Datasheet

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C1+

SDAT DS1 DS2 DM5

VIO

GND

NC-G

DM1DM2DM3DM4IS

ENA

GND

C2+

C2-

C1-

VOUT

VIN

MainDisplay

C2 C3

1 Fm

SubDisplay

SCLK

CInterface

1.8VforI/O

Input

AuxiliaryPortforKeyPad

orFlashLight

562kW

330 W

1 Fm

4.7 Fm

LAYOUT GUIDELINES

TPS60251

SLVS767C – APRIL 2007 – REVISED NOVEMBER 2007

Figure 21. The Typical Application Circuit for Sub, Main, and Keypad Backlight

Figure 21 shows the typical application circuit for sub, main, and keypad backlight. In this application, DM5 is

assigned as the auxiliary input for the keypad lighting application.

There are several points to consider when laying out a PCB for charge pump based solutions. In general, all

capacitors should be as close as possible to the device. This is especially important when placing the flying

capacitors (C2, C3 in Figure 20 and Figure 21 ). To provide accurate WLED current, the current path with the

current setting resistor must be short to avoid any interference from other switching components. In cases where

DM5 is assigned for torch/flash applications, with a maximum 80-mA WLED current, this current path must be

kept wide to reduce the trace resistance.

Product Folder Link(s): TPS60251