SFFSAC9A November 2025 – December 2025 CSD967201-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a failure mode analysis (FMA) for the pins of the CSD967201. 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 (VIN and VDRV, or VCC) (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 shows the CSD967201 pin diagram. For a detailed description of the device pins, see the Pin Configuration and Functions section in the CSD967201 data sheet.
Figure 4-1 Pin Diagram (Top View)Following are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- The VIN and VDRV supplies are within the recommended operating conditions.
- The external components on the pins are within the recommended passive component tolerance.
- The board conditions are within the recommended board level parasitic tolerance.
Table 4-2 Pin FMA for Device Pins Short-Circuited to Ground
| Pin No. | Pin Name | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| 1 | BP33 | The device does not allow PWM switching and remains in tri-state mode. | B |
| 2 | AGND | The device continues to operate, but the AGND pin potentially experiences more disturbance to the transient ground. The PWM and interface parametrical are potentially skewed. | C |
| 3 | VCC | The device remains in a POR state. The device does not power on and remains in reset. | B |
| 4 | VDRV | The device remains in a POR state. The device does not power on and remains in reset. | B |
| 5-10 | PGND | The device operates as normal with full functionality. | D |
| 19-22 | |||
| 35 | |||
| 37 | |||
| 11-18 | SW | The device is not functional and the power stage is not able to control VOUT. The peak current limit is used to limit the current of the high-side FET. The SW pin to ground causes the system regulation to drop to 0V. If there is a hard 0Ω short, there is potential damage to the internal high-side FET. | A |
| 23 | |||
| 38 | |||
| 24-29 | VIN | The device does not allow the power stage or IMON to function, and the device remains in a non-switching mode. | B |
| 30 | PHASE | The device is not functional and the power stage is not able to control VOUT. The peak current limit is used to limit the current of the high-side FET. The SW pin to ground causes the system regulation to drop to 0V. If there is a hard 0Ω short, there is potential damage to the internal high-side FET. | A |
| 31 | BOOT | The boot cap cannot charge, and the device does not have a floating supply for the boot domain. The boot UV detection does not allow the high-side FET to turn on, potentially causing a loss of regulation in the system. | B |
| 32 | PWM | There is a loss of functionality, with the low-side FET staying on after start-up. | B |
| 33 | EN | The device does not allow for PWM switching. | A |
| 34 | TMON/FLT | There is excessive current on the VDRV pin, with no TMON signal for all power stages in the system. | B |
| 36 | IMON | The controller sources large current from CSBIAS across the internal or external 1kΩ resistor in the system. Faults potentially do not trigger correctly. | A |
Table 4-3 Pin FMA for Device Pins Open-Circuited
| Pin No. | Pin Name | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| 1 | BP33 | If no cap is connected, the LDO is unstable. The PWM is potentially falsely detected, and TMON potentially experiences small oscillations. | C |
| 2 | AGND | The device does not interpret the PWM signal correctly and potentially does not turn on. | C |
| 3 | VCC | The device remains in a POR state. The device does not power on and remains in reset. | B |
| 4 | VDRV | The device remains in a POR state. The device does not power on and remains in reset. | B |
| 5-10 | PGND | GND is still present due to multiple PGND pins. The full functionality of the device is maintained. | D |
| 19-22 | |||
| 35 | |||
| 37 | |||
| 11-18 | SW | The device is not functional and output regulation cannot be controlled by the power stage. | B |
| 23 | |||
| 38 | |||
| 24-29 | VIN | The device does not allow the power stage or IMON to function, and the device remains in a non-switching mode. | B |
| 30 | PHASE | The device is not functional, and output regulation cannot be controlled by the power stage. | B |
| 31 | BOOT | The boot cap cannot charge, and the device does not have a floating supply for the boot domain. The boot UV detection does not allow the high-side FET to turn on, potentially causing a loss of regulation in the system. | B |
| 32 | PWM | The device detects this pin as a PWM tri-state input and both the low-side and high-side FETs remain off. | B |
| 33 | EN | The device pulls down internally and does not allow the PWM input to turn the power stage on or off. | B |
| 34 | TMON/FLT | The TMON output does not report for the power stage. | B |
| 36 | IMON | The controller sources large current from CSBIAS across the internal or external 1kΩ resistor in the system. Faults potentially do not trigger correctly. | A |
Table 4-4 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
| Pin No. | Pin Name | Shorted to | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|---|
| 1 | BP33 | IMON | Depending on the strength of the IMON drive, the BP33 pin is likely to dominate. The BP33 pin potentially rises to VCC. | B |
| AGND | The device does not allow PWM switching and remains in tri-state mode. | B | ||
| 2 | AGND | BP33 | The device does not allow PWM switching and remains in tri-state mode. | B |
| VCC | The device remains in a POR state. The device does not power on and remains in reset. | B | ||
