SNVA961A May   2020  – November 2024 LM26420-Q1

 

  1.   1
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
    1. 2.1 HTSSOP-20 Package
    2. 2.2 WQFN-16 Package
  4. 3Failure Mode Distribution (FMD)
  5. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 HTSSOP-20 Package
    2. 4.2 WQFN-16 Package
  6. 5Revision History

4.2 WQFN-16 Package

Figure 4-2 shows the LM26420-Q1 pin diagram for the WQFN-16 package. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the LM26420-Q1 data sheet.

LM26420-Q1 Pin Diagram (WQFN-16 Package)Figure 4-2 Pin Diagram (WQFN-16 Package)
Table 4-6 Pin FMA for Device Pins Short-Circuited to Ground
Pin NamePin No.Description of Potential Failure EffectsFailure Effect Class
VIND11Device does not power up.B
VIND12Device does not power up.B
SW13Potential device damage.A
PGND14No effect.D
FB15Output voltage regulated to VIN (100% mode).B
PG16Intended functionality if PG1 is not used.D
PG27Intended functionality if PG2 is not used.D
FB28Output voltage regulated to VIN (100% mode).B
PGND29No effect.D
SW210Potential device damage.A
VIND211Device does not power up.B
VIND212Device does not power up.B
EN213Intended functionality if converter 2 is shutdown.D
AGND14No effect.D
VINC15Device does not power up.B
EN116Intended functionality if converter 1 is shutdown.D
DAP-No effect.D
Table 4-7 Pin FMA for Device Pins Open-Circuited
Pin NamePin No.Description of Potential Failure EffectsFailure Effect Class
VIND11Device does not power up.B
VIND12Device does not power up.B
SW13Converter 1 not functional, open loop operation.B
PGND14Device is not functional.B
FB15Undetermined converter 1 output voltage.B
PG16Intended functionality if PG1 is not used.D
PG27Intended functionality if PG2 is not used.D
FB28Undetermined converter 2 output voltage.B
PGND29Device is not functional.B
SW210Converter 2 not functional, open loop operation.B
VIND211Device does not power up.B
VIND212Device does not power up.B
EN213Undetermined device status, device potentially does not power up.B
AGND14Device is not functional.B
VINC15Device is not functional.B
EN116Undetermined device status, device potentially does not power up.B
DAP-Functional but impact on thermal behavior and reliability.C
Table 4-8 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Pin NameShorted toDescription of Potential Failure EffectsFailure Effect Class
VIND1VIND1Redundant pin.D
VIND1SW1Potential device damage.A
SW1PGND1Potential device damage.A
FB1PG1Potential device damage.A
PG1PG2PG output can be wrong.C
PG2FB2Potential device damage.A
PGND2SW2Potential device damage.A
SW2VIND2Potential device damage.A
VIND2VIND2Redundant pin.D
EN2AGNDIntended functionality if converter 2 is shutdown.D
AGNDVINCDevice does not power up.B
VINCEN1Intended functionality.D
Table 4-9 Pin FMA for Device Pins Short-Circuited to Supply
Pin NamePin No.Description of Potential Failure EffectsFailure Effect Class
VIND11Intended functionality.D
VIND12Intended functionality.D
SW13Potential device damage.A
PGND14Device does not power up.B
FB15Potential device damage.A
PG16PG does not indicate the status.B
PG27PG does not indicate the status.B
FB28Potential device damage.A
PGND29Device does not power up.B
SW210Potential device damage.A
VIND211Intended functionality.D
VIND212Intended functionality.D
EN213Intended functionality.D
AGND14Device does not power up.B
VINC15Intended functionality.D
EN116Intended functionality.D
DAP-Device does not power up.B