TAS2563: Current cunsumption during Idle vs Mute

Hello,

I am looking into your inquiry. Please expect a response by the end of the week. Thank you for your patience!

Regards,
Sydney Northcutt

additional info.

TAS2563 Vbat always connect to battery but IOVDD (1.8V) is control by our processor. Attach is the power up sequence upon power button press

 below is zoom in detail for sw reset & write init register

Then the next is PA go into mute mode after tone

Beside that, what is the correct sequence from ON to MUTE to SHUTDOWN? Need to add delay in between?

What is the function of load diagnostic? What is the effect between ON & OFF?

Hello,

Thank you for the additional information. You mentioned there are two cases, one where you manually program but what is the other one? Using PPC3? Are you programming the same sequence manually and with PPC3 but seeing different responses?

Also, what are you using to measure the current? The shutdown current should be less than 1 mA. 

Load diagnostic checks if the speaker terminal has an open or short. ldg_mode_on runs a diagnostic check regardless of the MODE setting. If diagnostics is set by the MODE register the device will run diagnostics and then go to active mode if errors are not detected. 

Regards,
Sydney Northcutt

Hi,

I think I had asked too many things at once and cause confusion for you. Let's settle 1 by 1... ^_^

Our product is BT accy, VBAT is always connected to battery and IOVDD only present when power ON.

Our product only have ACTIVE or MUTE mode. So during no audio playback, the unit is in MUTE instead of  sw shutdown.

The reason why we didn't go to SW shutdown mode because of latency concern.

We notice that the idle current for VBAT during ACTIVE mode (~14mA) is lower than MUTE mode (~24mA). Why?

FYI....  This is the config for the product output LC filter

Below are all the register setting we configure in our product. Please comment is there any errors with it?

Do it have any timing sequence requirement to write TAS2563 register? Example: If i want to ask PA from Active -> Mute -> Shutdown. Since all are same register address.

Hello,

I appreciate the clarification! This is very clear. 

The active mode (with no audio) and mute are very similar so I am not sure for a difference in current at the moment, but let me replicate this and find the reasoning. 

Regards,
Sydney Northcutt

Hello,

Apologies for the delay here. 

Using your script, I do not see a difference in current for mute or active mode (with no audio playing). I have tried various sequences as well between shutdown, mute, and active. Each time mute and active mode pull around 5 mA from Vbat. The two modes are similar in that the class-d output it still switching but no audio data is transmitted, so the current should be similar. 

This is lower than what you are recording in general, so I am wondering if the current measurement device you are using is causing this issue. I am using a HV Power Monitor to provide and measure Vbat. The Keithley 2420 source meter is also a good option if you have anything similar available. 

There is also no specific sequencing needed between the different modes. 

Regards,
Sydney Northcutt

how about our LC filter configuration, will it cause the strange behavior? 

We are using Keysight 1147B current probe with Agilent MSO7104A oscilloscope. 

Hello, 

The LC filter should not cause a difference as the output for mute mode and active mode (with no audio playing) is the same. You can see this by probing the class-d output on the scope.

I have used a similar scope probe before and found inaccuracy for small resolution measurements even when the probe is degaussed due to the limited resolution and noise. Maybe you can try some source meter with a fine resolution for Vbat or use a sense resistor to conduct these measurements?  

Regards,
Sydney Northcutt