TAS5424A: TAS5424A behavior and play mode

Hi,
When the device is first turned on the UV will be triggered as the power rises. This is normal and expected. When the register is read, the faults clear.
When you read it again the faults should be gone as you are seeing.

Are you using the EVM? What are you using for I2C communication. What are you doing with the /MUTE pin?

Hi Gregg,

I'm not using the EVM. I've soldired the circuit by myself, but generally it looks Ok to me.
The Mute pin is left floating with one capacitor attached to it. 330nF and then to Ground. For I2C I'm using Arduino UNO with attached pull-up resistors to both sda and scl (just in case I tried with 3.3 & 5V, same results).

Hi,
What is the state of the /FAULT pin?

Hi,

the state of the /FAULT pin is hight.

All registers (after the initial one of the 0x00) are reporting 0.

Regards,
Veso

And to clarify.. status registers 0x00 to 0x04 (incl.)

Hi,
I corrected the above message.

Hi,

these steps are exactly what I'm trying. Attaching logs from Serial monitor of Arduino.

serial connection established

Begin of getting status
End of getting status
Fault register 1: 48 - 110000 - 30

Begin of getting status
End of getting status
Fault register 1: 0 - 0 - 0

Begin of getting status
End of getting status
Fault register 2: 0 - 0 - 0

Begin of getting status
End of getting status
Initial state of 0x05 Register: 15 - 1111 - F

Begin of getting status
End of getting status
Initial state of 0x06 Register: 0 - 0 - 0

Begin of getting status
End of getting status
Initial state of 0x0C Register: 31 - 11111 - 1F

Begin updating of Ext5, OutputControl
End of updating of Ext5, OutputControl
Begin of getting status
End of getting status
Updated state of 0x0C: 16 - 10000 - 10

Begin of getting status
End of getting status
0x06 after writing 0x10 in 0x0C 0 - 0 - 0

Begin updating of Ext5, OutputControl
End of updating of Ext5, OutputControl
Begin of getting status
End of getting status
0x06 after writing 0x00 in 0x0C: 0 - 0 - 0

Begin of getting status
End of getting status
0x05 after writing 0x00 in 0x0C: 15 - 1111 - F

As you can see writing to 0x0C doesn't reflect on 0x06/0x05

Hi,
At the end of your sequence can you read the fault registers again. Maybe the device is seeing a fault condition and forcing the output to Hi-Z. It appears that the device cannot transition to play or there is a fault. The /MUTE pin must not be pulled high or low externally. It must be allowed to charge and discharge the 330nF capacitor, unhindered. If it goes into fault immediately at switching, it could mean that the inductors you used are not correct.
1. Use an oscilloscope and look at the /MUTE pin during the Hi-Z to Mute and the MUTE to Play transitions. Look at the /MUTE pin in figure 23 of the datasheet. You should see the later half of waveform as shown.
2. Please provide the inductor part number and manufacturer. I will check to see if this one is proper.

Hi,

the strange thing that I discovered today is that if I write 0x40 -> 0x0B the transition in Mute and then Play mode is successful.
/MUTE & /FAULT pins are high. Also have a signal right after channels pins.

Unfortunately something is happening after the LC filter and as you suggested it might be because of wrong inductors. The ones I've placed are with the following description: DR CL330uH CW8A. If they are not proper can you suggest one?

Regards,
Veselin

The inductor part number looks like it is a 330uH. I do not know the part, but it appears to be too large of value for an audio amplifier. What criteria did you use to use this value? TI recommends a 10uH inductor for a 4 ohm and 2 ohm load.

You turned off the DC offset protection. By turning this off you allow DC offset to occur. Measure the DC offset on the speaker outputs when this occurs and report back.