AS1181 datasheet(33/92 Pages) AMSOSRAM

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AS1181

Functional description

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DS001139 • v3-00 • 2026-Apr-01

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7.2.3.2

Strobe rate monitor in STROBE mode

The strobe rate monitor measures the applied strobe signal frequency and compares it to the

value stored in TD_TRATE_MAX register (Address 0x1A34). If the applied strobe signal is too

fast, an interrupt is set to inform the host. Note that the strobe rate monitor is not available in

direct PWM mode with 1 or 2 inputs.

7.2.4

BIST (Built-in-self test)

A built-in-self test is implemented to check the device safety monitors.

After power-on-reset the digital BIST is checking RAM, ROM and OTP followed by the analog

BIST checking the following circuits:

1. VLED voltage monitor and error injection to test comparator toggling.

2. VP18 voltage monitor and error injection to test comparator toggling.

3. Temperature monitor and error injection to test comparator toggling.

4. LN shorts and open tests.

5. LN comparator and error injection to test comparator toggling.

6. LP shorts and open tests.

7. LP comparator error and error injection to test comparator toggling.

8. High-side power switch / Overcurrent detection" circuit operation.

Note: Error injection tests are done after power on-reset only while LNx & LP short/open tests

are done continuously.

After the BIST sequence has been completed successfully the device enters IDLE mode and

illumination can be started. If a failure occurs during the BIST sequence, the device enters

FAULT state and corresponding interrupt bit is set to inform the host.

AS1181 Datasheet(PDF) 33 Page - ams-OSRAM AG