This document contains information for DRV8705-Q1 (VQFN 32 pin package package) to aid in a functional safety system design. Information provided are:

• Functional Safety Failure In Time (FIT) rates of the semiconductor component estimated by the application of industry reliability standards
• Component failure modes and their distribution (FMD) based on the primary function of the device
• Pin failure mode analysis (Pin FMA)

Figure 1-1 shows the device functional block diagram for the SPI variant as a reference.

Figure 1-1 DRV8705S-Q1 Functional Block Diagram

Figure 1-2 shows the device functional block diagram for the HW variant as a reference.

Figure 1-2 DRV8705H-Q1 Functional Block Diagram

DRV8705-Q1 was developed using a quality-managed development process, but was not developed in accordance with the IEC 61508 or ISO 26262 standards.

This section provides Functional Safety Failure In Time (FIT) rates for DRV8705-Q1 based on two different industry-wide used reliability standards:

• Table 2-1 provides FIT rates based on IEC TR 62380 / ISO 26262 part 11
• Table 2-2 provides FIT rates based on the Siemens Norm SN 29500-2

The failure rate and mission profile information in Table 2-1 comes from the Reliability data handbook IEC TR 62380 / ISO 26262 part 11:

• Mission Profile: Motor Control from Table 11
• Power dissipation: 250 mW
• Climate type: World-wide Table 8
• Package factor (lambda 3): Table 17b
• Substrate Material: FR4
• EOS FIT rate assumed: 0 FIT

The Reference FIT Rate and Reference Virtual T_J (junction temperature) in Table 2-2 come from the Siemens Norm SN 29500-2 tables 1 through 5. Failure rates under operating conditions are calculated from the reference failure rate and virtual junction temperature using conversion information in SN 29500-2 section 4.