ACS422A68TAGZBX8 IDT, ACS422A68TAGZBX8 Datasheet - Page 55

• Manufacturer Part Number: ACS422A68TAGZBX8
• Description: Interface - CODECs
• Manufacturer: IDT

Specifications of ACS422A68TAGZBX8

• Rohs: yes
• Part # Aliases: IDTACS422A68TAGZBX8

ACS422x68
LOW-POWER, HIGH-FIDELITY, INTEGRATED CODEC
©2011 INTEGRATED DEVICE TECHNOLOGY, INC.
4.7.
The ACS422x68 has an automatic level control to achieve recording volume across a range of input signal levels. The
device uses a digital peak detector to monitor and adjusts the PGA gain to provide a signal level at the ADC input. A
range of adjustment between –6dB and –28.5dB (relative to ADC full scale) can be selected. The device provides pro-
grammable attack, hold, and decay times to smooth adjustments. The level control also features a peak limiter to pre-
vent clipping when the ADC input exceeds a threshold. Note that if the ALC is enabled, the input volume controls are
ignored.
R6 (06h)
Left ADC
Digital Volume
R7 (07h)
Right ADC
Digital Volume
Register Address
4.6.1.
Automatic Level Control (ALC)
4.7.1.
ADC Digital Registers
ALC Operation
When ALC is enabled, the recording volume target can be programmed between –6dB and –28.5dB
(relative to ADC full scale). The ALC will attempt to keep the ADC input level to within +/-0.5dB of the
target level. An upper limit for the PGA gain can also be imposed, using the MAXGAIN control bits.
Bit
7:0
7:0
ADCVOL_R
ADCVOL_L
Label
[7:0]
[7:0]
Table 63. L/R ADC Digital Volume Registers
Figure 21. ALC Operation
Type
RW
RW
10111111
10111111
Default
55
(0dB)
(0dB)
Left ADC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -71.25dB
0000 0010 = -70.875dB
... 0.375dB steps up to 1111 1111 = +24dB
Note: If ADCVOLU is set, this setting will take effect
after the next write to the Right Input Volume register.
Right ADC Digital Volume Control
0000 0000 = Digital Mute
0000 0001 = -71.25dB
0000 0010 = -70.875dB
... 0.375dB steps up to 1111 1111 = +24dB
Description
ACS422X68
V1.6 01/13