4 Pin Failure Mode Analysis (Pin FMA)

This section provides a failure mode analysis (FMA) for the pins of the LM5168 and LM5169. The failure modes covered in this document include the typical pin-by-pin failure scenarios:

• Pin short-circuited to ground (see Table 4-2)
• Pin open-circuited (see Table 4-3)
• Pin short-circuited to an adjacent pin (see Table 4-4)
• Pin short-circuited to supply (see Table 4-5)

Table 4-2 through Table 4-5 also indicate how these pin conditions can affect the device as per the failure effects classification in Table 4-1.

Figure 4-1 shows the LM5168 and LM5169 pin diagram. For a detailed description of the device pins, see the Pin Configuration and Functions section in the LM5168 and LM5169 data sheet.

Figure 4-1 Pin Diagram

Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:

• Device used within the Recommended Operating Conditions and the Absolute Maximum Ratings found in the LM5169-Q1/LM5168-Q1 0.65-A/0.3-A, 120-V, Step-Down Converter with Fly-Buck™ Converter Capability Data Sheet
• Configuration as shown in the Example Application Circuit found in the LM5169-Q1/LM5168-Q1 0.65-A/0.3-A, 120-V, Step-Down Converter with Fly-Buck™ Converter Capability Data Sheet.
• Valid for an ambient temperature of 25ºC.
• Faults applied after device start-up is complete.