9.3.5.1 Load Diagnostics Sequence

The load diagnostic function runs on deassertion of STANDBY or when the device is in a fault state (dc detect, overcurrent, overvoltage, undervoltage, or 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 5 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 11.
Figure 12 illustrates how the diagnostics determine the load based on output conditions.

Figure 11. Load Diagnostics Sequence of Events

Figure 12. Load Diagnostic Reporting Thresholds