JAJSEE1B January 2018 – January 2020 TPS92611-Q1
PRODUCTION DATA.
The TPS92611-Q1 device has LED short-to-GND detection. Short-to-GND detection monitors the output voltage when the channel is in the ON state. Once a short-to-GND LED failure is detected, the device turns off the output channel and retries automatically, ignoring the PWM input. If the retry mechanism detects removal of the LED short-to-GND fault, the device resumes normal operation.
The device monitors the V(OUT) voltage and compares it with the internal reference voltage to detect a short-to-GND failure. If V(OUT) falls below V(SG_th_rising) longer than the deglitch time of t(SG_deg), the device asserts the short-to-GND fault and pulls FAULT low. During the deglitching time period, if V(OUT) rises above V(SG_th_falling), the timer is reset.
Once the device has detected a short-to-GND fault, the device turns off the output channel and retries automatically with a small current. When retrying, the device sources a small current I(retry) from IN to OUT to pull up the LED loads continuously. Once auto-retry detects output voltage rising above V(SG_th_falling), it clears the short-to-GND fault and resumes normal operation.