SFFS059 January   2023 DRV8145-Q1

 

  1.   Trademarks
  2. 1Overview
  3. 2Functional Safety Failure In Time (FIT) Rates
  4. 3Failure Mode Distribution (FMD)
  5. 4Pin Failure Mode Analysis (Pin FMA)
    1. 4.1 SPI "P" variant in HTSSOP package
    2. 4.2 SPI "S" variant in VQFN-HR package
    3. 4.3 HW variant in VQFN-HR package

4.2 SPI "S" variant in VQFN-HR package

Figure 4-3shows the pin diagram. For a detailed description of the device pins please refer to the Pin Configuration and Functions section in the DRV8145-Q1 data sheet.

GUID-20200902-CA0I-SGRG-MRKV-ZX9P0ZGFXWMV-low.gif Figure 4-3 SPI "S" variant
Table 4-6 Pin FMA for Device Pins Short-Circuited to Ground
Pin Description of Potential Failure Effect(s) Failure Effect Class
No. Name
1 nFAULT False fault signaling possible. Device will continue to operate as commanded. B
2 IPROPI IPROPI feedback is lost. ITRIP regulation, if enabled, is also lost. B
3 nSLEEP Device will be in SLEEP state and OUT is Hi-Z B
4 VM Device is powered off with driver Hi-Z. B
5, 6 OUT If OUT is commanded to be pulled high, short is detected and OUT is Hi-Z. B
7 GND Normal function. D
8,9 OUT If OUT is commanded to be pulled high, short is detected and OUT is Hi-Z. B
10 VCP Device damage possible. Device behavior can not be guaranteed. A
11 DRVOFF Pin based shutoff function is lost. B
12 IN External PWM control is lost. Internal ITRIP regulation is ok. No risk of spin direction reversal. B
13 nSCS SPI communication is lost. B
14 SCLK SPI communication is lost. B
15 SDI SPI communication is lost. B
16 SDO SPI communication is lost. B
Table 4-7 Pin FMA for Device Pins Open-Circuited
Pin Description of Potential Failure Effect(s) Failure Effect Class
No. Name
1 nFAULT False fault signaling possible. Device will continue to operate as commanded. B
2 IPROPI IPROPI feedback is lost. Load will be forced to recirculate if ITRIP regulation is enabled. B
3 nSLEEP Device will be in SLEEP state and OUT is Hi-Z. B
4 VM Device is powered off with driver Hi-Z. B
5, 6 OUT Load drive capability is lost. B
7 GND Normal function. D
8,9 OUT Load drive capability is lost. B
10 VCP The driver can't keep up with PWM frequency > 20 KHz B
11 DRVOFF Pin based shutoff is triggered and OUT is Hi-Z B
12 IN External PWM control is lost. Internal ITRIP regulation is OK. No risk of spin direction reversal. B
13 nSCS SPI communication is lost. B
14 SCLK SPI communication is lost. B
15 SDI SPI communication is lost. B
16 SDO SPI communication is lost. B
Table 4-8 Pin FMA for Device Pins Short-Circuited to Adjacent Pin
Short between pins Description of Potential Failure Effect(s) Failure Effect Class
nFAULT SDO False fault signaling possible. SPI communication will be affected during fault assertion. B
IPROPI nFAULT False fault signaling possible. IPROPI feedback is inaccurate. ITRIP regulation levels, if enabled, will be lower. B
nSLEEP IPROPI ITRIP regulation levels, if enabled, will be lower. B
VM nSLEEP SLEEP functionality is lost. B
OUT VM If OUT is commanded to be pulled low, short is detected and OUT is Hi-Z. B
GND OUT If OUT is commanded to be pulled high, short is detected and OUT is Hi-Z. B
VCP VM Pull up path RON (High-side FET) will be much higher. B
DRVOFF VCP Device damage possible. Device behavior can not be guaranteed. A
IN DRVOFF Either OUT is Hi-Z or external PWM control is lost. Internal ITRIP regulation is ok. No risk of spin direction reversal. B
nSCS IN SPI communication is affected. External PWM control is lost. Internal ITRIP regulation is OK. No risk of spin direction reversal. B
SCLK nSCS SPI communication is lost. B
SDI SCLK SPI communication is lost. B
SDO SDI SPI communication is lost. B
Table 4-9 Pin FMA for Device Pins Short-Circuited to VM
Pin Description of Potential Failure Effect(s) Failure Effect Class
No. Name
1 nFAULT Device damage possible. A
2 IPROPI Device damage possible. A
3 nSLEEP SLEEP functionality is lost. B
4 VM Device is powered off with driver Hi-Z. B
5, 6 OUT If OUT is commanded to be pulled low, short is detected and OUT is Hi-Z. B
7 GND Normal function. D
8,9 OUT If OUT is commanded to be pulled low, short is detected and OUT is Hi-Z. B
10 VCP Pull up path RON (High-side FET) will be much higher. B
11 DRVOFF OUT is Hi-Z. B
12 IN Device damage possible. A
13 nSCS Device damage possible. A
14 SCLK Device damage possible. A
15 SDI Device damage possible. A
16 SDO Device damage possible. A