19-5925; Rev 0; 6/11
MAX16840 Evaluation Kit
Evaluates: MAX16840
General Description
Features
The MAX16840 evaluation kit (EV kit) demonstrates the
MAX16840 HBLED driver IC used for solid-state lighting
(SSL) applications. The EV kit is configured in a buckboost topology providing an output power of 5.5W for 3
to 5 LEDs. The IC is designed for standard multifacetedreflector (MR) applications. The EV kit’s typical input
power is 6.7W at 12V AC and features a power-factor
correction of 0.9 (typ).
S Input Voltage Ranges
9V AC to 13.2V AC from AC Source or Magnetic
Transformers
9V DC to 18V DC
Output of Several Electronic Transformers
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 some
electronic transformers and trailing-edge dimmer combination and some magnetic transformers and leadingedge dimmer combination.
S 5.5W Output Power
S Drives 3 to 5 Series HBLEDs
S 36V Overvoltage Protection
S Demonstrates IC Power-Factor Correction
S Proven PCB Layout
S Fully Assembled and Tested
Ordering Information appears at end of data sheet.
Component List
DESIGNATION
QTY
AC1, AC2,
LED+, LED-,
LED-B
0
C1, C8
DESCRIPTION
DESIGNATION
QTY
DESCRIPTION
Not installed, test points
C10
0
Not installed, ceramic capacitor
(1206)
2
0.33FF Q10%, 25V X7R
ceramic capacitors (0805)
Murata GRM21BR71E334K
C11
1
1000pF Q5%, 50V C0G
ceramic capacitor (0402)
Murata GRM1555C1H102J
C2, C9
2
10FF Q10%, 25V X7R ceramic
capacitors (1206)
Taiyo Yuden TMK316AB7106K
D1
1
3A, 60V Schottky diode (SMA)
Diodes Inc. B360A-13-F
C3
1
2.2FF Q10% 6.3V X7R ceramic
capacitor (0603)
AVX 06036C225KAT2A
D2
1
Schottky bridge rectifier diode
(HD DIP)
Central Semi CBRHDSH1-40L
C4
1
0.1FF Q10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H104K
D3
1
36V zener diode (SOD323)
Fairchild MM3Z36VC
(Top Mark: ZV)
C5
1
1500pF Q10%, 50V X7R
ceramic capacitor (0603)
Murata GRM188R71H152KA
D4
1
4.3V zener diode (SOD123)
Fairchild MMSZ5229B
(Top Mark: D4)
1
1.75A, 63V fuse
1
220pF Q5%, 50V C0G ceramic
capacitor (0603)
Murata GRM1555C1H221J
F1
C6
L1
1
27FH, 3.1A inductor
Würth 7447798271
C7
1
2.2FF Q10%, 16V X7R ceramic
capacitor (1206)
Murata GRM31MR71C225K
L2
1
3.3FH, 1A inductor
TDK MLP2520S3R3S
__________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX16840 Evaluation Kit
Evaluates: MAX16840
Component List (continued)
DESIGNATION
QTY
L3
1
Q1
1
Q2
1
DESCRIPTION
DESIGNATION
QTY
R5
1
10kI Q5% resistor (0603)
R6
1
22V, 400A varistor (1210)
R7
1
10kI Q1% resistor (0603)
R8
1
340kI Q1% resistor (0603)
R9, R10
2
12kI Q5% resistors (0402)
R11
1
1.5kI, 1/4W resistor (0805)
Panasonic-ECG ERJ-P06J152V
1
0.25I Q1%, 1/2W resistor
(1206)
TT Electronics/IRC
LRC-LR1206LF-01-R250
U1
1
LED driver with integrated
switch (10 TDFN-EP)
Maxim MAX16840ATB+
(Top Mark: AWY)
—
1
PCB: MAX16840 EVALUATION
KIT
22FH, 1.75A inductor
TDK VLC6045T-220M
60V, 20mA npn transistor
(SOT23)
Central Semi CMPT3904E
(Top Mark: C1AE)
30V, 50mA, dual npn transistor
(SOT363)
Central Semi CMKT5088
(Top Mark: K88)
R1
1
100I Q5% resistor (0603)
R2
1
1kI Q5% resistor (0603)
R3
1
0.22I Q1%, 1/3W resistor
(1206)
TT Electronics /IRC
LRC -LR1206LF-01-R220-F
R4
1
34.8kI Q1% resistor (0603)
R12
DESCRIPTION
Component Suppliers
SUPPLIER
PHONE
WEBSITE
AVX Corporation
843-946-0238
www.avx.com
Central Semiconductor Corp.
631-435-1110
www.centralsemi.com
Coilcraft, Inc.
847-639-6400
www.coilcraft.com
Diodes Incorporated
805-446-4800
www.diodes.com
Littelfuse, Inc.
773-628-1000
www.littelfuse.com
Murata Electronics North America, Inc.
770-436-1300
www.murata-northamerica.com
Panasonic Corp.
