MAX31840 Evaluation Kit
Evaluates: MAX31840
General Description
The MAX31840 evaluation kit (EV kit) demonstrates the
MAX31840 LED driver IC used for dimmable 12V MR16
as well as AR111 and other 12V lighting applications. The
EV kit is configured in a boost topology that provides an
output power of up to 13W for up to 35V LED forward
voltage. The IC is designed for the boost architecture to
address 35W and 50W MR16 LED replacement bulbs.
The EV kit’s typical efficiency 90% at 12V AC and features
a power-factor correction of 0.9 (typ).
The EV kit is a fully assembled and tested surface-mount
PCB designed and optimized to accommodate an MR16
application form factor. The EV kit is dimmable with most
electronic transformers and trailing-edge dimmer combi-
nations. The EV kit includes bleeder and constant power
circuits for enhanced electronic transformer performance.
Quick Start
Required Equipment
●
MAX31840 EV kit
● 12V AC or DC supply, or a 12V electronic transformer
●
Trailing edge dimmer
●
Current probe to measure the LED current
Procedure
The EV kit is fully assembled and tested. Follow the steps
below to verify board operation.
Caution:
Do not turn on
the power supply until all connections are completed.
Test with AC or DC Source
1)
2)
3)
1)
2)
3)
4)
5)
6)
Connect the AC or DC source to the AC1 and AC2
test-point pads.
Enable the power supply.
Measure the LED current using the current probe.
Connect the output of a trailing edge dimmer to the
input of electronic transformer.
Connect the output of the electronic transformer to
the AC1 and AC2 test-point pads.
Connect the input of the dimmer to power outlet.
Turn on the dimmer.
Measure the LED current using the current probe.
Adjust dimmer setting to change brightness on the
LED.
Features
●
Input Voltage Ranges
•
9V AC to 13.2V AC from AC Source
• 6.5V to 13.8V DC or Output of Electronic
Transformers
●
Drives Up to 35V LED Forward Voltage
●
36V Overvoltage Protection
●
Up to 13W Output Power
●
Demonstrates IC Power-Factor Correction
● Proven PCB Layout
● Fully Assembled and Tested
Ordering Information
appears at end of data sheet.
Test with Electronic Transformer Plus Dimmer
319-100049; Rev 0; 8/17
MAX31840 Evaluation Kit
Evaluates: MAX31840
Detailed Description of Hardware
The MAX31840 EV kit demonstrates the MAX31840
MR16 LED driver. The MAX31840 is an average current-
mode control LED driver IC for boost topology in low-
voltage SSL applications. The MAX31840 incorporates
a proprietary circuit that enables deep dimming and an
integrated bleeder to improve compatibility with a broad
range of electronic transformers.
The EV kit circuit is configured in boost topology that
operates at the IC’s fixed 700kHz switching frequency
and provides up to 13W of output power for HBLEDs
connected at the LED+ and LED- test-point holes. The EV
kit circuit operates from a 6.5V to 13.8V AC or 9V to 13.2V
DC supply or from electronic transformers. The EV kit is
designed on a proven 2oz copper, two layer, small PCB
footprint design that fits in a MR16 application form factor.
The IC regulates the average voltage on CS to 200mV.
The average input current is set by the current-sense
resistor R4. The average current is:
I
AV
=
0.2
R
4
With 0.2Ω R2 and 0.5Ω
R5, the power consumption of
the system is approximately 1000mA x 12V
IN
= 12W
(average current times input RMS voltage). This is equivalent
to 50W halogen bulb. For 35W equivalent application, use
0.33Ω for R4 and 0.82Ω
for R2.
R3 and C5 are lowpass filters to eliminate the high-
frequency components and glitches on the output signal
of the electronic transformer.
The electronic transformer constantly outputs short pulses
and checks the existence of any connected devices. If the
load is too small, the electronic transformer does not turn on.
The D1 diode provides a direct path for the electronic
transformer to turn on the internal LDO of the MAX31840.
