SLUSCC7C July 2016 – June 2018 TPS546C23
PRODUCTION DATA.
Table 2 summarizes the various fault protections and associated responses.
FAULT or WARN | PROGRAMMING | FAULT RESPONSE SETTING | FET BEHAVIOR | ACTIVE DURING TON_RISE | SOURCE OF SMBALERT | SMBALERT MASKABLE | PGOOD |
---|---|---|---|---|---|---|---|
Internal Over Temp Fault | OT_FAULT_LIMIT (4Fh) | Latch-off | Both FETs off | Yes | Yes | Yes | Low |
Restart | Both FETs off, then restart after cooling down(1) | Low | |||||
Ignore | FETs still controlled by PWM | High | |||||
Internal Over Temp Warn | OT_WARN_LIMIT (51h) | Latch-off or Restart on Fault | PWM maintains control of FETs | Yes | Yes | Yes | Low |
Ignore Fault | High | ||||||
Bandgap Over Temp Fault | Threshold fixed internally | Latch-off | Both FETs off | Yes | Yes | Yes | Low |
Restart | Both FETs off, then restart after cooling down(1) | ||||||
Ignore | Both FETs off, then restart after cooling down(2) | ||||||
Low-Side OC Fault | IOUT_OC_FAULT_LIMIT (46h) | Latch-off | 3 PWM counts, then both FETs off | Yes | Yes | Yes | Low |
Restart | 3 PWM counts, then both FETs off, restart after 7×TON_RISE | Low | |||||
Ignore | FETs still controlled by PWM | High | |||||
Low-Side OC Warn | IOUT_OC_WARN_LIMIT | Latch-off or Restart on Fault | PWM maintains control of FETs | Yes | Yes | Yes | Low |
Ignore Fault | High | ||||||
High-Side OC Fault | Latch-off | 3 PWM counts, then both FETs off | Yes | Yes | Yes | Low | |
Restart | 3 PWM counts, then both FETs off, restart after 7 × TON_RISE | Low | |||||
Ignore | Cycle-by-cycle peak current limit | High | |||||
VOUT OV Fault | PCT_OV_UV_WRN_FLT_LIMITS (MFR_SPECIFIC_07) (D7h) | Latch-off | High-side FET OFF, low-side FET response configured byOV_RESP_SEL Bit: latch ON or turn on till FB drops below 0.2 V | Yes | Yes | Yes | Low |
Restart | High-side FET OFF, low-side FET response configured byOV_RESP_SEL Bit: latch ON or turn on till FB drops below 0.2 V. Then restart after 7 × TON_RISE | ||||||
Ignore | PWM maintains control of FETs | ||||||
VOUT OV Warn | PCT_OV_UV_WRN_FLT_LIMITS (MFR_SPECIFIC_07) (D7h) | Latch-off or Restart on Fault | PWM maintains control of FETs | Yes | Yes | Yes | Low |
Ignore Fault | |||||||
VOUT UV Fault | PCT_OV_UV_WRN_FLT_LIMITS (MFR_SPECIFIC_07) (D7h) | Latch-off | Both FETs off | No | Yes | Yes | Low |
Restart | Both FETs off, then restart after 7×TON_RISE | ||||||
Ignore | PWM maintains control of FETs | ||||||
VOUT UV Warn | PCT_OV_UV_WRN_FLT_LIMITS (MFR_SPECIFIC_07) (D7h) | Latch-off or Restart on Fault | PWM maintains control of FETs | No | Yes | Yes | Low |
Ignore Fault | |||||||
TON Max Fault | TON_MAX_FAULT_LIMIT | Latch-off | Both FETs off | No | Yes | Yes | Low |
Restart | Both FETs off, then restart after 7×TON_RISE | ||||||
Ignore | PWM maintains control of FETs | ||||||
VIN UVLO | VIN_ON, VIN_OFF | Shut down | Both FETs off | Yes | Yes | Yes | Low |
NOTE
The best practice is to have the fault response of the loop master and slave device set as the same to avoid unexpected behavior.