What are the mute ramp times in the AD193x codecs? by BrettG
The AD193x codecs are often used in conjunction with the SigmaDSP products. Recently, a customer asked me how the volume ramping worked on the ADC and DAC mute controls.
The mute in the ADC is a digital mute with a 10-bit, 1024 LRCLKs ramp up/down time.
The calculation for the ADC mute ramp is:
Ramp Time (ms) = 1024 / Sample Rate (kHz)
For example, if the sample rate is 48 kHz,
1024 / 48 kHz = 21.333 ms
It is a linear ramp, not a logarithmic ramp.
The volume control is also linear and 10-bit, hence the 1024 steps.
In the DAC, is it a log scale, 8-bit, -96dB column, so the mute would take 256 LRCLKs.
The calculation for the DAC mute ramp is:
Ramp Time (ms) = 256 / Sample Rate (kHz)
For example, if the sample rate is 48 kHz,
256 / 48 kHz = 5.333 ms
