MAX16820EVKIT+ Maxim Integrated Products, MAX16820EVKIT+ Datasheet - Page 8

• Manufacturer Part Number: MAX16820EVKIT+
• Description: EVAL KIT FOR MAX16820
• Manufacturer: Maxim Integrated Products

Specifications of MAX16820EVKIT+

• Current - Output / Channel: 1A
• Outputs And Type: 1, Non-Isolated
• Voltage - Output: 20V
• Features: Dimmable
• Voltage - Input: 5 ~ 28V
• Utilized Ic / Part: MAX16820
• Core Chip: MAX16820
• No. Of Outputs: 1
• Output Current: 1A
• Dimming Control Type: PWM
• Development Tool Type: Hardware - Eval/Demo Board
• Peak Reflow Compatible (260 C): Yes
• Rohs Compliant: Yes
• Leaded Process Compatible: Yes
• Mcu Supported Families: MAX16820
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX16819/MAX16820’s gate driver is capable of
sourcing 0.5A and sinking 1A of current. MOSFET selec-
tion is based on the maximum input operating voltage
V
quency. Choose a MOSFET that has a higher break-
down voltage than the maximum operation voltage, low
R
MOSFET threshold voltage must be adequate if operat-
ed at the low end of the input-voltage operating range.
The forward voltage of the freewheeling diode should
be as low as possible for better efficiency. A Schottky
diode is a good choice as long as the breakdown volt-
age is high enough to withstand the maximum operat-
ing voltage.
The forward current rating of the diode must be at least
equal to the maximum LED current.
The LED current ripple is equal to the inductor current
ripple. In cases when a lower LED current ripple is
needed, a capacitor can be placed across the LED ter-
minals.
2MHz High-Brightness LED Drivers with
High-Side Current Sense and 5000:1 Dimming
8
IN
DS(ON)
, output current I
_______________________________________________________________________________________
, and low total charge for better efficiency.
Freewheeling Diode Selection
LED
, and operating switching fre-
LED Current Ripple
MOSFET Selection
Careful PCB layout is critical to achieve low switching
losses and stable operation. Use a multilayer board
whenever possible for better noise immunity. Minimize
ground noise by connecting high-current ground
returns, the input bypass-capacitor ground lead, and
the output-filter ground lead to a single point (star
ground configuration). In normal operation, there are
two power loops. One is formed when the MOSFET is
on and the high current flows through IN—R
LEDs—Inductor—MOSFET—GND. The other loop is
formed when the MOSFET is off when the high current
circulates through R
wheeling diode. To minimize noise interaction, each
loop area should be as small as possible.
Place R
and IN. For better noise immunity, a Kelvin connection
is strongly recommended between CSN and R
Connect the exposed paddle to a large-area ground
plane for improved power dissipation.
PROCESS: BiCMOS
SENSE
as close as possible to the input filter
SENSE
PCB Layout Guidelines
Chip Information
—LEDs—Inductor—free-
SENSE
SENSE
—
.