SFFS755 November   2023 SN74HCS14-Q1

 

  1.   1
  2.   Trademarks
  3. 1Overview
  4. 2Functional Safety Failure In Time (FIT) Rates
    1. 2.1 BQA, D, DYY, and PW Packages
  5. 3Failure Mode Distribution (FMD)
  6. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 BQA, D, DYY, and PW Packages
  7. 5Revision History

4.1 BQA, D, DYY, and PW Packages

Figure 4-2 shows the SN74HCS14-Q1 pin diagram for the BQA, D, DYY, and PW packages. For a detailed description of the device pins and their corresponding pin type, please refer to the Pin Configuration and Functions section in the SN74HCS14-Q1 data sheet. Thermal Thermal Pad should be tied directly to GND plane to avoid potential failures that can cause excessive current.

GUID-5182B1B1-EC84-44F1-9D51-55FC9B2971DD-low.gifFigure 4-1 Pin Diagram (D, DYY, and PW) Packages
GUID-20201111-CA0I-QBCV-SJQQ-KB4XNSJ2D49H-low.gifFigure 4-2 Pin Diagram (BQA) Package
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
A 1, 3, 5, 9, 11, 13 Input pin is forced to the low logic state. See Device Function Table in the device data sheet for details of how the failure affects functionality. B
GND 7 Normal operation. D
Y 2, 4, 6, 8, 10, 12 Can cause excessive output current; output remains in the low output state independent of input states. A
VCC 14 Device is not powered. System level damage can occur in this scenario. B

Thermal Pad(1)

 — Normal operation. D
(1) BQA package only
Table 4-3 Pin FMA for Device Pins Open-Circuited
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
A 1, 3, 5, 9, 11, 13 Pin is floating, can change output state and cause excessive current from VCC to GND. See Implications of Slow or Floating CMOS Inputs. A
GND 7 Device is not powered. B
Y 2, 4, 6, 8, 10, 12 Normal operation. D
VCC 14 Device is not powered. B

Thermal Pad(1)

 — Normal operation.

D
(1) BQA package only
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Pin Name Pin No. Shorted to Description of Potential Failure Effect(s) Failure Effect Class
A 1, 3, 5, 9, 11, 13 A Two inputs shorted together can cause a loss of functionality or damage to the device. Damage to the device can occur when the input voltage (VI) is driven such that VIL < VI < VIH. A
A 1, 3, 5, 9, 11, 13 Y Can cause loss of functionality or damage to the device. Damage to the device can occur due to feedback oscillation causing excessive current consumption. A
A 1, 3, 5, 9, 11, 13 GND Input pin is forced to the low logic state. See Device Function Table in the device data sheet for details of how the failure affects functionality. B
A 1, 3, 5, 9, 11, 13 Thermal Pad Input pin is forced to the low logic state. See Device Function Table in the device data sheet for details of how the failure affects functionality.

B
A 1, 3, 5, 9, 11, 13 VCC Input pin is forced to the high logic state. See Device Function Table in the device data sheet for details of how the failure affects functionality. B
Y 2, 4, 6, 8, 10, 12 GND Can cause excessive output current; output remains in the low output state independent of input states. A
Y 2, 4, 6, 8, 10, 12 Thermal Pad Can cause excessive output current; output remains in the low output state independent of input states.

A
Y 2, 4, 6, 8, 10, 12 VCC Can cause excessive output current; output remains in the high output state independent of input states. A
Table 4-5 Pin FMA for Device Pins Short-Circuited to VCC
Pin Name Pin No. Description of Potential Failure Effect(s) Failure Effect Class
A 1, 3, 5, 9, 11, 13 Input pin is forced to the high logic state. See Device Function Table in the device data sheet for details of how the failure affects functionality. B
GND 7 Device can not be powered because short is external to device. System level damage can occur in this scenario. B
Y 2, 4, 6, 8, 10, 12 Can cause excessive output current; output remains in the high output state independent of input states. A
VCC 14 Normal operation. D
Thermal Pad(1) — Device is not powered. System level damage can occur in this scenario.

B
(1) BQA package only