The oscillator frequency can be trimmed by external control of the FREQ_ADJ pin.

To reduce interference problems while using radio receiver tuned within the AM band, the switching frequency can be changed from nominal to higher values. These values are chosen such that the nominal and the higher value switching frequencies together results in the fewest cases of interference throughout the AM band. The oscillator frequency can be selected by the value of the FREQ_ADJ resistor connected to GND in controller mode according to the description in the Section 6.5 table.

For peripheral mode operation, turn off the oscillator by pulling the FREQ_ADJ pin to AVDD. This configures the OSC_I/O pins as inputs to be peripherals from an external differential clock. In a controller/peripheral system inter channel delay is automatically setup between the switching of the audio channels, which can be illustrated by no idle channels switching at the same time. This does not influence the audio output, but only the switch timing to minimize noise coupling between audio channels through the power supply to optimize audio performance and to get better operating conditions for the power supply. The inter channel delay is setup for a peripheral device depending on the polarity of the OSC_I/O connection such that a peripheral mode 1 is selected by connecting the controller device OSC_I/O to the peripheral 1 device OSC_I/O with same polarity (+ to + and - to -), and peripheral mode 2 is selected with the inverse polarity (+ to - and - to +).