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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 (tPD = 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 (VIT ≤ 0.8 V: 20 mV steps /
VIT > 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 VIT 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 (tD) options ranging from 20 μs to 1200 ms and can monitor up to four channels while maintaining an ultra-low IQ current of 15 μA (maximum).
Texas Instruments carried out this assessment with respect to relevant requirements from the IEC 61508:2010 standard.
| IEC 61508:2010 | Requirement | Status | Compliance Argument | Evidence |
|---|---|---|---|---|
| Part 1: General Requirements | a. Documentation | Pass | All documentation follows TI Functional Safety Hardware development flow requirements. All documentation is planned in the functional safety plan. All documentation is following the TI functional safety templates. | TI Functional Safety Hardware development flow |
| Part 1: General Requirements | b. Management of Functional Safety | Pass | Project manager and Safety manager were appointed to this project. Functional Safety Plan was generated and necessary audits and assessments were scheduled. | Documented nomination of Functional Safety Manager |
| Part 1: General Requirements | c. Safety Lifecycle - Concept | Pass | Functional safety concept for the IC was developed with respect to the context of the targeted functional safety systems. | System Functional Safety Assumptions and Component Safety Requirements |
| Part 1: General Requirements | d. Safety Lifecycle - Overall Scope Definition | N/A | Requirements do not apply, however assumptions were made for the SEooC development. | N/A |
| Part 1: General Requirements | e. Safety Lifecycle - Hazard and Risk Analysis | N/A | Requirements do not apply, however assumptions were made for the SEooC development. | N/A |
| Part 1: General Requirements | f. Safety Lifecycle - Overall Safety Requirements | N/A | Requirements do not apply, however assumptions were made for the SEooC development. | N/A |
| Part 1: General Requirements | g. Safety Lifecycle - Overall Safety Requirements Allocation | Pass | Functional safety concept for the IC was developed with respect to the context of the targeted functional safety systems. | System Functional Safety Assumptions and Component Safety Requirements |
| Part 1: General Requirements | h. Safety Lifecycle - Overall Operation and Maintenance Planning | N/A | The requirements for overall operation and maintenance planning do not apply to this SEooC development. | N/A |
| Part 1: General Requirements | i. Safety Lifecycle - Overall Safety Validation Planning | Pass | These requirements were applied at the IC level, not the system level. IC functional safety requirements were planned to be validated in pre-silicon and post-silicon testing. | Validation and Characterization Plans |
| Part 1: General Requirements | j. Safety Lifecycle - Overall Installation and Commissioning | N/A | The requirements for overall installation and commissioning do not apply to this SEooC development. | N/A |
| Part 1: General Requirements | k. Safety Lifecycle - E/E/PE System Safety Requirements Specification | Pass | Functional safety concept for the IC was developed with respect to the context of the targeted functional safety systems. | Functional Safety Requirements Specification (SRS) |
| Part 1: General Requirements | l. Safety Lifecycle - E/E/PE Safety-Related Systems: Realization | Pass | IC functional safety requirements were realized in the product design. | Design Specification |
| Part 1: General Requirements | m. Safety Lifecycle - Other Risk Reduction Measures: Specification and Realization | N/A | The requirements for other risk reduction measures do not apply to this SEooC development. | N/A |
| Part 1: General Requirements | n. Safety Lifecycle - Overall Installation and Commissioning | N/A | The requirements for overall installation and commissioning do not apply to this SEooC development. | N/A |
| Part 1: General Requirements | o. Safety Lifecycle - Overall Safety Validation | Pass | These requirements were applied at the IC level, not the system level. IC functional safety requirements were planned to be validated in pre-silicon and post-silicon testing. | Validation and Characterization Plans |
| Part 1: General Requirements | p. Safety Lifecycle - Overall Operation, Maintenance and Repair | N/A | The requirements for overall operation, maintenance and repair do not apply to this SEooC development. | N/A |
