The load diagnostic function runs on de-assertion of STANDBY or when the device is in a fault state (dc detect, overcurrent, overvoltage, undervoltage, and overtemperature). During this test, the outputs are in a Hi-Z state. The device determines whether the output is a short to GND, short to PVDD, open load, or shorted load. The load diagnostic biases the output, which therefore requires limiting the capacitance value for proper functioning; see the Recommended Operating Conditions. The load diagnostic test takes approximately 229 ms to run. Note that the check phase repeats up to five times if a fault is present or a large capacitor to GND is present on the output. On detection of an open load, the output still operates. On detection of any other fault condition, the output goes into a Hi-Z state, and the device checks the load continuously until removal of the fault condition. After detection of a normal output condition, the audio output starts. The load diagnostics run after every other overvoltage (OV) event. The load diagnostic for open load only has I²C reporting. All other faults have I²C and FAULT pin assertion.

The device performs load diagnostic tests as shown in Figure 7-2.

Figure 7-3 illustrates how the diagnostics determine the load based on output conditions.

Figure 7-2 Load Diagnostics Sequence of Events

Figure 7-3 Load Diagnostic Reporting Thresholds