CAT4106HV4-GT2 Datasheet, PDF (13/17 Pages) ON Semiconductor – 6W Quad Channel DC/DC LED Driver with Diagnostics

CAT4106
APPLICATION INFORMATION
External Component Selection
Capacitors
The CAT4106 requires small ceramic capacitors of
1 µF on the VIN pin (C1), 4.7 μF on the inductor input
(C2), and 10 µF on the output (C3). Under normal
condition, a 4.7 µF input capacitor (C2) is sufficient.
The voltage rating of each capacitor should be
compatible with the maximum voltage applied. For the
output, a 50 V rated capacitor (C3) is recommended in
case the LED becomes disconnected (Open-LED
condition). X5R and X7R capacitor types are ideal due
to their stability across temperature range.
Inductor
A 47 µH inductor is recommended for most
applications. In cases where the efficiency is critical,
inductances with lower series resistance are
preferred. Inductors with current rating of 1 A or higher
are recommended for most applications. Coilcraft
CR73-470 inductor rated at 1.08 A is recommended
for most applications.
Schottky Diode
The current rating of the Schottky diode (D) must
exceed the peak current flowing through it. A 1A rated
Schottky diode is recommended. The Schottky diode
performance is rated in terms of its forward voltage at a
given current. In order to achieve the best efficiency,
this forward voltage should be as low as possible. The
response time is also critical since the driver is
operating at 1 MHz. NXP PMEG6010CEJ (60 V / 1 A
rated) Schottky barrier rectifier is recommended for
most applications.
Recommended Layout
The board layout should provide good thermal
dissipation through the PCB. Multiple via can be used
to connect the tab of the CAT4106 to a large ground
plane underneath the package.
Input capacitor C1 should be placed as close to the
driver IC as possible. The RSET resistor (R1) and
channel voltage setting resistor (R3) should have a
Kelvin connection to the GND pin of the CAT4106.
Figure 9. Recommended Layout for TQFN-16
© 2009 SCILLC. All rights reserved.
13
Characteristics subject to change without notice
Doc. No. MD-5037, Rev. A