ZHCSG68F MARCH 2017 – JANUARY 2019 TPSM846C23
PRODUCTION DATA.
Table 7 summarizes the various fault protections and associated responses.
NOTE
When configured as parallel operation, the best practice is to have the fault response of the loop master and slave device set as the same to avoid unexpected behavior.
FAULT or WARN | PROGRAMMING | FAULT RESPONSE SETTING | FET BEHAVIOR | ACTIVE DURING TON_RISE | SOURCE OF SMBALERT | SMBALERT MASKABLE | PGOOD |
---|---|---|---|---|---|---|---|
Internal Overtemperature 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 Overtemperature Warn | OT_WARN_LIMIT (51h) | Latch-off or restart on fault | PWM maintains control of FETs | Yes | Yes | Yes | Low |
Ignore fault | High | ||||||
Bandgap Overtemperature 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 | Shutdown | Both FETs off | Yes | Yes | Yes | Low |