The PCM175x devices include a power-on reset function. Figure 21 shows the operation of this function. With the system clock active and VCC > 3 V (typical, 2.2 V to 3.7 V), the power-on reset function is enabled. The initialization sequence requires 1024 system clocks from the time VCC > 3 V (typical, 2.2 V to 3.7 V).
During the reset period (1024 system clocks), the analog output is forced to the bipolar zero level, or VCC/2. After the reset period, an internal register is initialized in the next 1/fS period and if SCK, BCK, and LRCK are provided continuously, the PCM175x devices provide proper analog output with unit group delay against the input data.