MAX16834EVKIT+ Maxim Integrated Products, MAX16834EVKIT+ Datasheet - Page 3

• Manufacturer Part Number: MAX16834EVKIT+
• Description: EVAL KIT FOR MAX16834
• Manufacturer: Maxim Integrated Products

Specifications of MAX16834EVKIT+

• Current - Output / Channel: 1A
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 28V
• Features: Dimmable
• Voltage - Input: 7 ~ 28V
• Utilized Ic / Part: MAX16834
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Before beginning, the following equipment is needed:
• 7V to 28V, 5A power supply
• Two digital voltmeters
• A series-connected LED string rated at 1A (28V max)
• A current probe to measure LED current
The MAX16834 EV kit is fully assembled and tested.
Follow the steps below to verify operation. Caution: Do
not turn on the power supply until all connections
are completed.
1) Verify that a shunt is installed at jumper JU1 (linear
2) Connect the power supply’s positive terminal to the
3) Connect the digital voltmeters across the VIN and
4) Connect the anode of the LED string to the LED+ pad.
5) Connect the cathode of the LED string to the LED-
6) Clip the current probe across the LED+ wire to mea-
7) Turn on the power supply and increase the input
8) Adjust potentiometer R17 clockwise for the desired
9) Measure the voltage between the LED+ and LED-
The MAX16834 EV kit demonstrates the MAX16834 cur-
rent mode HB LED driver IC. The MAX16834 EV kit is
configured as a step-up (boost) topology circuit with
peak inductor current and average current control for
external HB LEDs. The MAX16834 EV kit operates from
a DC supply voltage of 7V to 28V and requires up to
5A. The EV kit circuit is configured to deliver up to 1A of
current into a series LED string with a maximum forward
voltage of 28V.
Detailed Description of Hardware
dimming control).
VIN PCB pad on the EV kit. Connect the power sup-
ply’s ground terminal to the PGND PCB pad.
PGND PCB pads and the LED+ and LED- PCB pads.
pad.
sure the LED current.
voltage to 7V.
LED current.
PCB pads.
_______________________________________________________________________________________
Required Equipment
Quick Start
Procedure
MAX16834 Evaluation Kit
The EV kit sets the minimum peak inductor current-limit
threshold to 5A using resistor R9. The MAX16834 EV kit
can be configured for either an analog linear input volt-
age or digital PWM input signal to control the LED
brightness using jumper JU1. The average LED current
is set to a maximum of 1A by resistor R5 and can be
adjusted using potentiometer R17. A PWMDIM PCB
pad is provided for PWM dimming operation of the
external LEDs.
The EV kit switching frequency is set to 600kHz using
resistor R15 and can also be synchronized to an exter-
nal clock source by applying a digital signal at the
RT/SYNC PCB pad. Refer to the Internal Oscillator sec-
tion in the MAX16834 IC data sheet for information on
setting other switching frequencies. This EV kit features
a UVLO set to 6.4V using resistors R1 and R2. The EV
kit also features an active-low FLT PCB pad to monitor
for open or short-circuit LED fault conditions at the
LED+ and LED- PCB pads, or an overtemperature IC
fault condition.
The MAX16834 EV kit can also be configured for buck-
boost operation by changing various components. See
the Reconfiguring the MAX16834 EV Kit for Buck-Boost
Operation section for additional information.
The MAX16834 EV kit’s undervoltage lockout threshold
is configured to 6.4V using resistors R1 and R2. The
UVEN PCB pad can be used to disable the EV kit circuit
by connecting UVEN to SGND. To configure the circuit
to a different UVLO threshold, refer to the Setting the
UVLO Threshold section in the MAX16834 IC data sheet.
Current-sense resistor R9 sets the EV kit’s minimum
peak inductor current limit to 5A. Use the following
equation to calculate a new R9 value when reconfigur-
ing the inductor peak current limit:
where 250mV is the MAX16834 minimum peak current-
sense threshold, I
amps, and R9 is the sense resistor in milliohms.
Refer to the Peak Current-Sense Resistor (R8) section
in the MAX16834 IC data sheet for additional informa-
tion on setting the peak current-limit threshold.
Peak Inductor Current-Limit Setting
Undervoltage Lockout (UVLO)
R
PEAK
9
=
(
I
PEAK
is the inductor peak current in
250
×
mV
1 25
.
)
A
3