EUP3651
Layout Consideration
External Component
Due to the switching frequency and high transient
current of EUP3651, careful consideration of PCB
layout is necessary. The CIN should be connected as
close to the IC as possible. The ground of CIN and
COUT should be placed as close as possible. To achieve
the best performance of EUP3651, minimize the
distance between every two components and also
minimize every connection length with a maximum
trace width. Make sure each device connects to
immediate ground plane. A copper area matching the
TDFN exposed pad (TAB) must be connected to the
ground plane underneath. The use of multiple via
improves the package heat dissipation.
The driver requires two external 1µF ceramic
capacitors for decoupling input, output, and for the
charge pump. Both capacitors type X5R and X7R are
recommended for the LED driver application. In
charge pump modes, the input current ripple is kept
very low by design and an input bypass capacitor of
1µF is sufficient.
In 1X mode, the device operates in linear mode and
does not introduce switching noise back onto the
supply.
Applications Examples
I. Use the EUP3651 to drive four LEDs for one panel backlighting.
II. Use the EUP3651 to drive 3 LEDs for one panel backlighting. The unused channel should be connected to VOUT
.
DS3651 Ver1.0 Feb. 2008
10
EUTECH [ EUTECH MICROELECTRONICS INC ]
