SFFSA46 July 2025 TPS2HCS08-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a failure mode analysis (FMA) for the pins of the TPS2HCS08-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. |
The following figures show the TPS2HCS08-Q1 pin diagrams. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the TPS2HCS08-Q1 data sheet.
Figure 4-1 Pin Diagram Version A
Figure 4-2 Pin Diagram Version BFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- Follow the data sheet 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 | Resistor or diode network is bypassed if present. | B |
| SNS | 2 | SNS current diagnostics (including I2T if enabled) are not available. | B |
| VDD | 3 | SPI communication is non-functional. | B |
| DI (version A) | 4 | Output control might be lost in LIMP_HOME state if CHx_LH_IN = 00, otherwise, no effect. | B |
| DI1 (version B) | 4 | Channel 1 is disabled. | B |
| LHI (version A) | 5 | Device is not able to enter in LIMP_HOME state through LHI input. | B |
| DI2 (version B) | 5 | Channel 2 is disabled. | B |
| VOUT1 | 6 | Short to GND protection starts to protect channel 1. | B |
| 7 | |||
| 8 | |||
| VOUT2 | 9 | Short to GND protection starts to protect channel 2. | B |
| 10 | |||
| 11 | |||
| FLT/WAKE_SIG | 12 | Fault indication can be incorrect. Fault indication and LPM wake-up indication cannot be reported to the MCU through the FLT/WAKE_SIG pin. | B |
| SDI | 13 | SPI communication is non-functional. | B |
| SDO | 14 | Cannot use SPI to read faults and diagnostics. Verify that the RVDD resistor is available to limit the short-circuit current. | B |
| CSN | 15 | SPI communication is non-functional. | B |
| SCLK | 16 | SPI communication is non-functional. | 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 | Loss of ground detection
engages and the device turns off channels. Note: Loss of ground detection engages if RSDO ≥ 768Ω. |
B |
| SNS | 2 | SNS current diagnostics (including I2T if enabled) are not available. | B |
| VDD | 3 | SPI communication is non-functional. | B |
| DI (version A) | 4 | Output control might be lost in LIMP_HOME state if CHx_LH_IN = 00, otherwise, no effect. DI is pulled down internally. | B |
| DI1 (version B) | 4 | Channel 1 is disabled. DI1 is pulled down internally. | B |
| LHI (version A) | 5 | Device is not able to enter in LIMP_HOME state through LHI input. LHI is pulled down internally. | B |
| DI2 (version B) | 5 | Channel 2 is disabled. DI2 is pulled down internally. | B |
| VOUT1 | 6 | No effect. If off-state open load detection is configured, open load detection is triggered when channel 1 is disabled. | C |
| 7 | |||
| 8 | |||
| VOUT2 | 9 | No effect. If off-state open load detection is configured, open load detection is triggered when channel 2 is disabled. | C |
| 10 | |||
| 11 | |||
| FLT/WAKE_SIG | 12 | Fault indication can be incorrect. Fault indication and LPM wake-up indication cannot be reported to the MCU through the FLT/WAKE_SIG pin. | B |
| SDI | 13 | SPI communication is non-functional. | B |
| SDO | 14 | Cannot use SPI to read faults and diagnostics. | B |
| CSN | 15 | SPI communication is non-functional. | B |
| SCLK | 16 | SPI communication is non-functional. | 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) | SNS current diagnostic is not available. | B |
| SNS | 2 | 3 (VDD) | Sense output can be incorrect. SPI communication is non-functional. | B |
| VDD | 3 | 4 (DI) | Output control might be lost in LIMP_HOME state if CHx_LH_IN = 00, otherwise, no effect to the output control of the device. SPI communication is non-functional. | B |
| VDD | 3 | 4 (DI1) | Channel 1 output control might be lost. | B |
| DI | 4 | 5 (LHI) | Output control might be lost in LIMP_HOME state if CHx_LH_IN = 00, otherwise, no effect to the output control of the device. Might not be able to enter LIMP_HOME state through the LHI pin. | B |
| DI1 | 4 | 5 (DI2) | Channel 1 or Channel 2 (or both) output control might be lost. | B |
| LHI | 5 | 6 (VOUT1) | Device might not able to enter in LIMP_HOME state through the LHI input. | B |
| DI2 | 5 | 6 (VOUT1) | Channel 2 output control might be lost. | B |
| VOUT2 | 11 | 12 (FLT/WAKE_SIG) | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. Fault indication can be incorrect. Fault indication and LPM wake-up indication cannot be reported to the MCU through the FLT/WAKE_SIG pin. | A |
| FLT/WAKE_SIG | 12 | 13 (SDI) | Fault indication and LPM wake-up indication can be incorrectly reported to the MCU through the FLT/WAKE_SIG pin. SPI communication is non-functional. | B |
| SDI | 13 | 14 (SDO) | SPI communication is non-functional. | B |
| SDO | 14 | 15 (CSN) | SPI communication is non-functional. | B |
| CSN | 15 | 16 (SCLK) | SPI communication is non-functional. | 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 | Supply power is bypassed and the device does not turn on. | B |
| SNS | 2 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |
| VDD | 3 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |
| DI | 4 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |
| DI1 | 4 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |
| LHI | 5 | Device is not able to enter in LIMP_HOME state through the LHI input. | B |
| DI2 | 5 | Channel 2 output control might be lost. | B |
| VOUT1 | 6 | Output shorted to supply. If off-state short-to-battery detection is configured, short-to-battery detection is triggered when channel 1 is disabled. | B |
| 7 | |||
| 8 | |||
| VOUT2 | 9 | Output shorted to supply. If off-state short-to-battery detection is configured, short-to-battery detection is triggered when channel 2 is disabled. | B |
| 10 | |||
| 11 | |||
| FLT/WAKE_SIG | 12 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. Fault indication and LPM wake-up indication can be incorrectly reported to the MCU through the FLT/WAKE_SIG pin. | A |
| SDI | 13 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |
| SDO | 14 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |
| CSN | 15 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |
| SCLK | 16 | If pin voltage exceeds the absolute maximum rating, device damage is possible due to voltage breakdown on the ESD circuit. | A |