MAX16818_15 Datasheet, PDF (24/25 Pages) Maxim Integrated Products – 1.5MHz, 30A High-Efficiency, LED Driver with Rapid LED Current Pulsing

MAX16818
1.5MHz, 30A High-Efficiency, LED Driver
with Rapid LED Current Pulsing
PCB Layout Guidelines
Use the following guidelines to layout the switching
voltage regulator:
1) Place the IN, V_CC, and V_DD bypass capacitors close
to the MAX16818.
2) Minimize the area and length of the high current loops
from the input capacitor, upper switching MOSFET,
inductor, and output capacitor back to the input
capacitor negative terminal.
3) Keep short the current loop formed by the lower
switching MOSFET, inductor, and output capacitor.
4) Place the Schottky diodes close to the lower MOSFETs
and on the same side of the PCB.
5) Keep the SGND and PGND isolated and connect
them at one single point.
6) Run the current-sense lines CSP and CSN very close
to each other to minimize the loop area. Similarly, run
the remote voltage-sense lines SENSE+ and SENSE-
close to each other. Do not cross these critical signal
lines through power circuitry. Sense the current right
at the pads of the current-sense resistors.
7) Avoid long traces between the V_DD bypass
capacitors, the driver output of the MAX16818, the
MOSFET gates, and PGND. Minimize the loop formed
by the V_CC bypass capacitors, bootstrap diode,
bootstrap capacitor, the MAX16818, and the upper
MOSFET gate.
8) Distribute the power components evenly across the
board for proper heat dissipation.
9) Provide enough copper area at and around the
switching MOSFETs, inductor, and sense resistors to
aid in thermal dissipation.
10) Use wide copper traces (2oz) to keep trace
inductance and resistance low to maximize efficiency.
Wide traces also cool heat-generating components.
Pin Configuration
TOP VIEW
21 20 19 18 17 16 15
SGND 22
SENSE- 23
SENSE+ 24
SGND ²⁵
IN 26
MAX16818
V_CC 27
V_DD 28
* EXPOSED PAD
+
12 34 5 67
14 LIM
13 V_IOUT
12 RT/SYNC
11 EN
10 PGOOD
9 CLKOUT
8 SGND
TQFN
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
28 TQFN-EP
PACKAGE
CODE
T2855+3
OUTLINE
NO.
21-0140
LAND
PATTERN NO.
90-0023
www.maximintegrated.com
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