TLV320ADC5140: Date transmission delay time

Hi Amber, 

We call this time delay a group delay in the datasheet. This delay is impacted by any filters and biquads implemented in the device. You can calculate the group delay in 8.3.6.7 of the d/s depending on your sampling frequency; by default the device has a linear phase filter enabled. 

In PurepathConsole3, you can model the group delay as a response to the filter implemented by changing the plot type.

Regards,

Hi Daveon，

1. How to calculate group delay time if sampling rate is 48k? could you help give me an example if enable a linear phase filter?

2.If I want a low latency, should I select Ultra-low latency filters?

3. I find signal chain flow has so many blocks, but why only decimation filters can impact the group delay? other block don't impact the delay?

Thanks.

Amber

Hi Amber,

1. For example, in your image the group delay would be 17.1 / 48000 kHz = 229µs

2. You can select low latency or ultra-low latency, the difference is the audio pass-band and phase response. The data tables for low latency (8.3.6.7.2) vs ultra-low latency (8.3.6.7.3) have their own differences and trade-offs.

3. You're correct, I assume a lot of the specifics to time delay in each block exist and the designers may know this detail. However that changes on each user configuration, so it's important to note which blocks have the most impact (such as filtering, or AGC/DRE if enabled) and count the small blocks (phase/gain calibration) negligible, especially if not used. 

To this point, determine all the block that are being used, utilize the application notes that have time delay details and datasheet to approximate the total.

Regards