ZHCSLM3B August 2020 – May 2024 LP8864-Q1
PRODUCTION DATA
Short LED fault is detected if one or more LED outputs are above the VLEDSHORT typical 5.4V and at least one LED output is inside the normal operation window (see Figure 6-18). Shorted string is disconnected from the boost adaptive control loop and the LED PWM output is disabled. LED_STATUS status bit is set and an interrupt generated similarly as in open LED case. Detailed shorted LED fault can be read from bits SHORT_LED and LEDx_FAULT (x = 1...4), indicating the faulty LED) in LED_FAULT_STATUS register.
In HUD application, when output channels are connected as groups and only one or two groups are active, one more special condition will trigger the short LED fault. This is when boost adaptive voltage comes to minimum and one of the LED channels voltage is still higher than VHEADROOM + VHEADROOM_HYS.