NAU8812EVB Nuvoton Technology Corporation of America, NAU8812EVB Datasheet - Page 16

• Manufacturer Part Number: NAU8812EVB
• Description: BOARD EVAL FOR NAU8812
• Manufacturer: Nuvoton Technology Corporation of America
• Series: emPowerAudio™r

Specifications of NAU8812EVB

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12. FUNCTIONAL DESCRIPTION
The NAU8812 is a MONO Audio CODEC with very robust ADC and DAC. The device provides one single ended
auxiliary input (AUX pin) and one differential microphone input (MIC- & MIC+ pins). The auxiliary input (AUX) can be
configured to sum multiple signals into a single input. It has three different amplification paths with a total gain of up
to +55.25dB. The differential input also has amplification paths similar to auxiliary input.
The device also has an internal configurable biasing circuit for biasing the microphone, which in turn reduces external
components. The PGA output has programmable ADC gain. An advanced Sigma Delta DAC is used along with
digital decimation and interpolation filters to give high quality audio at sample rates from 8 kHz to 48 kHz. The Digital
Filter blocks include ADC high pass filters, and Notch filter. The device has two output mixers, one for MONO output
and the other for the speaker output. It also has one input mixer.
The NAU8812 has two different types of serial control interface 2-Wire and SPI for device control. 2-Wire and SPI
are hardware selectable through MODE pin on the device. The device also supports I
Justified and Right Justified for audio interface.
The device can operate as a master or slave device. It can operate with sample rates ranging from 8 kHz to 48 kHz,
depending on the values of MCLK and its prescaler. The NAU8812 includes a PLL block, where it takes the external
clock (MCLK pin) to generate other clocks for the audio data transfer such as Bit clock (BCLK), Frame sync (FS), and
I
pin. The power control registers help save power by controlling the major individual functional blocks of the NAU8812.
The NAU8812 has two different types of microphone inputs single ended and differential. Figure 3 shows the
different paths that the input signals can take.
All inputs are maintained at a DC bias at approximately half of the VDDA supply voltage. Connections to these inputs
should be AC-coupled by means of DC blocking capacitors suitable for the device application.
The single ended auxiliary input (AUX) has three different paths to MONO output (MOUT).
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emPowerAudio
Datasheet Revision 2.0
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S clocks. The PLL can also configure a separate programmable clock for the use in the system through CSb/GPIO
12.1.
12.1.1. The Single Ended Auxiliary Input (AUX)
Directly connected to the MONO Mixer or Speaker Mixer to MOUT or SPKOUT+ and SPKOUT- respectively
Connect through the PGA Boost Mixer which has a range of -12dB to +6dB
Connect through both the input PGA Gain (range of -12dB to +35.25 dB) and PGA Boost Mixer (range of 0db or
+20dB)
INPUT PATH
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S, PCM time slotting, Left
NAU8812
January 2011