The bleeder FET can be turned on only after LDO is enabled.
Maximum LED+ Voltage
The IC features an internal 36V overvoltage protection at
the IN pin to protect the internal switching MOSFET from
damage if the LED string is open or if the voltage on the
LED string is too high.
Electronic Transformer Compatibility
where 0.2 is the voltage at the IC’s CS pin and R4 is
in ohms. The R4 on the EV kit is 0.2Ω and the average
current is about 1000mA.
The CS pin monitors the current through the sense resistor
R4. When V
CS
falls below 180mV, the bleeder FET is
turned on to maintain the minimum load requirement and
keep the electronic transformer on. Current through the
bleeder FET is set by R2:
I
BLEEDER
=
0.5
R
2
The MR16 board was tested with 8 LEDs for electronic
transformer compatibility and also with the appropriate
dimmers. See
Table 1
for the results with the different
transformer models tested.
where 0.5 is the voltage at the BSRC pin and R2 is in
ohms. The R2 on the EV kit is 0.5Ω,
and I
BLEEDER
is
about 1000mA. R5 and R7 are used to provide protection
to the bleeder FET against high voltage at the output of
the rectifier.
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MAX31840 Evaluation Kit
Evaluates: MAX31840
Table 1. Electronic Transformers Tested
MANUFACTURER
(MODEL NAME)
KEYSTONE
KTET-75-1-SCP-DIM-HV-AL
PHILIPS
ET-E 60 220-240
ET-S 60 220-240
LUXMAN
ETH 60.202
HATCH
RS12-60M
BL TECHNOLOGIES
CV-10/75-12
LIGHTECH
LET 75
LET 60
LET 75 BF
RJ US
HD75-120
KS ELECTRONIC TRANSFORMER
—
110V, 50W
29.7
234
120V,75W
29.6
235
120V, 75W
120V, 60W
120V, 75W
29.1
29.1
29.3
234
221
221
120V, 75W
29
286
120V, 60W
28.7
276
220V to 240V
20W to 60W
32.5
182
220V to 240V
20W to 60W
220V to 240V
20W to 60W
31.7
31.5
226
211
120V, 75W
29.3
255
RATED INPUT VOLTAGE
AND POWER
LED OUTPUT
VOLTAGE (V)
LED OUTPUT
CURRENT (mA)
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MAX31840 Evaluation Kit
Evaluates: MAX31840
Component Suppliers
SUPPLIER
BOURNS
DIODES INCORPORATED
INTERNATIONAL RECTIFIER
MICRO COMMERCIAL COMPONENTS
MURATA
NICHICON
PANASONIC
ROHM SEMICONDUCTOR
STACKPOLE ELECTRONICS INC
TDK
TOSHIBA
YOGEO
www.bourns.com
www.diodes.com
www.infineon.com
www.mccsemi.com
www.murata.com
www.nichicon.co.jp
na.industrial.panasonic.com
www.rohm.com
www.seielect.com
www.component.tdk.com
toshiba.semicon-storage.com
www.yageo.com
WEBSITE
Note:
Indicate that you are using the MAX31840 when contacting these component suppliers.
Ordering Information
PART
MAX31840EVKIT#
#Denotes RoHS compliant.
