TPS92682-Q1 include various fault handling and diagnostic features. Figure 4-7 and Figure 4-8 show the LED short and LED open protection for CC SEPIC channel.

As shown in Figure 4-7, when a short across the LED load occurs, Under Voltage protection is triggered (if UV Fault is enabled), the COMP-pin is pulled low, and the associated channel is turned off. The channel remains off for the programmed main fault timer (MFT). When the MFT count completes, channel performs a soft-start sequence. The CC SEPIC can regulate the output current into an output short. If there is a continuous short on the output, UV fault is triggered, when the soft-start ramp completes. UV is disabled during soft-start ramp. If the output short is removed, the controller continues regulating current into the LEDs on the output. In the test in Figure 4-7, output PFET is removed.

As shown in Figure 4-8, when open LED load occurs, the load voltage increases above the programmed overvoltage (OV) threshold, and the associated channel turns off. The channel remains off until the load voltage drops below a OV hysteresis value, when the channel performs a soft-start sequence. Set the OV threshold by programming the OV register and the adjusting the resistor divider connected to the FB2/OV2 pin.

Figure 4-7 CC SEPIC LED Output Short

Figure 4-8 CC SEPIC LED Open and Over-Voltage Protection