4.11

Support to ISO26262

Even if not designed as the safety HW element, the device contains some features that can be used to support

the application that needs to fulfill functional safety requirements. Analysis of the IC’s capability to reach the

required safety level, should be made at system level under user responsibility.

The following device safety requirements have been considered for a typical application:

Table 14. Safety requirement

ID

Description

SR-001

Operation of voltage regulator is allowed until over the temperature limit.

SR-002

Operation of voltage regulator is enabled until the programmed current limit is

reached.

SR-003

Output voltage of regulator shall remain within programmed range when the RST

pin is not asserted.

SR-004

Output voltage of the regulator shall remain within programmed range when the

square wave at the TW pin is not generated.

Based on the above requirements list the following safety mechanism has been implemented:

Table 15. Implemented safety mechanism

ID

Description

SR covered

SM1

Thermal sensor acting by the TW pin

SR-004

SM2

Overtemperature protection

SR-001

SM3

Limitation on maximum output current

SR-002

SM4

Output voltage VO monitoring for

undervoltage detection

SR-002

SM5

Output voltage VO monitoring for

overvoltage detection

SR-002

SM6

RST reset assertion in case of VO

undervoltage detection

SR-003

In addition to the internal watchdog for checking the correct operation of the microcontroller, it can be considered

a system-level safety mechanism.

More details about functional safety can be found in the device safety manual, provided on customer request.

L99VR02J

Support to ISO26262

DS14076 - Rev 1

page 26/38