ZHCSAC2C August 2012 – October 2018 PCM5121 , PCM5122
PRODUCTION DATA.
The PCM512x devices have an internal, fixed band-gap reference voltage, with default operation in VREF mode. No external decoupling capacitor is required for this mode.
The PCM512x devices can be operated with a common-mode voltage output (VCOM mode) at the VCOM pin by setting Page 1, Register 1, D(0) to 1. In this mode, an external decoupling capacitor is required.
When using this DAC in VREF mode, the output-signal voltage is independent of the power-supply voltage: The D/A conversion gain in VREF mode yields a 2.1-Vrms output voltage with a digital full-scale input. However, in VREF mode, an output waveform may clip due to the limitations that may be present in the analog power supply voltage. On the other hand, the full-scale output voltage in VCOM mode is proportional to the analog power supply AVDD (for example, (2.1 × AVDD / 3.3) Vrms).