The purpose of the Functional Safety Report is to summarize the results from analysis and documentation involved in the development of this project and to determine the results are sufficient to claim compliance to the identified functional safety standards. This high level overview is intended to be used by customers as a part of their safety case with respect to the TPS3704x-Q1.

This functional safety assessment has shown the Texas Instruments TPS3704x-Q1 project to be satisfactorily compliant with the relevant sections of functional safety standard ISO-26262 up to ASIL-A and IEC61508 up to SIL-1 requirements.

The tailored development process used for this development, SafeTI Functional Safety Hardware, complies with the relevant requirements for functional safety management.

The work products developed for this project are sufficient to prove that this development process was followed and that the project complies with the relevant sections of ISO 26262 and IEC 61508.

The FMEDA analysis shown that the SPFM, LFM, and PMHF are within the limits required by ISO 26262-5 Tables 5, 6, and 7 to achieve ASIL-A and IEC 61508-2 tables 2 and 3 to achieve SIL-1.

The TPS3704x-Q1 passes the assessment. This assessment applies to all part numbers as given in the device naming convention figure.For non automotive grade parts remove the -Q1 from the part number.

The TPS3704x is a family of quad, triple, dual, and single precision voltage supervisors where each channel has overvoltage and undervoltage detection capability. The TPS3704x features a highly accurate window threshold voltage where the upper and lower thresholds can be customized for symmetric or asymmetric tolerances. The reset signal for the TPS3704x is asserted, with a fault detection time delay (t_PD = 10 μs maximum), when the sense voltage is outside of the overvoltage and undervoltage thresholds.

The TPS3704x includes the resistors used to set the overvoltage and undervoltage thresholds internal to the device. These internal resistors allow for lower component counts and greatly simplifies the design because no additional margins are needed to account for the accuracy of external resistors. The level of integration in the TPS3704x enables a total small solution size for any application.

The TPS3704x is capable to monitor any voltage rail with high resolution (V_IT ≤ 0.8 V: 20 mV steps /
V_IT > 0.8 V: 0.5% or 20 mV steps whichever is lower). Each channel in the TPS3704x can be configured independently as a window, OV or UV supervisor. Also, the V_IT threshold voltage for each channel can be asymmetric. For example, a channel that is configured as an overvoltage supervisor can be setup with a +5% tolerance whereas an undervoltage channel supervisor can be programmed with a -4% tolerance. If a window supervisor is configured, the voltage threshold tolerance can either be symmetrical or asymmetrical.

The TPS3704x includes fixed reset time delay (t_D) options ranging from 20 μs to 1200 ms and can monitor up to four channels while maintaining an ultra-low I_Q current of 15 μA (maximum).