19-4408; Rev 0; 1/09
MAX16836 Evaluation Kit
General Description
The MAX16836 evaluation kit (EV kit) demonstrates a
current-controlled, high-output-current LED driver
based on the MAX16836 current regulator. The EV kit is
capable of supplying regulated output currents of up to
350mA and runs at supply voltages between 6.5V to
40V.
The MAX16836 EV kit features a PWM dimming control,
user-selectable three-level output-current setting, and a
5V regulated output, which supplies up to 4mA of out-
put current. The MAX16836 EV kit also evaluates the
MAX16835 IC; contact the factory for a free sample of
the MAX16835 IC.
o
6.5V to 40V Supply Voltage Range
o
Selectable 150mA, 250mA, or 350mA Output
Current
o
5V Regulated Output with 4mA Source Capability
o
Wide-Range Dimming Control with PWM
o
Lead(Pb)-Free and RoHS Compliant
o
Fully Assembled and Tested
Features
Evaluates: MAX16835/MAX16836
Ordering Information
PART
MAX16836EVKIT+
TYPE
EV Kit
+Denotes
lead(Pb)-free and RoHS compliant.
Component List
DESIGNATION
CS+, V5
QTY
2
DESCRIPTION
Test points
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
2-pin header
3-pin header
0.56Ω ±1%, 1/4W resistor (0805)
Susumu RP2012T-R56-F
—
—
2
1
DESIGNATION
R2
R3, R4
U1
QTY
1
2
1
DESCRIPTION
0.82Ω ±1%, 1/4W resistor (0805)
Susumu RP2012T-R82-F
100kΩ ±5% resistors (0603)
350mA adjustable high-brightness
LED driver (16 TQFN)
Maxim MAX16836ATE+
Shunts
PCB: MAX16836 Evaluation Kit+
C1, C2
2
JU1
JU2
R1
1
1
1
Component Suppliers
SUPPLIER
Murata Electronics North America, Inc.
Susumu International USA
TDK Corp.
PHONE
770-436-1300
208-328-0307
847-803-6100
WEBSITE
www.murata-northamerica.com
www.susumu-usa.com
www.component.tdk.com
Note:
Indicate that you are using the MAX16836 when contacting these component suppliers.
________________________________________________________________
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.
MAX16836 Evaluation Kit
Evaluates: MAX16835/MAX16836
Quick Start
Recommended Equipment
Before beginning, the following equipment is needed:
• 0 to 30V or above, 0.5A power supply
els of output LED currents by setting jumper JU2 (see
Table 1 for jumper settings). The MAX16836 EV kit also
includes a connection for the 5V regulated output and
access to the on-board current-sense resistor.
Output Current Setting
The output current can be adjusted by replacing resis-
tors R2 or R3 with values calculated using the following
equation:
R
SENSE
=
V
SENSE
I
LED
Procedure
The MAX16836 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 a DC power supply (0 to 30V or above,
0.5A) to VIN.
2) Verify that a shunt is not installed across jumper
JU1 to enable U1.
3) Verify that a shunt is installed across pins 1-2 of
jumper JU2 to select 350mA output current.
4) Connect a 350mA-rated LED between LED+ and
LED-.
5) Turn on the power supply and increase the input
voltage to above 6.5V. The LED should glow with
full brightness. Measure the LED current, which
should be 350mA
±3.5%.
6) Increase the supply voltage and measure the LED
current, which should be 350mA
±3.5%.
Note that
the maximum voltage drop between IN and OUT
should be ~7V to limit the maximum power dissipa-
tion to approximately 2.5W.
7) Measure the voltage across V5, which should be
5V
±4%.
where R
SENSE
is the external current-sense resistance
between CS+ and GND, I
LED
is the desired output cur-
rent, and V
SENSE
is 200mV (typ).
PWM Dimming
The PWM dimming controls the LED brightness by
adjusting the duty cycle of the PWM input signal con-
nected to the DIM input. A high at the DIM input turns
on the output current and a low turns off the output cur-
rent. Connect a signal with peak amplitude between 5V
and 40V, frequency between 100Hz and 2kHz, and
vary the duty cycle to adjust the LED brightness. LED
brightness increases when duty cycle increases and
vice versa. Duty cycle can be as low as 10% even at a
PWM frequency of 2kHz.
5V Regulated Output
The 5V regulator can be used to power other compo-
nents from the V5 test point. The 5V output supplies up
to 4mA of current.
Detailed Description of Hardware
The MAX16836 EV kit demonstrates a high-output-
current LED driver with accurate current control based
on the MAX16836 current regulator. The MAX16836 EV
kit is capable of supplying regulated output currents of
up to 350mA and runs at supply voltages between
6.5V to 40V. If the supply voltage is above the LED
operating voltage by more than 7V, the maximum out-
put current should be limited to prevent the device
from entering into thermal shutdown due to excessive
power dissipation.
The MAX16836 EV kit features PWM dimming to control
the LED brightness by varying the duty cycle of the
PWM input signal. Users can select between three lev-
Jumper Selection
Two-pin jumper JU1 controls the EN pin of the
MAX16836 and enables or disables the device. Three-
pin jumper JU2 selects between three different output
current settings. Table 1 lists the jumper options.
Table 1. Jumper JU1 and JU2 Functions
JUMPER
JU1
JU2
SHUNT POSITION AND FUNCTION
1-2 (installed)
U1 disabled
350mA*
2-3
—
250mA
Open
U1 enabled*
150mA
*Default
position.
2
_______________________________________________________________________________________
MAX16836 Evaluation Kit
Evaluates: MAX16835/MAX16836
Figure 2. MAX16836 EV Kit Component Placement Guide—
Components Side
Figure 3. MAX16836 EV Kit PCB Layout—Component Side
Figure 4. MAX16836 EV Kit PCB Layout—Solder Side
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.
4
___________________
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© 2009 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.
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