NAU8812EVB Nuvoton Technology Corporation of America, NAU8812EVB Datasheet - Page 38

• 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

In audio and voice systems, any time there is a sudden change in voltage to an audio signal, an audible pop or click
sound may be the result. Systems that change inputs and output configurations dynamically, or which are required to
manage low power operation, need special attention to possible pop and click situations. The NAU8812 includes
many features which may be used to greatly reduce or eliminate pop and click sounds. The most common cause of a
pop or click signal is a sudden change to an input or output voltage. This may happen in either a DC coupled system,
or in an AC coupled system.
The strategy to control pops and clicks is similar for either a DC coupled system, or an AC coupled system. The case
of the AC coupled system is the most common and the more difficult situation, and therefore, the AC coupled case
will be the focus for this information section. When an input or output pin is being used, the DC level of that pin will
be very close to half of the VDDA voltage that is present on the VREF pin. The only exception is that when outputs
are operated in the 5-Volt mode known as the 1.5x boost condition, then the DC level for those outputs will be equal
to 1.5xVREF. In all cases, any input or output capacitors will become charged to the operating voltage of the used
emPowerAudio
Datasheet Revision 2.0
12.6.3. Unused Analog I/O
MIC+
MIC-
AUX
™
VREF
AUXEN[6]
NMICPGA[1]
PMICPGA[0]
DCBUFEN[8]
IOBUFEN[2]
(0x01)
(0x2C)
(0x2C)
(0x01)
(0x01)
Figure 20: Tie-off Options for the Speaker and MONO output Pins
30k
30k
40k
R
R
SBUFL[6]
SBUFH[7]
1.5 x VREF
1.0 x VREF
(0x4F)
(0x4F)
Page 38 of 109
SNSPK[5]
SMOUT[3]
SPSPK[4]
(0x4F)
(0x4F)
(0x4F)
MOUTBST[3] = 0
MOUTBST[3] = 1
(0x31)
(0x31)
30K
30K
30K
1K
1K
1K
AOUTIMP[0]
(0x31)
NAU8812
January 2011
MOUT
SPKOUT+
SPKOUT-