SFFS172 August   2021 REF20-Q1

 

  1.   Trademarks
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
  4. 3Failure Mode Distribution (FMD)
  5. 4Pin Failure Mode Analysis (Pin FMA)

4 Pin Failure Mode Analysis (Pin FMA)

This section provides a Failure Mode Analysis (FMA) for the pins of the REF20-Q1. 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.

Table 4-1 TI Classification of Failure Effects
CLASSFAILURE EFFECTS
APotential device damage that affects functionality
BNo device damage, but loss of functionality
CNo device damage, but performance degradation
DNo device damage, no impact to functionality or performance

Figure 4-1 shows the REF20-Q1 pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the REF20-Q1data sheet.

GUID-59AC01BA-7E0E-4C0C-B0C0-92DD2D0A1B33-low.gif Figure 4-1 Pin Diagram

Unless otherwise specified, it is assumed that the voltages applied to all the pins are within the Recommended Operating Range specified in the datasheet.

Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
PIN NAMEPIN NO.DESCRIPTION OF POTENTIAL FAILURE EFFECT(S)FAILURE EFFECT CLASS
VBIAS1Might damage the device, can affect functionality. Forces short circuit current to flow through device.A
GND2Normal operation.D
EN3No device damage. Device output will be disabled. System current may increase.B
VIN4No device damage. Device will not generate output. Increased system current.B
VREF5Might damage the device, can affect functionality. Forces short circuit current to flow through device.A
Table 4-3 Pin FMA for Device Pins Open-Circuited
PIN NAMEPIN NO.DESCRIPTION OF POTENTIAL FAILURE EFFECT(S)FAILURE EFFECT CLASS
VBIAS1No bias output voltage.B
GND2No output voltage.B
EN3No damage to device, can affect functionality.B
VIN4Device is unpowered.B
VREF5No reference output voltage.B
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
PIN NAMEPIN NO.SHORTED TODESCRIPTION OF POTENTIAL FAILURE EFFECT(S)FAILURE EFFECT CLASS
VBIAS1GNDMight damage the device, can affect functionality. Forces short circuit current to flow through device.A
GND2ENNo device damage. Device output will be disabled.B
EN3VINNo damage to device. Device disable functionality will be lost. System current may increase.B
VIN4VREFMight damage the device. High current flow into the reference output.A
VREF5VBIASMight damage the device. High current will flow from reference output to bias output.A
Table 4-5 Pin FMA for Device Pins Short-Circuited to VIN Supply
PIN NAMEPIN NO.DESCRIPTION OF POTENTIAL FAILURE EFFECT(S)FAILURE EFFECT CLASS
VBIAS1Might damage the device. High current flow into the bias output.A
GND2No device damage. Device will not generate output. Increased system current.B
EN3No damage to device. Device disable functionality will be lost. System current may increase.B
VIN4Normal operation.D
VREF5Might damage the device. High current flow into the bias output.A