sta538 STMicroelectronics, sta538 Datasheet - Page 17

• Manufacturer Part Number: sta538
• Description: 2 X 1.3 W Class-d Amplifier With Analog Or Digital Input 2.0 Multichannel Digital Audio Processor With Ffx
• Manufacturer: STMicroelectronics

STA538
4.3
Volume control and gain
The volume control structure of the STA538 consists of individual volume registers for each
channel and a master volume register that provides an offset to each channel’s volume
setting. The individual channel volumes are adjustable in 0.5 dB steps from +36 dB to
-91.5 dB. As an example, if register LVOL = 0x00 or +36 dB and register MVOL = 0x18 or
-12 dB, then the total gain for the left channel is +24 dB.
When the mute bit is set to 1, all channels are muted. The volume control provides a soft
mute with the volume ramping down to mute in 4096 samples from the maximum volume
setting at the internal processing rate (~48 kHz).
Table 12.
Table 13.
LVOL/RVOL[7:0]
MVOL[7:0]
0xFE
0xFF
0xFF
0x00
0x01
0x02
0x78
0x00
0x01
0x02
0x47
0x48
0x49
Master volume offset as a function of register MVOL
Channel volume as a function of registers LVOL and RVOL
…
…
…
…
…
Volume offset from channel value
Hard master mute
+35.5 dB
-91.5 dB
Volume
+0.5 dB
+36 dB
+35 dB
-0.5 dB
-105 dB
-0.5 dB
-60 dB
0 dB
-1dB
0 dB
…
…
…
…
…
Digital processing
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