CAT4106_14 Datasheet, PDF (12/15 Pages) ON Semiconductor – 6 W Quad Channel DC/DC LED Driver

CAT4106
Application Information
External Component Selection
Capacitors
The CAT4106 requires small ceramic capacitors of 1 mF
on the VIN pin (C1), 4.7 mF on the inductor input (C2), and
10 mF on the output (C3). Under normal condition, a 4.7 mF
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 mH 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. Coiltronics DR73−470 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 1 A 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 29. Recommended Layout for TQFN−16
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