SLES023D December 2001 – December 2016 PCM1802
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.
The PCM1802 device is suitable for wide variety of cost-sensitive consumer applications requiring good performance and operation with a 5-V analog supply and 3.3-V digital supply.
Figure 28 illustrates a typical circuit connection diagram in which the cutoff frequency of the input HPF is about 8 Hz.
For this design example, use the parameters listed in Table 10 as the input parameters.
|Analog input voltage||0 VP–P to 3 VP–P|
|Output||PCM audio data|
|System clock input frequency||2.048 MHz to 49.152 MHz|
|Output sampling frequency||8 kHz to 96 kHz|
|Power supply||3.3 V and 5 V|
The FMT, MODE, OSR, and BYPASS control pins are controlled by tying up to VDD, down to GND, or driven with GPIO from the DSP or audio processor.
In this application a DSP or audio processor acts as the audio master, and the PCM1802 acts as the audio slave. This means the DSP or audio processor must be able to output audio clocks that the PCM1802 can use to process audio signals.
For the analog input circuit an AC-coupling capacitor must be placed in series with the input. This removes the DC component of the input signal. An RC filter can also be implemented to filter out of band noise to reduce aliasing. Equation 1 calculates the cutoff frequency of the optional RC filter for the input.