TYPE
EV Kit
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MAX31840 Evaluation Kit
Evaluates: MAX31840
MAX31840 EV Kit Bill of Materials
ITEM
1
2
REF_DES
AC1, AC2
C1
DNI/DNP
—
—
QTY
2
1
N/A
GRM155R71E472KA01
CGA2B3X7R1H104K;
C1005X7R1H104K050BB;
GRM155R71H104KE14
UMK107BJ105KA-T;
C1608X5R1H105K080AB;
CL10A105KB8NNN;
GRM188R61H105KAAL
UPW1H151MPD1TD
MFG PART #
MANUFACTURER
N/A
MURATA
VALUE
TP_SMD_3MM
4700PF
DESCRIPTION
TEST POINT; PAD DIA 3MM; SMD
CAPACITOR; SMT (0402); CERAMIC CHIP;
4700PF; 25V; TOL = 10%;
TG = -55°C TO +125°C; TC = X7R;
CAPACITOR; SMT (0402); CERAMIC CHIP;
0.1µF; 50V; TOL = 10%;
TG = -55°C TO +125°C; TC = X7R
CAPACITOR; SMT (0603); CERAMIC CHIP;
1µF; 50V; TOL = 10%; MODEL = _MK SERIES;
TG = -55°C TO +85°C
CAPACITOR; THROUGH HOLE-RADIAL LEAD;
ALUMINUM-ELECTROLYTIC; 150µF; 50V; TOL = 20%
CAPACITOR; SMT (0402); CERAMIC;
0.22µF; 16V; TOL = 10%; MODEL = GRM SERIES;
TG = -55°C TO +125°C; TC = X7R
DIODE; SCH; SMT (SOD-923); PIV = 45V; IF = 0.1A
DIODE; SCH; SMA; PIV = 60V; IF = 3A
INDUCTOR; SMT; WOUND FERRITE;
100µH; TOL =
±20%;
0.9A;
TRAN; N-CHANNEL MOSFET; NCH;
SOT-23; PD-(0.8W); I-(4.2A); V-(20V)
RESISTOR; 0603; 100Ω; 1%; 100PPM;
0.125W; THIN FILM
RESISTOR; 1206; 0.5Ω; 1%; 100PPM;
0.5W; THICK FILM
RESISTOR, 0402, 560Ω, 1%, 100PPM,
0.0625W, THICK FILM
RESISTOR; 0805; 0.2Ω; 1%; 600PPM;
0.25W; THICK FILM
RESISTOR; 1210; 3.9Ω; 5%;
-400+150PPM; 0.5W; THICK FILM
EVKIT PART-IC; TDFN8-EP; MR16 LED DRIVER
WITH INTEGRATED CONTROL MOSFET AND
DEEP DIMMING; PACKAGE CODE: T833+3;
PACKAGE OUTLINE: 21-0137P
DIODE; SCH; TO-269AA; PIV = 60V; IF = 1A
PCB:MAX31840
TEST POINT; PIN DIA = 0.1IN; TOTAL LENGTH = 0.3IN;
BOARD HOLE = 0.04IN; YELLOW; PHOSPHOR BRONZE
WIRE SILVER PLATE FINISH;
3
C2
—
1
TDK; MURATA
0.1µF
4
C3
—
1
TAIYO YUDEN; TDK;
SAMSUNG; MURATA
1µF
5
C4
—
1
NICHICON
150µF
6
7
8
9
10
11
12
13
14
15
C5
D1
D2
L1
Q1
R1
R2
R3
R4
R5, R7
—
—
—
—
—
—
—
—
—
—
1
1
1
1
1
1
1
1
1
2
GRM155R71C224KA12
1SS417
B360A-13-F
VLS6045EX-101M
IRLML2502PBF
RNCP0603FTD100R
CSR1206FTR500
ERJ-2RKF5600X
RL0805FR-7W0R2L
ERJ14YJ3R9
MURATA
TOSHIBA
DIODES INCORPORATED
TDK
INTERNATIONAL RECTIFIER
STACKPOLE ELECTRONICS INC
STACKPOLE ELECTRONICS INC.
PANASONIC
YAGEO
PANASONIC
0.22µF
1SS417
B360A-13-F
100UH
IRLML2502PBF
100
0.5
560
0.2
3.9
16
17
18
19
TOTAL
U1
U2
PCB
LED+, LED-
—
—
—
DNP
1
1
1
0
20
MAX31840
MB16S
MAX31840
5004
MAXIM
MICRO COMMERCIAL COMPONENTS
MAXIM
KEYSTONE
MAX31840
MB16S
PCB
N/A
NOTE: DNI--> DO NOT INSTALL(PACKOUT) ; DNP--> DO NOT PROCURE
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