| 3 | VCC | AGND | The device remains in a POR state. The device does not power on and remains in reset. | B |
| VDRV | The device functions. There is no filter between the VCC and VDRV pins. The system potentially has more jitter. | C | ||
| 4 | VDRV | VCC | The device functions. There is no filter between the VCC and VDRV pins. The system potentially has more jitter. | C |
| PGND | The device remains in a POR state. The device does not power on and remains in reset. | B | ||
| 5-10 | PGND | VDRV | The device remains in a POR state. The device does not power on and remains in reset. | B |
| 19-22 | IMON | The controller sources large current from CSBIAS across the internal or external 1kΩ resistor in the system. Faults potentially do not trigger correctly. | A | |
| 35 | TMON/FLT | There is excessive current on the VDRV pin, with no TMON signal for all power stages in the system. | B | |
| 37 | VIN | The device does not allow the power stage or IMON to function, and the device remains in a non-switching mode. | B | |
| SW | The device is not functional and the power stage is not able to control VOUT. The peak current limit is used to limit the current of the high-side FET. The SW pin to ground causes the system regulation to drop to 0V. If there is a hard 0Ω short, there is potential damage to the internal high-side FET. | A | ||
| 11-18 | SW | PGND | The device is not functional and the power stage is not able to control VOUT. The peak current limit is used to limit the current of the high-side FET. The SW pin to ground causes the system regulation to drop to 0V. If there is a hard 0Ω short, there is potential damage to the internal high-side FET. | A |
| 23 | ||||
| 38 | VIN | This is equivalent to a high-side FET short. The high-side short protection turns on the low-side FET and potentially damages the FET. | A | |
| 24-29 | VIN | SW | This is equivalent to a high-side FET short. The high-side short protection turns on the low-side FET and potentially damages the FET. | A |
| PHASE | This is equivalent to a high-side FET short. The high-side short protection turns on the low-side FET and potentially damages the FET. | A | ||
| 30 | PHASE | VIN | This is equivalent to a high-side FET short. The high-side short protection turns on the low-side FET and potentially damages the FET. | A |
| BOOT | The boot cap does not have a floating supply for the boot domain. The boot UV detection does not allow the high-side FET to turn on, potentially causing a loss of regulation in the system. | B | ||
| 31 | BOOT | PHASE | The boot cap does not have a floating supply for the boot domain. The boot UV detection does not allow the high-side FET to turn on, potentially causing a loss of regulation in the system. | B |
| PWM | The boot cap does not have a floating supply for the boot domain. The boot UV detection does not allow the high-side FET to turn on, potentially causing a loss of regulation in the system. If the BOOT pin is higher than the VCC supply, damage can occur to the PWM input. | B | ||
| 32 | PWM | BOOT | The boot cap does not have a floating supply for the boot domain. The boot UV detection does not allow the high-side FET to turn on, potentially causing a loss of regulation in the system. If the BOOT pin is higher than the VCC supply, damage can occur to the PWM input. | B |
| EN | If EN = VCC, the high-side FET remains on. | B | ||
| 33 | EN | PWM | If EN = VCC, the high-side FET remains on. | B |
| TMON/FLT | There is a loss of TMON and FAULT detection. TMON does not function. | B | ||
| 34 | TMON/FLT | EN | There is a loss of TMON and FAULT detection. TMON does not function. | B |
| VIN | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A | ||
| 36 | IMON | VIN | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A |
| BP33 | The controller sinks large current from the BP33 pin across the internal or external 1kΩ resistor in the system. Faults potentially do not trigger correctly. | A |
Table 4-5 Pin FMA for Device Pins Short-Circuited to VIN
| Pin No. | Pin Name | Description of Potential Failure Effects | Failure Effect Class |
|---|---|---|---|
| 1 | BP33 | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A |
| 2 | AGND | The power supply is missing. The device does not power up, with a large uncontrolled VIN input current, which potentially causes damage to the device. | A |
| 3 | VCC | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A |
| 4 | VDRV | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A |
| 5-10 | PGND | The power supply is missing. The device does not power up, with a large uncontrolled VIN input current, which potentially causes damage to the device. | A |
| 19-22 | |||
| 35 | |||
| 37 | |||
| 11-18 | SW | There is potential damage to the low-side FET. The high-side short detection forces the low-side FET to turn on if EN = 1. | A |
| 23 | |||
| 38 | |||
| 30 | PHASE | There is potential damage to the low-side FET. The high-side short detection forces the low-side FET to turn on if EN = 1. | A |
| 31 | BOOT | There is potential damage to the low-side FET. The high-side short detection forces the low-side FET to turn on if EN = 1. | A |
| 32 | PWM | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A |
| 33 | EN | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A |
| 34 | TMON/FLT | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. | A |
| 36 | IMON | There is damage to the internal, 5V-rated circuitry. If VIN > 8V, there is potential damage to the device. Faults potentially do not trigger correctly. | A |