SFFS114 March 2021 DRV8899-Q1
4 Pin Failure Mode Analysis (Pin FMA)
This section provides a Failure Mode Analysis (FMA) for the pins of the DRV8899-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.
| 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 package pin diagram. For a detailed description of the device pins please refer to the 'Pin Configuration and Functions' section in the datasheet.
Figure 4-1 Pin DiagramFollowing are the assumptions of use and the device configuration assumed for the pin FMA in this section:
- The device is used with external components consistent with the values described in the external component table of the datasheet.
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
VM | 1 | Device will not power up | B |
PGND | 2 | Intended Operation | D |
AOUT1 | 3 | Device will signal OCP fault | B |
AOUT2 | 4 | Device will signal OCP fault | B |
BOUT2 | 5 | Device will signal OCP fault | B |
BOUT1 | 6 | Device will signal OCP fault | B |
PGND | 7 | Intended Operation | D |
VM | 8 | Device will signal OCP fault | B |
GND | 9 | Intended Operation | D |
DVDD | 10 | Device external digital power supply stuck low. Device non-operational. | B |
nFAULT | 11 | Device will always be signaling fault | B |
VREF | 12 | Current regulation will be lost | B |
nSCS | 13 | SPI read write functions will be non-functional | B |
VSDO | 14 | SPI read function will be non-functional | B |
SDO | 15 | SPI read function will be non-functional | B |
SDI | 16 | SPI read write functions will be non-functional | B |
SCLK | 17 | SPI read write functions will be non-functional | B |
STEP | 18 | STEP input capability will be lost | B |
DIR | 19 | Direction change capability will be lost | B |
DRVOFF | 20 | Driver control will be lost | B |
nSLEEP | 21 | Device will be in sleep state with OUTx Hi-Z | B |
CPL | 22 | Device charge pump non-operational. Device CPUV fault. | A |
CPH | 23 | Device charge pump non-operational. Device CPUV fault. | A |
VCP | 24 | Device charge pump non-operational. Device CPUV fault. | A |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
VM | 1 | Device will not power up | B |
PGND | 2 | Device will not power up | B |
AOUT1 | 3 | Device will not be able to drive the load properly | B |
AOUT2 | 4 | Device will not be able to drive the load properly | B |
BOUT2 | 5 | Device will not be able to drive the load properly | B |
BOUT1 | 6 | Device will not be able to drive the load properly | B |
PGND | 7 | Device will not power up | B |
VM | 8 | Device will not power up | B |
GND | 9 | Device will not power up | B |
DVDD | 10 | Device external digital power supply missing. Device non-operational. | B |
nFAULT | 11 | Fault signaling will be lost | B |
VREF | 12 | Current regulation will be lost | B |
nSCS | 13 | SPI read write functions will be non-functional | B |
VSDO | 14 | SPI read function will be non-functional | B |
SDO | 15 | SPI read function will be non-functional | B |
SDI | 16 | SPI read write functions will be non-functional | B |
SCLK | 17 | SPI read write functions will be non-functional | B |
STEP | 18 | Driver control will be lost | B |
DIR | 19 | Driver control will be lost | B |
DRVOFF | 20 | Driver control will be lost | B |
nSLEEP | 21 | Device will be in sleep state | B |
CPL | 22 | Device charge pump non-operational. Device CPUV fault. | B |
CPH | 23 | Device charge pump non-operational. Device CPUV fault. | B |
VCP | 24 | Device charge pump non-operational. Device CPUV fault. | B |
| Pin Name | Pin No. | Shorted to Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|---|
VM | 1 | 2 | Device will not power up | B |
PGND | 2 | 3 | Device will signal OCP fault | B |
AOUT1 | 3 | 4 | Device will signal OCP fault | B |
AOUT2 | 4 | 5 | Device will signal OCP fault | B |
BOUT2 | 5 | 6 | Device will signal OCP fault | B |
BOUT1 | 6 | 7 | Device will signal OCP fault | B |
PGND | 7 | 8 | Device will not power up | B |
VM | 8 | 9 | Device will not power up | B |
GND | 9 | 10 | Device external digital power supply stuck low. Device non-operational. | B |
DVDD | 10 | 11 | Device will reset whenever nFAULT is asserted low | B |
nFAULT | 11 | 12 | Current regulation and fault signalling will be lost | B |
VREF | 12 | 13 | Current regulation and SPI read write functions will be non-functional | B |
nSCS | 13 | 14 | SPI read write functions will be non-functional | B |
VSDO | 14 | 15 | SPI read write functions will be non-functional | B |
SDO | 15 | 16 | SPI read write functions will be non-functional | B |
SDI | 16 | 17 | SPI read write functions will be non-functional | B |
SCLK | 17 | 18 | SPI read write functions and GPIO step input will be non-functional | B |
STEP | 18 | 19 | STEP input and direction change capabilities will be lost | B |
DIR | 19 | 20 | Direction change and OUTx control will be lost | B |
DRVOFF | 20 | 21 | Driver control will be lost | B |
nSLEEP | 21 | 22 | Device charge pump non-operational. Device CPUV fault. | A |
CPL | 22 | 23 | Device charge pump non-operational. Device CPUV fault. | A |
CPH | 23 | 24 | Device charge pump non-operational. Device CPUV fault. | A |
VCP | 24 | 1 | Device charge pump non-operational. Device CPUV fault. | B |
| Pin Name | Pin No. | Description of Potential Failure Effect(s) | Failure Effect Class |
|---|---|---|---|
VM | 1 | Intended Operation | D |
PGND | 2 | Device will not power up | B |
AOUT1 | 3 | Device will signal OCP fault | B |
'AOUT2 | 4 | Device will signal OCP fault | B |
BOUT2 | 5 | Device will signal OCP fault | B |
BOUT1 | 6 | Device will signal OCP fault | B |
PGND | 7 | Device will not power up | B |
VM | 8 | Intended Operation | D |
GND | 9 | Device will not power up | B |
DVDD | 10 | Low voltage pin max voltage violated. | A |
nFAULT | 11 | Low voltage pin max voltage violated. | A |
VREF | 12 | Low voltage pin max voltage violated. | A |
nSCS | 13 | Low voltage pin max voltage violated. | A |
VSDO | 14 | Low voltage pin max voltage violated. | A |
SDO | 15 | Low voltage pin max voltage violated. | A |
SDI | 16 | Low voltage pin max voltage violated. | A |
SCLK | 17 | Low voltage pin max voltage violated. | A |
STEP | 18 | Low voltage pin max voltage violated. | A |
DIR | 19 | Low voltage pin max voltage violated. | A |
DRVOFF | 20 | Low voltage pin max voltage violated. | A |
nSLEEP | 21 | Driver control will be lost | B |
CPL | 22 | Device charge pump non-operational. Device CPUV fault. | A |
CPH | 23 | Device charge pump non-operational. Device CPUV fault. | A |
VCP | 24 | Device charge pump non-operational. Device CPUV fault. | B |