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SILICON TOUCH TECHNOLOGY INC.

DM164

8x3-CHANNEL CONSTANT CURRENT LED DRIVERS

Version:A.002

Page 13

Open Detection

If there is any one of the 24 LEDs open or disconnected, the DM164 can detect and report

the error. The open detection circuit works when the following two conditions are met

simultaneously:

1. IOUTn is on (IOUTn > 200ns and EN_B=”L”).

2. When the output voltage at IOUTn is less than 0.2 V

The open error signal (OPE) has two methods to communicate the error signals to the

system. One is through serial output data to indicate which channel has failure (OPEn=H

=> IOUTn is open). The other is by means of dedicated Alarm pin when EN_B=L.

Status Information Output

When the DM164 operates at GD mode, after the LTH signal latches the input data from

shift registers to the data latches, the shift registers data will be replaced by the status

information. The status information includes the thermal error signals (Shutdown, T130

and T170,), open error signals (OPE) and dot correction data (DC), which will be

transferred out from DOUT pin. Figure 6 shows the status information format.

(a. IOUT shut down => Shut down=L, b. Tj>130℃ => T130=H, c. Tj>170℃ => T170=H)

‧

‧

‧

‧

‧

‧

‧

‧

‧

383

MSB

377

OPE

23

376

DC IOUT23

8-bit

Shut

down

T130

T170

375

374

373

X

368

8-bit

16-bit

OPE

22

367

361

360

DC IOUT22

8-bit

X

X

359

352

Reserved

16-bit

OPE

21

351

345

344

DC IOUT21

8-bit

X

X

343

336

Reserved

16-bit

OPE

19

319

313

312

DC IOUT19

8-bit

X

X

311

304

Reserved

16-bit

OPE

18

303

297

296

DC IOUT18

8-bit

X

X

295

288

Reserved

16-bit

OPE

20

335

329

328

DC IOUT20

8-bit

X

X

327

320

Reserved

16-bit

OPE

01

31

25

24

DC IOUT01

8-bit

X

X

23

16

Reserved

16-bit

OPE

00

15

9

8

DC IOUT00

8-bit

X

X

70

Reserved

16-bit

OPE

02

47

41

40

DC IOUT02

8-bit

X

X

39

32

Reserved

16-bit

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

...

DC[6]

23

DC[0]

23

DC[6]

22

DC[0]

22

DC[6]

21

DC[0]

21

DC[6]

18

DC[0]

18

DC[6]

19

DC[0]

19

DC[6]

20

DC[0]

20

DC[6]

00

DC[0]

00

DC[6]

01

DC[0]

01

DC[6]

02

DC[0]

02

Figure 6. Status Information Data Format (ER[383:0])