MAX16807EVKIT+ Maxim Integrated Products, MAX16807EVKIT+ Datasheet - Page 3

• Manufacturer Part Number: MAX16807EVKIT+
• Description: EVAL KIT FOR MAX16807
• Manufacturer: Maxim Integrated Products

Specifications of MAX16807EVKIT+

• Current - Output / Channel: 50mA
• Outputs And Type: 8, Non-Isolated
• Voltage - Output: 32V
• Features: Dimmable
• Voltage - Input: 9 ~ 16V
• Utilized Ic / Part: MAX16807
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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The MAX16807 EV kit is a fully assembled and tested sur-
face-mount printed circuit board (PCB). Follow the steps
below to verify board operation. Caution: Do not enable
the power supply until all connections are made.
1) Adjust the 16V power supply output to 12V.
2) Connect the 5V power supply between the EV kit’s
3) Connect the SHDN pad to the VIN pad.
4) Enable both power supplies.
5) Use the voltmeter to verify that the voltage at head-
6) Disable the VIN power-supply output.
7) Connect the anode of each LED string to VLED (pins
8) Enable the VIN power-supply output.
9) Verify that all LEDs are illuminating.
10) Connect a PWM signal with amplitude of 5V and a fre-
This EV kit evaluates the MAX16807 IC, which has two
major sections. The first section consists of eight con-
stant-current LED drivers for LED strings. Each driver
can sink up to 55mA through an LED string when ON
One 16V, 2A adjustable power supply
One 5V power supply
One voltmeter
Eight LED strings with a total forward voltage rating
≤ 32V (optional)
One PWM signal generator (optional)
Connect this power supply between the EV kit’s VIN
and GND pads.
VBIAS and GND pads.
er J1, pins J1-1 and J1-2, referencing GND, mea-
sures approximately 36V.
J1-1and J1-2). Connect the cathode of each LED
string to channels OUT0–OUT7 (pins J1-3–J1-10).
quency between 100Hz and 2kHz to the PWM input
PC pad. The LED brightness should increase as the
PWM signal’s duty cycle increases and vice versa.
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Recommended Equipment
Detailed Description
Quick Start
Procedure
MAX16807 Evaluation Kit
and block up to 36V when OFF. The second section is
a high-performance, current-mode PWM controller that
controls a power converter to generate a voltage for dri-
ving the LED strings. The EV kit uses the PWM con-
troller to drive a boost-converter circuit, which takes a
9V to 16V input and generates up to 36V LED voltage at
header pins J1-1 and J1-2 (VLED). To drive the LED
string with constant current, connect the LED string
between the VLED output and any of the eight con-
stant-current sink outputs. The sink current of each out-
put is configured to 50mA with resistor R7.
The LED voltage generated by the boost converter on
the MAX16807 EV kit is adaptive. The LED string with
the highest total forward voltage dominates the control
loop. The boost-converter voltage is adjusted so that
the driver associated with that string receives just
enough voltage as needed for current drive. All other
strings with lower total forward voltages will have
excess supply voltage, which is then dropped in the
associated driver. This feedback mechanism ensures
that the linear current-control circuit dissipates the mini-
mum possible power.
The MAX16807 EV kit does not require an external
microcontroller to enable the eight LED drivers. The EV
kit circuit is configured to enable all LED drivers by
tying the MAX16807 DIN (data-in) and LE (latch-
enable) pins to a logic-high signal and automatically
supplies approximately a 50kHz clock signal. Inverter
U2 is configured to generate the clock signal and to
implement the PWM dimming function. A 5V (VBIAS)
supply is also required to power the MAX16807 con-
stant-current output drivers and the inverter.
The MAX16807 EV kit requires an 8.8V to 16V power
supply connected across VIN and GND PC pads, and
a 5V power supply connected across VBIAS and GND
PC pads for normal operation. The 8.8V to 16V power
supply is used to provide power to the MAX16807 IC
(U1) and to the DC-DC step-up power converter. The
5V power supply is used to provide power to the con-
stant-current LED driver of the MAX16807 and to the
dual Schmitt trigger inverter (U2). The VBIAS power
supply also provides a logic-high voltage signal to the
DIN and LE pins.
Power Supplies
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