| Part 1: General Requirements | q. Safety Lifecycle - Overall Modification and Retrofit | N/A | The requirements for overall modification and retrofit do not apply to this SEooC development. | N/A |
| Part 1: General Requirements | r. Safety Lifecycle - Decommissioning or Disposal | N/A | The requirements for decommissioning or disposal do not apply to this SEooC development. | N/A |
| Part 1: General Requirements | s. Verification | Pass | These requirements were applied at the IC level, not the system level. IC functional safety activities have been verified by persons of appropriate independence. | Verification Plans and Reports for each safety work product per Safety Plan |
| Part 1: General Requirements | t. Functional Safety Assessment | Pass | Refer to section 2 for a summary of the functional safety assessment. | Functional Safety Assessment |
| Part 2: Requirements for E/E/PE Safety-Related Systems | a. E/E/PE System Design Requirements Specification | Pass | These requirements were applied at the IC level, not the system level. IC functional safety requirements were generated from system assumptions. | System Functional Safety Assumptions and Requirements, SRS |
| Part 2: Requirements for E/E/PE Safety-Related Systems | b. E/E/PE System Safety Validation Planning | Pass | These requirements were applied at the IC level, not the system level. IC functional safety requirements were planned to be validated in pre-silicon and post-silicon testing. | Validation and Characterization Plans |
| Part 2: Requirements for E/E/PE Safety-Related Systems | c. E/E/PE System Design & Developments Including ASICs & Software | Pass | These requirements were applied at the IC level, not the system level. IC functional safety requirements were realized in the product design. | Design Specification |
| Part 2: Requirements for E/E/PE Safety-Related Systems | d. E/E/PE System Integration | N/A | The requirements for system integration do not apply to this SEooC development. | N/A |
| Part 2: Requirements for E/E/PE Safety-Related Systems | e. E/E/PE System Installation, Commissioning, Operation and Maintenance Procedures | N/A | The requirements for system installation, commissioning, operation and maintenance do not apply to this SEooC development. | N/A |
| Part 2: Requirements for E/E/PE Safety-Related Systems | f. E/E/PE System Safety Validation | Pass | These requirements were applied at the IC level, not the system level. IC functional safety requirements have been validated in pre-silicon and post-silicon testing. | Validation and Characterization Plans and Reports |
| Part 2: Requirements for E/E/PE Safety-Related Systems | g. E/E/PE System Modification | N/A | The requirements for system modification do not apply to this SEooC development. | N/A |
| Part 2: Requirements for E/E/PE Safety-Related Systems | h. E/E/PE System Verification | Pass | These requirements were applied at the IC level, not the system level. IC functional safety activities have been verified by persons of appropriate independence. | Verification Plans and Reports for each safety work product per Safety Plan |
| Part 2: Requirements for E/E/PE Safety-Related Systems | i. E/E/PE System Functional Safety Assessment | Pass | Refer to section 2 for a summary of the functional safety assessment. | Functional Safety Assessment |
| Part 3: Software Requirements | All sections | N/A | There are no software requirements for this SEooC development. | N/A |
| Part 4: Definitions and Abbreviations | No requirements in this part | N/A | There are no requirements in IEC 61508-4. | N/A |
| Part 5: Examples of Methods for the Determination of Safety Integrity Levels | No requirements in this part | N/A | IEC 61508-5 is an informative reference. There are no requirements in IEC 61508-5, however the analysis techniques that are recommended by this part are incorporated into the TI Functional Safety Hardware work product templates that have been used for this project. | N/A |
| Part 6: Guidelines on the Application of IEC 61508-2 and IEC 61508-3 | No requirements in this part | N/A | IEC 61508-6 is an informative reference. There are no requirements in IEC 61508-6, however the analysis techniques that are recommended by this part are incorporated into the TI Functional Safety Hardware work product templates that have been used for this project. | N/A |
| Part 7: Overview of Techniques and Measures | No requirements in this part | N/A | IEC 61508-7 is an informative reference. There are no requirements in IEC 61508-7, however the analysis techniques that are recommended by this part are incorporated into the TI Functional Safety Hardware work product templates that have been used for this project. | N/A |