MAX16838AUP/V+T Maxim Integrated Products, MAX16838AUP/V+T Datasheet - Page 17

• Manufacturer Part Number: MAX16838AUP/V+T
• Description: LED Drivers Integrated 2-Channel High-Brightness LED
• Manufacturer: Maxim Integrated Products

Specifications of MAX16838AUP/V+T

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Integrated, 2-Channel, High-Brightness LED Driver
Figure
Figure 4 shows a SEPIC application circuit using the
MAX16838. The SEPIC topology is necessary to keep
the output voltage of the DC-DC converter regulated
when the input voltage can rise above and drop below
the output voltage.
Figure 5 shows a boost-buck configuration with the
MAX16838 and the MAX15054.
LED driver circuits based on the MAX16838 device use
a high-frequency switching converter to generate the
voltage for LED strings. Take proper care while laying
out the circuit to ensure proper operation. The switching-
converter part of the circuit has nodes with very fast volt-
age changes that could lead to undesirable effects on
the sensitive parts of the circuit. Follow these guidelines
to reduce noise as much as possible:
4. SEPIC Configuration
with High-Voltage Boost and SEPIC Controller
______________________________________________________________________________________
R2
R1
EN
EN
PCB Layout Considerations
Boost-Buck Configuration
C
COMP
C
VCC
C
SEPIC Operation
R
R
DRV
COMP
DRV
C
4.75V TO 40V
IN
EN
CFB
V
DRV
DIM
COMP
CC
IN
SGND
L
1
MAX16838
DRAIN
PGND
C
1) Connect the bypass capacitor on V
2) Have a power ground plane for the switching-con-
s
LEDGND
L
close as possible to the device and connect the
capacitor ground to the analog ground plane using
vias close to the capacitor terminal. Connect SGND
of the device to the analog ground plane using a via
close to SGND. Lay the analog ground plane on the
inner layer, preferably next to the top layer. Use the
analog ground plane to cover the entire area under
critical signal components for the power converter.
verter power circuit under the power components
(input filter capacitor, output filter capacitor, induc-
tor, MOSFET, rectifier diode, and current-sense
resistor). Connect PGND to the power ground plane
as close to PGND as possible. Connect all other
ground connections to the power ground plane
using vias close to the terminals.
D
2
OV
NDRV
OUT1
OUT2
GATE
ISET
FLT
CS
RT
R2
R1
OV
OV
R
ISET
C
OUT
R
RT
R
CS
LED
STRINGS
CC
and DRV as
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