800-344-2112
www.panasonic.com
Taiyo Yuden
800-348-2496
www.t-yuden.com
TDK Corp.
847-803-6100
www.component.tdk.com
TT Electronics, PLC (IRC, Inc.)
40-0-1932-841310
www.ttelectronics.com
Note: Indicate you are using the MAX16840 when contacting these component suppliers.
Quick Start
Required Equipment
•
MAX16840 EV kit
•
AC or DC source
•
3 to 5 series-connected LED strings rated no less
than 500mA
•
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.
1) Connect the AC or DC source to the AC1 and AC2
test-point holes.
2) Connect the LED string anode and cathode to the
LED+ and LED- test-point holes, respectively.
3) Clip the current probe across the LED+ wire to
measure the LED current.
4) Enable the power supply.
5) Measure the LED current using the current probe.
__________________________________________________________________ Maxim Integrated Products 2
MAX16840 Evaluation Kit
Evaluates: MAX16840
Detailed Description of Hardware
The MAX16840 EV kit demonstrates the MAX16840
HBLED driver IC. The IC is an average current-modecontrol HBLED driver IC for step-down (buck), step-up
(boost), and step-down/step-up (buck-boost) topologies
in low-voltage SSL applications. The IC has an integrated 0.2I (max), 48V switching MOSFET that allows
the device to be used in lighting applications for MR16
and other SSL applications for power levels up to 10W.
The IC uses a proprietary input current-control scheme
to achieve power-factor correction. The IC’s LED driver
uses constant-frequency average current-mode control
to control the duty cycle of the integrated switching
MOSFET. The IC is available in a 10-pin TDFN package
with an exposed pad.
The EV kit circuit is configured in a buck-boost topology, which operates at the IC’s fixed 300kHz switching
frequency and provides up to 5.5W of output power for
a string of 3 to 5 series HBLEDs connected at the LED+
and LED- test-point holes. The EV kit circuit operates
from a 9V to 13.2V AC or DC supply voltage and from
electronic transformers. The EV kit is designed on a
proven 2oz copper, two-layer, small PCB-footprint design
that accommodates an MR16 application form factor.
The IC uses average current-mode control and the circuit is configured such that the average current flows in
current-sense resistor R3 on a cycle-by-cycle (switching
frequency) basis and is set by the voltage on the REFI
pin. The average current per switching cycle flowing into
R3 is:
I AV =
VREFI
6.075 × R3
where VREFI is the voltage at the IC’s REFI pin and R3 is
in ohms.
Circuit components C3, C7, Q2, R4, and R7–R10 are
used to average the rectified AC voltage and control the
input current. Components R7 and C7 form a lowpass
filter, with the average input voltage present across C7.
The averaged voltage is then used to control the current
in the current-mirror circuit formed by R8, R9, R10, and
Q2. The current flowing into R8 is approximately proportional to the voltage on C7 and is reflected on pin 3 of Q2
and sinks the same amount of current from pin 3 of Q2,
which flows into R8. The IC has a 50FA current source
available at the REFI pin. The current flowing into R4 sets
the input current or the average current flowing into R3.
The circuit attempts to maintain the input power over the
input voltage range of 9V AC to 13.2V AC almost constant, thus achieving LED current regulation in the range
of Q10% over the input range.
Inductor L2 is 3.3FH and has no effect for DC input voltages and low-frequency AC input voltages when the
MR16 is powered from a magnetic transformer. Figure
1 illustrates the input-current waveforms when the EV kit
is powered from a magnetic transformer with a 12V AC
60Hz output.
Inductor L2 has an effect when the unit is powered from
an electronic transformer (Figure 2).
Notice that the peak current drawn has increased with
the addition of the inductor (Figure 3). The first peak
drawn every 120Hz is ignored and consists of the input
current drawn by the IC circuit and the input capacitors.
Maximum LED+ Voltage
The IC features an internal 46V 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. However, when operating the EV
kit buck-boost circuit, the LED+ voltage should be limited
to 40V.
Electronic and Magnetic
Transformer Compatibility
The MR16 board was tested with 4 LEDs for electronic
and magnetic transformer compatibility and also with the
appropriate dimmers. See Table 1 for the results with the
different transformer models tested.
