NAU8812EVB Nuvoton Technology Corporation of America, NAU8812EVB Datasheet - Page 27

• 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 ALC is enabled by setting ALCEN[8] address (0x20) bit to HIGH. The ALC has two functional modes, which is
set by ALCM[8] address (0x22).


When the ALC is disabled, the input PGA remains at the last controlled value of the ALC. An input gain update must
be made by writing to the PGAGAIN[5:0] address (0x2D). A digital peak detector monitors the input signal amplitude
and compares it to a register defined threshold level ALCSL[3:0] address (0x21).
The registers listed in the following section allow configuration of ALC operation with respect to:




emPowerAudio
Datasheet Revision 2.0
Normal mode (ALCM = LOW)
Peak Limiter mode (ALCM = HIGH)
ALC target level
Gain increment and decrement rates
Minimum and maximum PGA gain values for ALC operating range
Hold time before gain increments in response to input signal
-39dB
™
gate threshold
Input < noise
Input
Pin
-39dB
ALC operation range
Target ALCSL -6dB
PGA
Figure 11: ALC Response Graph
Input Level
Figure 10: ALC Block Diagram
-6dB +6dB
ADC
Page 27 of 109
Gain (Attenuation) Clipped
at ALCMNGAIN -12dB
Filter
Rate Convert/ Decimator
Sinc
Decimator
Digital
ALC
+33 dB
-12 dB
0 dB
PGA Gain
Digital
Filter
ALCNEN = 1
ALCNTH = -39dB
MIC Boost Gain = 0dB
ALCSL = -6dB
ALCMNGAIN = -12dB
ALCMXGAIN = +35.25dB
NAU8812
January 2011