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This document contains information for the ISOTMP35-Q1 (DFQ package) to aid in functional safety system designs. This document discusses:
Figure 1-1 shows the device functional block diagram for reference.
The ISOTMP35-Q1 was developed using a quality-managed development process, but was not developed in accordance with the ISO 26262 standards.
This section provides functional safety failure in time (FIT) rates for ISOTMP35-Q1 based on two different industry-wide used reliability standards:
FIT IEC TR 62380 / ISO 26262 | FIT (Per 109 Hours) |
---|---|
Total Component FIT Rate |
8 |
Die FIT Rate | 2 |
Package FIT Rate |
6 |
The failure rate and mission profile information in Table 2-1 comes from the reliability data handbook IEC TR 62380 / ISO 26262 part 11:
Table | Category | Reference FIT Rate | Reference Virtual TJ |
---|---|---|---|
5 | CMOS/BICMOS ASICs Analog & Mixed ≤ 50V supply | 25 | 55 |
The reference FIT rate and reference virtual TJ (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.
The failure mode distribution estimation for ISOTMP35-Q1 in Table 3-1 comes from the combination of common failure modes listed in standards such as IEC 61508 and ISO 26262, the ratio of sub-circuit function size and complexity, and from best engineering judgment.
The failure modes listed in this section reflect random failure events and do not include failures due to misuse or overstress.
Die Failure Modes | Failure Mode Distribution (%) |
---|---|
VOUT open (HIZ) | 20% |
VOUT short to VDD | 10% |
VOUT short to GND | 10% |
VOUT not in specification | 60% |
The FMD in Table 3-1 excludes short-circuit faults across the isolation barrier. Faults for short circuits across the isolation barrier can be excluded according to ISO 61800-5-2:2016 if the following requirements are fulfilled:
Apply creepage and clearance requirements according to the specific equipment isolation standards of an application. Care must be taken to maintain the creepage and clearance distance of a board design to ensure that the mounting pads of the isolator on the printed-circuit board do not reduce this distance.