adau1961 Analog Devices, Inc., adau1961 Datasheet - Page 32

• Manufacturer Part Number: adau1961
• Description: Stereo, Low Power, 96 Khz, 24-bit Audio Codec With Integrated Pll Adau1961
• Manufacturer: Analog Devices, Inc.

ADAU1961
Noise Gate Mode 2 (see Figure 41) is selected by setting the
NGTYP[1:0] bits to 10. In this mode, the ADAU1961 improves
the sound of the noise gate operation by first fading the PGA
gain over a period of about 100 ms to the minimum PGA gain
value. The ADAU1961 does not do a hard mute after the fade is
complete, so some small background noise will still exist.
ENABLE SIGNAL
NOISE GATE
INTERNAL
ANALOG
OUTPUT
DIGITAL
INPUT
MUTE
GAIN
Figure 41. Noise Gate Mode 2 (Analog Fade)
250ms
100ms
THRESHOLD
MIN GAIN
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Noise Gate Mode 3 (see Figure 42) is selected by setting the
NGTYP[1:0] bits to 11. This mode is the same as Mode 2 except
that at the end of the PGA fade gain interval, a digital mute is
performed. In general, this mode is the best-sounding mode,
because the audible effect of the digital hard mute is reduced by
the fact that the gain has already faded to a low level before the
mute occurs.
ENABLE SIGNAL
NOISE GATE
INTERNAL
ANALOG
OUTPUT
DIGITAL
INPUT
Figure 42. Noise Gate Mode 3 (Analog Fade/Digital Mute)
MUTE
GAIN
250ms
100ms
THRESHOLD
MIN GAIN