AN3981 datasheet(28/54 Pages) STMICROELECTRONICS

28 / 54 page

STP24DP05

AN3981

28/54

Doc ID 022217 Rev 1

Figure 30.

STP24DP05 output current vs. REXT

4.6

Error detection

The meaning of “error detection” is the detection of the faulty conditions that could occur on

each channel due to:

●

the LED, which can be damaged and behaves abnormally as a short or open circuit

●

any undesired event that can prevent the LED from working correctly (interruption of

the PCB - printed circuit board - trace connecting the LED to VLED or to the current

generator, short-circuit from current generator to ground or VLED).

All these possible events are summarized in Figure 41.

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

The diagnostic circuitry embedded in the STP24DP05 can detect these faulty conditions (in

accordance with the detection thresholds of Table 4) and provide the result of the detection

AN3981 Datasheet(PDF) 28 Page - STMicroelectronics