SFFS044A January 2021 – July 2026 TPS2HB16-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a failure mode analysis (FMA) for the pins of the TPS2HB16-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
| Class | Failure Effects |
|---|---|
| A | Potential device damage that affects functionality. |
| B | No device damage, but loss of functionality. |
| C | No device damage, but performance degradation. |
| D | No device damage, no impact to functionality or performance. |
Figure 4-1 and Figure 4-2 shows the TPS2HB16-Q1 pin diagrams. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS2HB16-Q1 datasheet.
Figure 4-1 Pin Diagram Version A and B
Figure 4-2 Pin Diagram Version FFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- Follow the datasheet recommendations for operating conditions, external component selection, and PCB layout
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| GND | 1 | The resistor or diode network is bypassed if present. | B |
| SNS | 2 | The SNS current diagnostic is not available. | B |
| LATCH | 3 | The device operates as normal with the device in automatic retry mode. | B |
| EN1 | 4 | The device operates as normal with channel 1 output off (FET turned off). | B |
| ILIM1 | 5 | The current limit for channel 1 defaults to the internal limit. | C |
| FLT1 | 5 | For Version F only: The open drain fault diagnostics of channel 1 cannot be reported. | B |
| VOUT1 | 6, 7, 8 | Short to GND protection engages to protect the device. | B |
| VOUT2 | 9, 10, 11 | Short to GND protection engages to protect the device. | B |
| ILIM2 | 12 | The current limit for channel 2 defaults to the internal limit. | C |
| FLT2 | 12 | For Version F only: The open drain fault diagnostics of channel 2 cannot be reported. | B |
| EN2 | 13 | The device operates as normal with the channel 2 output off (FET turned off). | B |
| SEL1 | 14 | The device operates as normal with diagnostics corresponding to SEL1 = LOW. | B |
| SEL2 | 15 | The device operates as normal with diagnostics corresponding to SEL2 = LOW. | B |
| DIAG_EN | 16 | The device operates as normal with the diagnostics function disabled. | B |
Table 4-3 Pin FMA for Device Pins Open-Circuited
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| GND | 1 | The output is off with the FET turned off. | B |
| SNS | 2 | The SNS current diagnostic is not available. | B |
| LATCH | 3 | The device operates as normal with the device in automatic retry mode. The internal pulldown resistor pull the pin to GND. | B |
| EN1 | 4 | The device operates as normal with the channel 1 output off (FET turned off). The internal pulldown resistor pull the pin to GND. | B |
| ILIM1 | 5 | The current limit for channel 1 defaults to the internal limit. | C |
| FLT1 | 5 | For Version F only: The open drain fault diagnostics of channel 1 cannot be reported. | B |
| VOUT1 | 6, 7, 8 | The channel 1 output is off. Open load detection is triggered in off-state while in the diagnostics state. | B |
| VOUT2 | 9, 10, 11 | The channel 2 output is off. Open load detection is triggered in off-state while in the diagnostics state. | |
| ILIM2 | 12 | The current limit for channel 2 defaults to the internal limit. | C |
| FLT2 | 12 | For Version F only: The open drain fault diagnostics of channel 2 cannot be reported. | B |
| EN2 | 13 | The device operates as normal with the channel 2 output off (FET turned off). The internal pulldown resistor pulls the pin to GND. | B |
| SEL1 | 14 | The device operates as normal with diagnostics corresponding to SEL1 = LOW. The internal pulldown resistor pulls the pin to GND. | B |
| SEL2 | 15 | The device operates as normal with diagnostics corresponding to SEL2 = LOW. The internal pulldown resistor pulls the pin to GND. | B |
| DIAG_EN | 16 | The device operates as normal with the diagnostics function disabled. The internal pulldown resistor pulls the pin to GND. | B |
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
| Pin Name | Pin No. | Shorted to | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|---|
| GND | 1 | 2 (SNS) | The SNS current diagnostic is not available. | B |
| SNS | 2 | 3 (LATCH) | The behavior of the device is undefined, and depends on the voltage of the pin. The sense output is potentially incorrect. The latch function is potentially enabled if the pin voltage > VIH. The latch function is potentially disabled if the pin voltage < VIL. | B |
| LATCH | 3 | 4 (EN) | The behavior of the device depends on the voltage of the pin. The latch function is potentially enabled if the pin voltage > VIH. The latch function is potentially disabled if the pin voltage < VIL. | B |
| EN1 | 4 | 5 (ILIM1) | The behavior of the device is undefined. The channel is potentially enabled if the pin voltage > VIH. The channel is potentially disabled if the pin voltage < VIL. The current limit threshold of channel 1 is incorrect. | B |
| EN1 | 4 | 5 (FLT1) | For Version F only: The behavior of the device is undefined. The channel is potentially enabled if the pin voltage > VIH. The channel is potentially disabled if the pin voltage < VIL. The open drain fault diagnostics of channel 1 cannot be reported. | B |
