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TAS5751M: TAS5751M output power cannot reach the designed maximum, and it is easy to saturate

Expert 2630 points
Part Number: TAS5751M

TAS5751M output power cannot reach the designed maximum, and it is easy to saturate

One of our audio products uses 2 pcs TAS5751M

TAS5751M Powered by VDD = 24V

2X30W
One of the TAS5751M uses BTL mode to output 2X30W 8R
Problem phenomenon:
The power cannot reach the designed maximum power value,at present, it can only be saturated up to 15W.

2X20W
Another TAS5751M uses BTL mode to output 2X20W 8R
Both circuits are powered by VDD = 24V

Problem phenomenon:
The power cannot reach the designed maximum power value,at present, it can only be saturated up to 3W.

Please help to see if the schematic is normal? What causes the saturation? Thanks!

Block diagram of the whole speaker connection

2X30W Schematic


2X20W Schematic

  • One of our audio products uses 2 pcs TAS5751M

    TAS5751M Powered by VDD = 24V

    2X30W
    One of the TAS5751M uses BTL mode to output 2X30W 8R
    Problem phenomenon:
    The power cannot reach the designed maximum power value,at present, it can only be saturated up to 15W.

    2X20W
    Another TAS5751M uses BTL mode to output 2X20W 8R
    Both circuits are powered by VDD = 24V

    Problem phenomenon:
    The power cannot reach the designed maximum power value,at present, it can only be saturated up to 3W.

    Please help to see if the schematic is normal? What causes the saturation? Thanks!

  • Hi 2018,

    It's strange that the outputs of both devices saturate at different power levels. Looking at what's different between these two circuits I noticed that they have different LC filters. Do you happen to have the datasheet for the inductors you are using? It's possible that the inductors are saturating, hence why you aren't able to reach full output power. 

    Regards,

    Robert Clifton 

  • Sorry,I made a mistake. IC is in the protected state, not saturated. After IC is protected, the register cannot be read out

  • Hello 2018,

    As to this issue, please follow step by step check below:

    Software configuration,

    Is it possible AGL limit the output of power. Please share your .ppc3 source file for our further debug.

    Hardware:

    1. Do you have TI EVM board in your hand? If so, please check with EVM board for correlation with your .ppc3 file
    2. Can you check whether your power supply can deliver enough current
    3. When IC is in "protection" status as you said, please check voltage on: refer to page 17 of datasheet
    1. DVDD=3.3V?
    2. AVDD=?V, GVDD=?V
    • Then please check whether I2C communication is normal or not;
    • If I2C communication works, please read out 0x02: error status register, see page 34.

    regards,

    Alix Wan.

  • Hardware:

    1. Do you have TI EVM board in your hand? If so, please check with EVM board for correlation with your .ppc3 file

           do not have it

    1. Can you check whether your power supply can deliver enough current

           yes

    1. When IC is in "protection" status as you said, please check voltage on: refer to page 17 of datasheet
    1. DVDD=3.3V?
    2. AVDD=?V, GVDD=?V

          will checking later

    • Then please check whether I2C communication is normal or not;

            I2C dead, couldn't read the value. how could I know the error type?

    • If I2C communication works, please read out 0x02: error status register, see page 34.

            I2C dead, couldn't read the value. how could I know the error type?

  • Hello 2018,

    Please check why I2C communication is dead. When this issue is reproduced, then:

    1. Check PVDD=?V
    2. DVDD=3.3V?
    3. AVDD=?V, GVDD=?V

    Regards,

    Alix Wan.