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

4.1 HTSSOP-20 Package

Figure 4-1 shows the HTSSOP-20 pin diagram for the LM26420-Q1 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 (HTSSOP-20 Package)Figure 4-1 Pin Diagram (HTSSOP-20 Package)
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin NamePin No.Description of Potential Failure EffectsFailure Effect Class
VINC1Device does not power up.B
EN12Intended functionality if converter 1 is shutdown.D
VIND13Device does not power up.B
VIND14Device does not power up.B
SW15Potential device damage.A
PGND16No effect.D
PGND17No effect.D
FB18Output voltage regulated to VIN (100% mode).B
PG19Intended functionality if PG1 is not used.D
DAP10No effect.D
DAP11No effect.D
PG212Intended functionality if PG2 is not used.D
FB213Output voltage regulated to VIN (100% mode).B
PGND214No effect.D
PGND215No effect.D
SW216Potential device damage.A
VIND217Device does not power up.B
VIND218Device does not power up.B
EN219Intended functionality if converter 2 is shutdown.D
AGND20No effect.D
DAP-No effect.D
Table 4-3 Pin FMA for Device Pins Open-Circuited
Pin NamePin No.Description of Potential Failure EffectsFailure Effect Class
VINC1Device is not functional.B
EN12Undetermined device status, device potentially does not power up.B
VIND13Device does not power up.B
VIND14Device does not power up.B
SW15Converter 1 is not functional, open loop operation.B
PGND16Device is not functional.B
PGND17Device is not functional.B
FB18Undetermined converter 1 output voltage.B
PG19Intended functionality if PG1 is not used.D
DAP10Functional but impact on thermal behavior and reliability.C
DAP11Functional but impact on thermal behavior and reliability.C
PG212Intended functionality if PG2 is not used.D
FB213Undetermined converter 2 output voltage.B
PGND214Device is not functional.B
PGND215Device is not functional.B
SW216Converter 2 is not functional, open loop operation.B
VIND217Device does not power up.B
VIND218Device does not power up.B
EN219Undetermined device status, device potentially does not power up.B
AGND20Device is not functional.B
DAP-Functional but impact on thermal behavior and reliability.C
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Pin NameShorted toDescription of Potential Failure EffectsFailure Effect Class
VINCEN1Intended functionality.D
EN1VIND1Intended functionality.D
VIND1VIND1Redundant pin.D
VIND1SW1Potential device damage.A
SW1PGND1Potential device damage.A
PGND1PGND1Redundant pin.D
PGND1FB1Output voltage regulated to VIN (100% mode).B
FB1PG1Potential device damage.A
PG1DAPIntended functionality if PG1 is not used.D
DAPPG2Intended functionality if PG2 is not used.D
PG2FB2Potential device damage.A
FB2PGND2Output voltage regulated to VIN (100% mode).B
PGND2PGND2Redundant pin.D
PGND2SW2Potential device damage.A
SW2VIND2Potential device damage.A
VIND2VIND2Redundant pin.D
VIND2EN2Intended functionality.D
EN2AGNDIntended functionality if converter 2 is shutdown.D
Table 4-5 Pin FMA for Device Pins Short-Circuited to Supply
Pin NamePin No.Description of Potential Failure EffectsFailure Effect Class
VINC1Intended functionality.D
EN12Intended functionality.D
VIND13Intended functionality.D
VIND14Intended functionality.D
SW15Potential device damage.A
PGND16Device does not power up.B
PGND17Device does not power up.B
FB18Potential device damage.A
PG19PG does not indicate the status.B
DAP10Device does not power up.B
DAP11Device does not power up.B
PG212PG does not indicate the status.B
FB213Potential device damage.A
PGND214Device does not power up.B
PGND215Device does not power up.B
SW216Potential device damage.A
VIND217Intended functionality.D
VIND218Intended functionality.D
EN219Intended functionality.D
AGND20Device does not power up.B
DAP-Device does not power up.B