
●
Software GUI and Command Module
●
Assembled and Tested
Ordering Information
appears at end of data sheet.
MAX77874 EV Kit
Windows is a registered trademark and registered service mark
of Microsoft Corp.
19-8748; Rev 0; 12/16
MAX77874 Evaluation Kit
Evaluates: MAX77874
EV Kit Detail
Figure 1. MAX77874 EV Kit Top View
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MAX77874 Evaluation Kit
Evaluates: MAX77874
Figure 2. MAX77874 Top View Main Components
Quick Start
4)
5)
6)
Follow this procedure to become familiar with the EV kit.
Connect a micro-USB cable between the EV kit’s J4
and your Windows-based PC.
Turn on the power supply.
Open the GUI and press the
Connect
button in
the upper-left corner. If the
Connect
button does
not appear, first press
File,
then click
Show Menu
Shortcuts.
Wait for the device to respond, and in the
Synchronize
window, press the
Read and Close
button.
Measure the output voltage with the DVM. Ensure it
is 0.9V.
Check that the quiescent current on the ammeter is
approximately 400μA.
In the GUI, move the slider for
Output Voltage
(DVS
= 0) to 1100mV and click the
Write
button. Ensure
that the output now reads 1.1V.
Required Equipment
●
MAX77874 EV kit
●
Power supply
●
Ammeter
●
DVM
●
Micro-USB cable
●
GUI
●
Windows-based PC
7)
8)
9)
Procedure
1)
Install GUI software. Visit
www.maximintegrated.
com/evkitsoftware
to download the latest version
of the EV kit software. Save the EV kit software to a
temporary folder and unzip the ZIP file.
Ensure that shunts are installed on the jumpers per
Table 1.
Apply a 3.7V supply (set for 100mA current limit)
through an ammeter (set for 100mA range) across
the VSYS and PGND terminals of the EV kit.
2)
3)
10) Note that there is a shunt connected to J200. Press
and hold SW200, and check the ammeter reads
approximately 23mA. This verifies that the pulse
generator is working properly.
11) This concludes the Quick Start procedure. Users are
now encouraged to explore the device and its regis-
ter settings with the GUI.
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MAX77874 Evaluation Kit
Evaluates: MAX77874
Table 1. Default Shunt Positions and Jumper Descriptions
REFERENCE
DESIGNATOR
J2
J3
J100
J101
J200
J201
J202
J203
J204
J205
J206
J207
J208
J209
J210
J211
J212
J213
J214
J215
J216
J217
J218
DEFAULT
POSITION
2-3
1-2
—
1-2
1-2
—
—
—
—
—
—
1-2
—
1-2
—
—
—
—
—
1-2
—
—
1-2
1-2: Connect DVS to VIO.
2-3: Connect DVS to GND.
1-2: Connect EN to VIO.
2-3: Connect EN to GND.
Do not connect shunts to J100.
1-2: Connect VIO to the 3.3V EV kit logic rail.
2-3: Connect VIO to the 1.8V EV kit logic rail.
Connect a 0.5Ω resistor in the load pulse generator circuit from VOUT to Q200.
Connect a 0.5Ω resistor in the load pulse generator circuit from VOUT to Q200.
Connect a 0.5Ω resistor in the load pulse generator circuit from VOUT to Q200.
Connect a 0.5Ω resistor in the load pulse generator circuit from VOUT to Q200.
Connect a 0.5Ω resistor in the load pulse generator circuit from VOUT to Q200.
Connect a 0.5Ω resistor in the load pulse generator circuit from VOUT to Q200.
Connect a 0.5Ω resistor in the load pulse generator circuit from VOUT to Q200.
Connect the 5V USB rail to the supply of the 555 timer of the load pulse generator circuit.
Connect a shunt to select the 100µs period for the pulse generator.
Connect a shunt to select the 1ms period for the pulse generator.
Connect a shunt to select the 10ms period for the pulse generator.
Connect a shunt to select the 100ms period for the pulse generator.
Connect a shunt to select the 1% duty cycle setting for the pulse generator.
Connect a shunt to select the 1.5% duty cycle setting for the pulse generator.
Connect a shunt to select the 2% duty cycle setting for the pulse generator.
Connect a shunt to select the 3% duty cycle setting for the pulse generator.
Connect a shunt to select the 5% duty cycle setting for the pulse generator.
Connect a shunt to select the 7% duty cycle setting for the pulse generator.
1-2: Drive the load FET with the pulse generator circuit.
2-3: Drive the load FET externally with EXT_PLS_IN.
FUNCTION
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MAX77874 Evaluation Kit
Evaluates: MAX77874
Software
The graphical user interface (GUI) software allows for
quick, easy, and thorough evaluation of the MAX77874.
The GUI is designed to be very simple, with all necessary
controls on a single page. See
Figure 3
for a screenshot
of the GUI upon first opening.
Windows Drivers
Upon connection of a micro-USB cable between your PC
and the EV kit for the first time, wait a few minutes for
Windows to automatically install the necessary drivers.
Graphical User Interface Details (GUI)
Installation
Visit
www.maximintegrated.com/evkitsoftware
to
download the latest version of the EV kit software. Save
the EV kit software to a temporary folder and decompress
the ZIP file.
The GUI drives I2C communication with the EV kit. Every
control in the GUI corresponds to a register setting within
the MAX77874. Refer to the register map within the device
data sheet for a complete description of the registers.
Figure 3. MAX77874 Evaluation Kit GUI Top-Level Interface
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