AN2478

Evaluation boards with error detection features using STP08DP05 LED drivers

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5

Evaluation boards with error detection features using

STP08DP05 LED drivers

5.1

Description

The main aim of this section is to demonstrate two evaluation boards with error detection

features using the new STP08DP05 LED drivers: the STEVAL-ILL002V3 with OSRAM LEDs

and the STEVAL-ILL002V4 with VISHAY LEDs (Figure 12). The evaluation boards are

completely based on an existing solution already described in AN2415, because drivers

were replaced by the new STP08DP05. Therefore this section is focused on explaining only

the differences in the main features and timing diagram.

Main features of the evaluation board are:

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Brightness regulation

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Blinking speed regulation

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Animated text

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Error detection on outputs

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PC graphic user interface for error detection(GUI)

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DC/DC converter using the L5970D

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Input voltage range of 7 V to 32 V

Two versions of the evaluation boards are available:

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STEVAL-ILL002V3 using OSRAM LEDs

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STEVAL-ILL002V4 using VISHAY LEDs

Figure 12.

STEVAL-ILL002V3 or 4 evaluation boards

5.2

Timing diagram

The heart of this application is the microcontroller (ST7LITE39) which sends the data

through the SPI to the LED drivers. There are five STP08DP05 LED drivers each with eight

outputs assembled to allow independent driving of 40 LEDs during normal operational mode

and also to detect the status of incorrect LEDs during error detection mode. The

implementation method is described in the timing diagrams in this document.