NAU8812EVB Nuvoton Technology Corporation of America, NAU8812EVB Datasheet - Page 32

• 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

The PGA gain comes from either the ALC block when it is enabled or from the PGA gain register setting when the
ALC is disabled. Zero crossing detection may be enabled to cause PGA gain changes to occur only at an input zero
crossing. Enabling zero crossing detection limits clicks and pops that may occur if the gain changes while the input
signal has a high volume.
There are two zero crossing detection enables:


If the zero crossing function is enabled (using either register) and SCLKEN[0] address (0x07) is asserted, the zero
cross timeout function may take effect. If the zero crossing flag does not change polarity within 0.25 seconds of a
PGA gain update (either via ALC update or PGA gain register update), then the gain will update. This backup system
prevents the gain from locking up if the input signal has a small swing and a DC offset that prevents the zero crossing
flag from toggling.
emPowerAudio
Datasheet Revision 2.0
12.4.6. Zero Crossing
Register ALCZC[8] address (0x21) – is only relevant when the ALC is enabled.
Register PGAZC[7] address (0x2D) – is only relevant when the ALC is disabled.
PGA Output
PGA Input
PGA Gain
™
Figure 16: ALC Operation with Noise Gate Enabled
Page 32 of 109
Noise Gate Threshold
NAU8812
January 2011