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DA1634.001

28 November, 2008

BLOCK DIAGRAM

&

VDD1

VDD2

GND1

GND2

IN1

IN2

IN3

IN4

XPD

DUMMY

OUT1

OUT2

OUT3

OUT4

MAS1634

4 x LED Driver

Figure 1.

MAS1634 Block Diagram

Figure

1

presents

MAS1634

block

diagram.

MAS1634 consists of four fixed current sink outputs

for driving VDD connected LEDs. Each LED driver

can be turned on or off independently. There is also

common power-down control pin XPD which is

active when low.

The dummy pad is electrically unconnected and its

only purpose is to make the pad layout symmetrical

which helps in making the flip-chip connection even

more reliable.

VDD1 and VDD2 power supply pins are internally

connected

making

only

one

supply

voltage

connection necessary. Also GND1 and GND2 pins

are internally connected so that it is necessary to

connect only one of the two ground pins to supply

ground.