SLASET3D April 2019 – January 2024 TAS2563
PRODUCTION DATA
The gain from audio input to speaker terminals is controlled by setting the amplifier’s output level and digital volume control (DVC).
Amplifier output level settings are presented in dBV (dB relative to 1 Vrms) with a full scale digital audio input (0 dBFS) and the digital volume control set to 0 dB. It should be noted that these levels may not be achievable because of analog clipping in the amplifier, so they should be used to convey gain only. Table 7-55 below shows gain settings that can be programmed via the AMP_LEVEL register.
AMP_LEVEL[4:0] | FULL SCALE OUTPUT | |
---|---|---|
dBV | VPEAK (V) | |
| 8 | 3.55 |
| 8.5 | 3.76 |
| 9 | 3.99 |
| ... | ... |
| 16 | 8.92 |
| ... | ... |
| 17.5 | 10.60 |
| 18 | 11.23 |
| Reserved | Reserved |
Equation 1 calculates the amplifiers output voltage.
where
Settings greater than 0xC8 are interpreted as mute. When a change in digital volume control occurs, the device ramps the volume to the new setting based on the DVC_RAMP register bits. If DVC_RAMP is set to 0x0000 0000, volume ramping is disabled. This can be used to speed up startup, shutdown and digital volume changes when volume ramping is handled by the system master.
The digital voltage control registers DVC_PCM represent the volume in a 2.X format. To calculate the value to write to these 4 registers apply the following formula to the desired dB DVC_PCM = round(10^(dB/20)*2^30).
A volume ramp rate can be set using DVC_RAMP and represents a rate in 1.X format. To calculate the value to write to these 4 registers apply the following formula DVC_RAMP = round((1-exp(-1/(0.2*fs*time in seconds)))*2^31).
DVC_PCM[31:0] | VOLUME (dB) |
---|---|
| -110 |
| ... |
| 0 (default) |
| ... |
| 2 |
DVC_RAMP[31:0] | RAMP RATE @ 48kHz (s) |
---|---|
| 0 |
| |
| 1 s |
where