| ILIM1 | 5 | 6 (VOUT1) | The behavior of the device is undefined. The current limit threshold (channel 1) is not correct or short circuit or overload protection potentially does not function. The VOUT behavior of channel 1 is potentially incorrect. | B |
| FLT1 | 5 | 6 (VOUT1) | For Version F only: The open drain fault diagnostics of channel 1 cannot be reported. The VOUT behavior of channel 1 is potentially incorrect. | B |
| VOUT1 | 6, 7, 8 | 5 (ILIM1) | The behavior of the device is undefined. The current limit threshold (channel 1) is not correct or short circuit or overload protection potentially does not function. The VOUT behavior of channel 1 is potentially incorrect. | A |
| VOUT1 | 6, 7, 8 | 5 (FLT1) | For Version F only: The open drain fault diagnostics of channel 1 cannot be reported. The VOUT behavior of channel 1 is potentially incorrect. | B |
| VOUT2 | 9, 10, 11 | 12 (ILIM2) | The behavior of the device is undefined. The current limit threshold (channel 2) is not correct or short circuit or overload protection potentially does not function. The VOUT behavior of channel 2 is potentially incorrect. | A |
| VOUT2 | 9, 10, 11 | 12 (FLT2) | For Version F only: The behavior of the device is undefined. The open drain fault diagnostics of channel 1 cannot be reported. The VOUT behavior of channel 2 is potentially incorrect. | B |
| ILIM2 | 12 | 13 (EN2) | The behavior of the device is undefined. The channel is potentially enabled if the pin voltage > VIH. The channel is potentially disabled if the pin voltage < VIL. The current limit threshold of channel 2 is incorrect. | B |
| FLT2 | 12 | 13 (EN2) | For Version F only: The behavior of the device is undefined. The channel is potentially enabled if the pin voltage > VIH. The channel is potentially disabled if the pin voltage < VIL. The open drain fault diagnostics of channel 1 cannot be reported. | B |
| EN2 | 13 | 14 (SEL1) | The behavior of the device is undefined. Channel 2 is potentially enabled if the pin voltage > VIH. Channel 2 is potentially disabled if the pin voltage < VIL. | B |
| SEL1 | 14 | 15 (SEL2) | The behavior of the device depends on the voltage of the adjacent pin affecting the diagnostic output. | B |
| SEL2 | 15 | 16 (DIAG_EN) | The behavior of the device depends on the voltage of the adjacent pin affecting the diagnostic output. The diagnostic function is potentially enabled if the pin voltage > VIH. The diagnostic function is potentially disabled if the pin voltage < VIL. | B |
| DIAG_EN | 16 | 15 (SEL2) | The behavior of the device depends on the voltage of the adjacent pin affecting the diagnostic output. The diagnostic function is potentially enabled if the pin voltage > VIH. The diagnostic function is potentially disabled if the pin voltage < VIL. | B |
Table 4-5 Pin FMA for Device Pins Short-Circuited to
Supply
| Pin Name | Pin No. | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| GND | 1 | The supply power is bypassed, and the device does not turn on. | B |
| SNS | 2 | The behavior of the device is undefined; and potentially causes damage to the device due to voltage breakdown on the ESD circuit. | A |
| LATCH | 3 | If the voltage of the pin exceeds the voltage range for the pin in the datasheet, the exceedance potentially causes damage to the device due to voltage breakdown on the ESD circuit. The behavior of the device depends on the supply voltage. | A |
| EN1 | 4 | The behavior of the device is undefined. If the voltage of the pin exceeds the voltage range for the pin in the datasheet, the exceedance potentially causes damage to the device due to voltage breakdown on the ESD circuit. | A |
| ILIM1 | 5 | The device operates as normal, but with channel 1 higher current limit is programmed with an internal reference. There is no damage to the device. | C |
| FLT1 | 5 | For Version F only: The open drain fault diagnostics of channel 1 cannot be reported. | B |
| VOUT | 6, 7, 8, 9, 10, 11 | Output 1 is stuck on to supply. Open load detection is triggered in off-state in the diagnostics state. | C |
| VOUT2 | 9, 10, 11 | Output 2 is stuck on to supply. Open load detection is triggered in off-state in the diagnostics state. | C |
| ILIM2 | 12 | The device operates as normal, but with channel 2 higher current limit is programmed with an internal reference. | C |
| FLT2 | 12 | For Version F only: The open drain fault diagnostics of channel 2 cannot be reported. | B |
| EN2 | 13 | The behavior of the device is undefined. If the voltage of the pin exceeds the voltage range for the pin in the datasheet, the exceedance potentially causes damage to the device due to voltage breakdown on the ESD circuit. | A |
| SEL1 | 14 | The behavior of the device is undefined. If the voltage of the pin exceeds the voltage range for the pin in the datasheet, the exceedance potentially causes damage to the device due to voltage breakdown on the ESD circuit. | A |
| SEL2 | 15 | The behavior of the device is undefined. If the voltage of the pin exceeds the voltage range for the pin in the datasheet, the exceedance potentially causes damage to the device due to voltage breakdown on the ESD circuit. | A |
| DIAG_EN | 16 | The behavior of the device is undefined. If the voltage of the pin exceeds the voltage range for the pin in the datasheet, the exceedance potentially causes damage to the device due to voltage breakdown on the ESD circuit. | A |