TLC5944

TERMINAL FUNCTIONS

TERMINAL

NAME

PWP

RHB

I/O

DESCRIPTION

SIN

5

2

I

Serial data input for grayscale and dot correction.

Serial data shift clock for GS shift register and DC shift register. Schmitt buffer input. The shift

register is selected by the DCSEL pin. Data present on the SIN pin are shifted into the shift

SCLK

4

1

I

register selected by DCSEL with the rising edge of the SCLK pin. Data in the selected shift

register are shifted to the MSB side by 1-bit synchronizing to the rising edge of SCLK. The MSB

data of the selected register appears on SOUT.

Data in the GS and DC shift register are moved to the respective data latch with a low-to-high

XLAT

3

32

I

transition of this pin.

Shift register and data latch select. When DCSEL is low, SCLK/XLAT/SOUT are connected to the

DCSEL

6

3

I

GS shift register and data latch. When DCSEL is high, SCLK/XLAT/SOUT are connected to the

DC shift register and data latch. DCSEL should not be changed while SCLK is high.

Reference clock for grayscale PWM control. If BLANK is low, then each rising edge of GSCLK

GSCLK

25

24

I

increments the grayscale counter for PWM control.

Blank (all constant current outputs off). When BLANK is high, all constant current outputs (OUT0

through OUT15) are forced off, the grayscale counter is reset to '0', and the grayscale PWM

BLANK

2

31

I

timing controller is initialized. When BLANK is low, all constant current outputs are controlled by

the grayscale PWM timing controller.

Constant current value setting. OUT0 through OUT15 sink constant current is set to the desired

IREF

27

26

I/O

value by connecting an external resistor between IREF and GND.

Serial data output for GS, DC, and status information data (SID). This output is connected to the

SOUT

24

23

O

MSB of the shift register selected by DCSEL.

Error output. Open-drain output. XERR goes low when LOD or TEF are set. XERR is in high

XERR

23

22

O

impedance when error free.

Constant current output. Each output can be tied to other outputs to increase the constant

OUT0

7

4

O

current.

OUT1

8

5

O

Constant current output

OUT2

9

6

O

Constant current output

OUT3

10

7

O

Constant current output

OUT4

11

8

O

Constant current output

OUT5

12

9

O

Constant current output

OUT6

13

10

O

Constant current output

OUT7

14

11

O

Constant current output

OUT8

15

14

O

Constant current output

OUT9

16

15

O

Constant current output

OUT10

17

16

O

Constant current output

OUT11

18

17

O

Constant current output

OUT12

19

18

O

Constant current output

OUT13

20

19

O

Constant current output

OUT14

21

20

O

Constant current output

OUT15

22

21

O

Constant current output

VCC

28

27

—

Power-supply voltage

VUP

26

25

—

Pre-charge FET power supply

GND

1

30

—

Power ground

12, 13,

NC

—

—

No internal connection

28, 29

8

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Product Folder Link(s): TLC5944