The MAX77231 evaluation kit (EV kit) is a fully assembled
and tested PCB for evaluating the MAX77231 low-noise
step-up DC-DC converter. It is optimized for boost
applications requiring very low ripple/noise and small PCB
space. The EV kit is set up to provide an 11.2V output
from an input voltage ranging from 2.7V to 4.8V, and can
deliver up to 10mA of current. The output ripple and noise
are suppressed to 35µV
RMS
. Other output voltages up to
16.2V can be factory set. Jumpers are provided to help
evaluate features of the MAX77231 IC.
Quick Start
Recommended Equipment
●
MAX77231 EV kit
●
2.5V to 6V 100mA bench power supply (PS1)
●
Two digital multimeters (DMM1, DMM2)
●
0–50mA electronic load or appropriate load resistors
Procedure
Features
The EV kit is a fully assembled and tested surface mount
circuit board. Follow the steps below to set up and verify
the IC and board operation:
1)
2)
Verify that the jumpers on the EV kit are configured
as shown in
Table 1.
If using an electronic load, set it to 6mA and turn it
off. Alternately, obtain a 2kΩ resistor (values from
1.8kΩ to 2.4kΩ are also acceptable).
Set the power supply to 3.6V and turn it off.
Connect the MAX77231 evaluation board, bench
power supply and DMMs as shown in
Figure 1.
Turn on the power supply.
Verify that voltage read by DMM1 is 3.6V.
Verify that voltage read by DMM2 is 11.2V.
Sweep the power supply down to 2.7V.
Verify that voltage read by DMM2 is 11.2V.
●
Ultra-Small Solution Circuit Area (< 7mm
2
)
●
35µV
RMS
Typical Output Ripple/Noise
●
2.7V to 4.8V Input Range
●
11.2V/10mA Output
●
Output Factory-Trimmable from 11.2V to 16.2V
●
125µA No-Load Supply Current—Output On
●
< 1µA Shutdown Supply Current
●
True Shutdown Load Disconnect
●
Selectable Active Discharge
●
Proven PCB layout
●
Fully Assembled and Tested
Ordering Information
appears at end of data sheet.
3)
4)
5)
6)
7)
8)
9)
10) Sweep the power supply up to 4.8V.
11) Verify that voltage read by DMM2 is 11.2V.
12) Disconnect RL (or electronic load).
13) Verify that voltage read by DMM2 is 11.2V.
Table 1. Default Jumper Settings
JUMPER
JU1
JU2
DEFAULT SHUNT
POSITION
1-2
1-2
MODE
Active Discharge Off
Power On
19-7638; Rev 0; 1/16
MAX77231 Evaluation Kit
Evaluates: MAX77231
DMM2
DMM1
PS1
3.6V
+
-
+
-
+
-
RL = 2kΩ
TEST LOAD
(OR 6mA
ELECTRONIC
LOAD)
MAX77231 EV KIT
Figure 1. Quick-Start Connection Diagram
Detailed Description
The MAX77231 EV kit evaluates the MAX77231 low-
noise boost DC-DC converter IC. The IC utilizes a high-
frequency PFM boost followed by a low-noise pMOS
linear LDO regulator that reduces output noise and ripple
to 35µV
RMS
in a 1MHz BW at V
OUT
.
The step-up converter output is 11.7V at V
BST
, and 11.2V
at V
OUT
from an input voltage range from 2.7V to 4.8V.
Other output voltages up to 16.2V are available after
replacing U1. Contact the factory for other ICs.
Enable/Active Discharge
The MAX77231 can be disabled with/without active
discharge. See
Table 2
for ENM and ENS control logic for
active discharge.
Table 2. MAX77231 Enable Truth Table
JU1
JUMPER POSITION
2-3
1-2
1-2
ENM
0
1
1
X
2-3
1-2
JU2
JUMPER POSITION
ENS
X
0
1
POWER STATE
Power Down
Power Down
Active
ACTIVE
DISCHARGE
ON
OFF
OFF
VIN
ENM
ENS
VBST
VOUT
GND
Overload and Short Circuit Protection
The MAX77231 is fully protected against output short circuits.
In the case of a short circuit, off time is lengthened to prevent
inductor current from climbing. The device will source
current into the short indefinitely, without damage, until
the short is removed.
Note, however, that only OUT (and not BST) is overload
protected. A short at V
BST
to ground may cause inductor
and LX current to rise above guaranteed operating levels.
www.maximintegrated.com
Maxim Integrated
│
2
MAX77231 Evaluation Kit
Evaluates: MAX77231
Component Suppliers
SUPPLIER
Taiyo Yuden
Cyntec
WEBSITE
www.t-yuden.com
www.cyntec.com
Ordering Information
PART
MAX77231EVKIT#
#Denotes
RoHS compliant.
TYPE
EV Kit
Note:
Indicate that you are ordering the MAX77231 EV kit
when contacting these suppliers.
Component List, PCB Layout, and
Schematic
●
MAX77231 EV BOM
●
MAX77231 EV PCB Layout
●
MAX77231 EV Schematic
See the following links for component information, PCB layout
diagrams, and schematics.
●
MAX77231 EV Minimal Component Schematic
www.maximintegrated.com
Maxim Integrated
│
3
MAX77231 Evaluation Kit
Evaluates: MAX77231
Revision History
REVISION
NUMBER
0
REVISION
DATE
1/16
Initial release
DESCRIPTION
PAGES
CHANGED
—
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
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