MAX9856ATL/V+ Maxim Integrated, MAX9856ATL/V+ Datasheet - Page 29

• Manufacturer Part Number: MAX9856ATL/V+
• Description: Interface - CODECs Low-Power Audio Codec With Directdrive. Headphone Amplifiers
• Manufacturer: Maxim Integrated
• Series: MAX9856r

Specifications of MAX9856ATL/V+

• Resolution: 18 bit
• Interface Type: Serial (I2C)
• Number Of Adcs: 2
• Number Of Dacs: 2
• Operating Supply Voltage: 1.71 V to 3.6 V
• Supply Current: 2.9 mA
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 1.71 V
• Thd Plus Noise: 82 dB

AGC Register Bit Description (continued)
AGCHLD
AGCSRC
AGCATK
AGCSTH
BITS
______________________________________________________________________________________
AGC Attack Time. The attack time is the time it takes to reduce the gain after the input signal has
exceeded the threshold level. The gain attenuation during attack is exponential and the attack time is
defined as one-time constant rather than the time it takes to reach the final gain:
00—3ms
01—12ms
10—50ms (recommended)
11—200ms
AGC Hold Time. Hold time is the delay before the AGC release begins. The hold time counter starts
whenever the signal drops below the AGC threshold and is reset by any signal that exceeds the
threshold:
00—AGC disabled
01—50ms
10—100ms (recommended)
11—400ms
AGC and Noise Gate Signal Source. Selects the audio signal that the AGC and noise gate circuitry
monitors:
0—Left-channel ADC output
1—Left-channel + right channel ADC output (results in 3dB lower threshold for coherent signals)
AGC Threshold. Sets the signal level at which the AGC begins gain reduction. The signal is monitored
after the ADC output gain has been applied.
DirectDrive Headphone Amplifiers
Low-Power Audio CODEC with
AGCSTH
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
AGC THRESHOLD LEVELS
FUNCTION
LEVEL (dB)
-10
-11
-12
-13
-14
-15
-16
-17
-18
-3
-4
-5
-6
-7
-8
-9
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