AUTO OUTPUT OFF

BLANK

GSCLK

OUTnVoltage

(GSData=FFFd)

LODDataLatch

(Internal)

XERR

ICC

1

2

3

31

32

33

34

35

4096

1

2

3

31

32

33

34

35

4096

0(PreviousData)

1( pd

U

at dD ta)

e

a

Aut

O

o

uput

f

t

O f

V

<V

OUTn

LOD

THERMAL ERROR FLAG (TEF)

'0'

BLANK

TEF

(Internal)

XERR

GSCLK

1

3

2

1

2

3

4

T <T

J

TEF

T

T

³

J

TEF

T <T

T

-

J

TEF

HYS

T

T

³

J

TEF

'0'

'1'

Hi-Z

Low

SCLK

ICJunction

Temperature(T )

J

XLAT

TLC5946

to ground LED at OUTn, the TLC5946 turns off OUTn to reduce the ICC at the 33rd falling edge of GSCLK after

the falling edge of BLANK, as shown in Figure 28. This feature minimizes supply current during fault conditions.

If there are any unconnected output LED lamps (including connection failures or short-circuits), the grayscale

data corresponding to the unconnected output should be set to '0' before turning on the LEDs.

Figure 28. LOD and Auto Output Off Timing

The TLC5946 has a thermal error flag (TEF) function to indicate an over-temperature condition. If the junction

temperature exceeds the threshold temperature, +162°C typical, TEF toggles to '1' and the XERR pin goes to a

low level. Once TEF becomes '1', it remains a '1' until the first falling edge of SCLK after XLAT goes low, as

'1', even after the first falling edge of SCLK. TEF is also shifted out of the SOUT pin; see the Status Information

Data (SID) section.

Figure 29. TEF and XERR Timing

Copyright © 2008, Texas Instruments Incorporated

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