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.
Features
o6.5V to 40V Supply Voltage Range
oSelectable 150mA, 250mA, or 350mA Output
Current
o5V Regulated Output with 4mA Source Capability
oWide-Range Dimming Control with PWM
oLead(Pb)-Free and RoHS Compliant
oFully Assembled and Tested
Evaluates: MAX16835/MAX16836
MAX16836 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-4408; Rev 0; 1/09
Component List
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.
Ordering Information
Component Suppliers
DESIGNATION QTY DESCRIPTION
CS+, V5 2 Test points
C1, C2 2
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
JU1 1 2-pin header
JU2 1 3-pin header
R1 1 0.56Ω ±1%, 1/4W resistor (0805)
Susumu RP2012T-R56-F
DESIGNATION QTY DESCRIPTION
R2 1 0.82Ω ±1%, 1/4W resistor (0805)
Susumu RP2012T-R82-F
R3, R4 2 100kΩ ±5% resistors (0603)
U1 1
350mA adjustable high-brightness
LED driver (16 TQFN)
Maxim MAX16836ATE+
— 2 Shunts
— 1 PCB: MAX16836 Evaluation Kit+
SUPPLIER PHONE WEBSITE
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
Susumu International USA 208-328-0307 www.susumu-usa.com
TDK Corp. 847-803-6100 www.component.tdk.com
PART TYPE
MAX16836EVKIT+ EV Kit
+
Denotes lead(Pb)-free and RoHS compliant.
Note: Indicate that you are using the MAX16836 when contacting these component suppliers.
Evaluates: MAX16835/MAX16836
MAX16836 Evaluation Kit
2 _______________________________________________________________________________________
Quick Start
Recommended Equipment
Before beginning, the following equipment is needed:
• 0 to 30V or above, 0.5A power supply
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%.
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-
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:
where RSENSE is the external current-sense resistance
between CS+ and GND, ILED is the desired output cur-
rent, and VSENSE 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.
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.
RSENSE =V
I
SENSE
LED
SHUNT POSITION AND FUNCTION
JUMPER 1-2 (installed) 2-3 Open
JU1 U1 disabled — U1 enabled*
JU2 350mA* 250mA 150mA
Table 1. Jumper JU1 and JU2 Functions
*
Default position.
Evaluates: MAX16835/MAX16836
MAX16836 Evaluation Kit
_______________________________________________________________________________________ 3
Figure 1. MAX16836 EV Kit Schematic
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
___________________
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2009 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: MAX16835/MAX16836
Figure 2. MAX16836 EV Kit Component Placement Guide—
Components Side
MAX16836 Evaluation Kit
Figure 3. MAX16836 EV Kit PCB Layout—Component Side
Figure 4. MAX16836 EV Kit PCB Layout—Solder Side
