AN3981 datasheet(4/54 Pages) STMICROELECTRONICS

4 / 54 page

List of figures

AN3981

4/54

Doc ID 022217 Rev 1

List of figures

Figure 1.

STMicroelectronics LED array drivers portfolio. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Figure 2.

STP04CM05 typical application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3.

STP04CM05 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 4.

Typical timing diagram for a 4-bit LED array driver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 5.

STP04CM05 output current vs. REXT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 6.

Typical application circuit for STP08xP05 devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Figure 7.

8-bit LED array driver block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Figure 8.

Typical timing diagram for an 8-bit LED array driver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Figure 9.

STP08CP05 and STP08DP05 output current vs. REXT . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Figure 10.

Fault conditions detected by error detection mode: a) shorted LED; b) open LED;

c) short-circuit from current generator to VLED; d) open channel; e) short-circuit from

current generator to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Figure 11.

Error status code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Figure 12.

Digital key for entering error detection mode in 8-bit LED drivers . . . . . . . . . . . . . . . . . . . 14

Figure 13.

Digital key for exiting error detection mode in 8-bit LED drivers . . . . . . . . . . . . . . . . . . . . . 14

Figure 14.

Example of error detection with OUT7 and OUT2 good and all other outputs faulty . . . . . 15

Figure 15.

Error detection results interpretation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Figure 16.

Failed error detection due to wrongly entered digital key . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Figure 17.

Typical application circuit for STP16xPyy05 devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Figure 18.

16-bit LED array driver block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Figure 19.

Typical timing diagram of a 16-bit LED array driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Figure 20.

Output current vs. REXT for a 16-bit LED array driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Figure 21.

Fault conditions detected by error detection mode: a) shorted LED; b) open LED;

c) short-circuit from current generator to VLED; d) open channel; e) short-circuit from

current generator to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 22.

Error status code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Figure 23.

Digital key for entering error detection mode in 16-bit LED drivers . . . . . . . . . . . . . . . . . . 22

Figure 24.

Digital key for exiting error detection mode in 16-bit LED drivers . . . . . . . . . . . . . . . . . . . . 22

Figure 25.

Example of error detection with OUT15 and OUT0 faulty and all other outputs good . . . . 23

Figure 26.

Error detection results interpretation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 27.

Typical application circuit for the STP24DP05 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 28.

STP24DP05 block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 29.

Typical timing diagram of the STP24DP05 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 30.

STP24DP05 output current vs. REXT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 31.

Fault conditions detected by error detection mode: a) shorted LED; b) open LED;

c) short-circuit from current generator to VLED; d) open channel; e) short-circuit from

current generator to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 32.

Error status code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 33.

Error detection through the DM pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 34.

Digital key for entering error detection mode in 32-bit LED drivers . . . . . . . . . . . . . . . . . . 31

Figure 35.

Digital key for exiting error detection mode in 32-bit LED drivers . . . . . . . . . . . . . . . . . . . . 31

Figure 36.

Example of error detection with the STP24DP05 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Figure 37.

Error detection results interpretation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 38.

Error flag and overtemperature flag pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Figure 39.

Data flow management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 40.

Gradual output delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 41.

Solution with single supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 42.

Solution with separated supply voltage for red LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

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