__________________________________________________________________ Maxim Integrated Products 3
MAX16840 Evaluation Kit
Evaluates: MAX16840
Table 1. Electronic Transformers Tested
RATED INPUT
VOLTAGE AND
POWER
MEASURED
(pF)
PERFORMANCE
(V)*
LED OUTPUT
VOLTAGE
(V)
Lightech
LVT60
120V, 60W
0.963
108 to 132
25.1
Lightech
LET60
120V, 60W
Lightech
LET75
120V, 75W
MANUFACTURER
(MODEL NAME)
LED OUTPUT
CURRENT
(mA)
LIGHTECH**
108 to 213
120 to 221
132 to 225
108 to 215
0.96
108 to 132
25.8
120 to 223
132 to 225
108 to 217
0.95
108 to 132
25.6
120 to 224
132 to 226
108 to 217
Lightech
LET105
120V, 105W
Lightech
LET151
120V, 150W
0.95
108 to 132
25.2
120 to 220
132 to 223
108 to 170
0.95
108 to 132
25
120 to 203
132 to 213
PONY**
108 to 214
Pony
PET-120-12-75
120V, 75W
Pony
PET-120-12-60
120V, 60W
0.95
108 to 132
25.2
120 to 223
132 to 225
108 to 215
0.95
108 to 132
25.3
120 to 220
132 to 224
BL TECHNOLOGY**
BL Technology
CV-10/75-12
108 to 219
120V, 75W
0.95
108 to 132
25.4
120 to 224
132 to 225
108 to 221
BL Technology
CV-10/60-12
120V, 60W
BL Technology
CV-10/150-12
120V, 150W
0.95
108 to 132
25.4
120 to 225
132 to 222
108 to 214
0.9
108 to 132
25.1
120 to 228
132 to 235
VARILIGHT**
207 to 218
Varilight
YT70L
230V,
0 to 70W
0.896
Varilight
YT150
230V,
0 to 150W
0.73
207 to 254
25.4
230 to 226
254 to 224
207 to 220
207 to 254
25.3
230 to 222
254 to 222
__________________________________________________________________ Maxim Integrated Products 4
MAX16840 Evaluation Kit
Evaluates: MAX16840
Table 1. Electronic Transformers Tested (continued)
RATED INPUT
VOLTAGE AND
POWER
MEASURED
(pF)
PERFORMANCE
(V)**
LED OUTPUT
VOLTAGE
(V)
Osram
HALOTRONIC
HTN 75/230-240
230V to 240V,
20W to 75W
0.88
207 to 254
25.4
Osram
HALOTRONIC
HTN 70/230-240
230V to 240V,
20W to 70W
0.942
Osram
HALOTRONIC
HTN 105/230-240
230V to 240V,
35W to 105W
0.91
Osram
ET-PARROT 105
220V to 240V,
35W to 105W
0.89
Osram
ET-P 60
220V to 240V,
20W to 60W
0.84
230V,
20W to 60W
0.866
220V,
20W to 50W
0.942
220V,
20W to 60W
0.932
220V
0.932
MANUFACTURER
(MODEL NAME)
LED OUTPUT
CURRENT
(mA)
OSRAM
207 to 208
230 to 217
254 to 224
207 to 200
207 to 254
25.3
230 to 213
254 to 222
207 to 203
207 to 254
25.1
230 to 215
254 to 224
207 to 199
207 to 254
25.2
230 to 213
254 to 221
207 to 201
207 to 254
25.3
230 to 214
254 to 222
NOBILE
Nobile
EN-60D
207 to 216
207 to 254
25.4
230 to 223
254 to 223
NVC
NVC
ET-60E
198 to 211
198 to 242
25.2
220 to 219
242 to 223
TCL
TCL
ET-60H
213 to 217
213 to 242
25.4
220 to 220
242 to 225
CDN
CDN
CS60
198 to 213
198 to 242
25.3
220 to 220
242 to 226
*No flicker from the designated voltage range.
**No flickering with Lutron SELVB-300PH-WH (ELV-300W) trailing-edge dimmers.
__________________________________________________________________ Maxim Integrated Products 5
MAX16840 Evaluation Kit
Evaluates: MAX16840
INPUT
CURRENT
500mA/div
INPUT
CURRENT
2A/div
10ms/div
2ms/div
Figure 1. Input Current Waveform Using a Magnetic
Transformer
Figure 2. Input Current Waveform Using an Electronic
Transformer with L2 Shorted
INPUT
CURRENT
2A/div
2ms/div
Figure 3. Input Current Waveform Using an Electronic
Transformer with L2 Installed
__________________________________________________________________ Maxim Integrated Products 6
MAX16840 Evaluation Kit
Evaluates: MAX16840
Figure 4. MAX16840 EV Kit Schematic
__________________________________________________________________ Maxim Integrated Products 7
MAX16840 Evaluation Kit
Evaluates: MAX16840
Figure 5. MAX16840 EV Kit Component Placement Guide—
Component Side
Figure 7. MAX16840 EV Kit PCB Layout—Solder Side
Figure 6. MAX16840 EV Kit PCB Layout—Component Side
Figure 8. MAX16840 EV Kit Component Placement Guide—
Solder Side
__________________________________________________________________ Maxim Integrated Products 8
MAX16840 Evaluation Kit
Evaluates: MAX16840
Ordering Information
PART
TYPE
MAX16840EVKIT#
EV Kit
#Denotes RoHS compliant.
__________________________________________________________________ Maxim Integrated Products 9
MAX16840 Evaluation Kit
Evaluates: MAX16840
Revision History
REVISION
NUMBER
REVISION
DATE
0
6/11
DESCRIPTION
Initial release
PAGES
CHANGED
—
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2011
Maxim Integrated Products
10
Maxim is a registered trademark of Maxim Integrated Products, Inc.