The TPS92633-Q1 device has LED short-to-GND detection. The LED short-to-GND detection monitors the output voltage when the output current is enabled. Once a short-to-GND LED failure is detected, the device turns off the faulty channel and retries automatically, regardless of the state of the PWM input. When the retry mechanism detects the removal of the LED short-to-GND fault, the device resumes to normal operation.

The TPS92633-Q1 monitors the V_(OUTx) voltage and V_(RESx) voltage of each channel and compares it with the internal reference voltage to detect a short-to-GND failure. When V_(OUTx) or V_(RESx) voltage falls below V_{(SG_th_falling)} longer than the deglitch time of t_{(SG_deg)}, the device asserts the short-to-GND fault and pulls low the FAULT pin. During the deglitch time period, if V_(OUTx) and V_(RESx) rises above V_{(SG_th_rising)}, the timer is reset.

Once the TPS92633-Q1 has asserted a short-to-GND fault, the device turns off the faulty output channel and retries automatically with a small current. During retrying the device sources a small current I_(Retry) from SUPPLY to OUT to pull up the LED loads continuously. Once auto-retry detects output voltage rising above V_{(SG_th_rising)}, it clears the short-to-GND fault and resumes to normal operation. Figure 7-7 illustrates the timing for LED short-circuit detection, protection, retry and recovery.

Figure 7-7 LED Short-to-GND Detection and Recovery Timing Diagram

The detailed information and value of each time period in Figure 7-7 is described in Timing Requirements.