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TLV320AIC23B: TLV320AIC23B Power Supply Questions

Richard Elmquist
Mastermind 45250 points

Part Number: TLV320AIC23B

My customer is asking the following questions regarding the TLV320AIC23B:

The S/W team has had multiple issues with this codec, (channel bounce, MSB bits at different positions, sample packets out of sequence), but when this occurs a s/w reset or hard power cycle solves this until the next boot cycle.

Question: Has TI seen this type of complaint before?

We are spinning the design, and I wanted to solve this problem.

The data sheet for TLV320AIC23 says: DVDD may not exceed BVDD 0.3V; BVDD may not exceed AVDD 0.3V or HPVDD 0.3. Our volume production design meets this requirement, as follows: a. AVDD = HPVDD = 3.0V (this is created from a LDO from the 3,3V supply) b. BVDD = DVDD = 3,3V. Our design meets the data sheet spec.

A separate article SLEA037 says the supply voltage has different requirement to the data sheet, see "4.1 Power Restrictions" Can you tell us what is the correct voltage rules and are there any power up sequencing for the power supply ?

Have we seen issues similar to those reported by the customer? Could the supply voltage restrictions stated in the application note (SLEA037) be the cause of the issues that they are seeing? Is the information contained in this application note valid? It is still listed as a preliminary document. Please let me know if they should follow the application note of the data sheet specifications.

Are there any other problems that could cause the issues that the customer has seen over the years with this IC?

Thanks for your help with this questions!

Richard Elmquist

  • 0
    TI__Guru* 84915 points
    Hi, Richard,

    Our audio codecs are strongly related to power supply behavior. As noticed, the audio codecs have multiple power supplies due to the different blocks and features. So, they also require particular considerations during the design.

    - Ensure that all the power supplies are well regulated and in the datasheet recommended range. Eliminate noise at the power supplies since it may be added in the codec audio signals.
    - The power supplies require of a particular sequence in order to get a correct behavior. We recommend to start powering up the digital power supplies (DVDD, BVDD). Then, once these supplies are stable, power up the analog supplies (AVDD, HPVDD).
    - Ensure that the decoupling capacitors are placed as close as possible to the power supply pins. We recommend to use decoupling capacitors of 10uF and 0.1uF values.
    - Finally, separate the digital activity from analog activity in the layout design. This includes the ground planes and analog and digital lines. The ground planes must be separated and joined with a 0-ohm resistor or a small ground trace.

    Please let me know if you have additional questions or comments.

    Best regards,
    Luis Fernando Rodríguez S.
  • 0 in reply to Luis Fernando Rodriguez S.
    TI__Mastermind 45250 points

    Luis,

    Thanks for your response!

    Can you comment on the actual voltages used for the supplies as it relates to the last part of the question?

    The data sheet for TLV320AIC23 says: DVDD may not exceed BVDD 0.3V; BVDD may not exceed AVDD 0.3V or HPVDD 0.3. Our volume production design meets this requirement, as follows: a. AVDD = HPVDD = 3.0V (this is created from a LDO from the 3,3V supply) b. BVDD = DVDD = 3,3V. Our design meets the data sheet spec.

    A separate article SLEA037 says the supply voltage has different requirement to the data sheet, see "4.1 Power Restrictions" Can you tell us what is the correct voltage rules and are there any power up sequencing for the power supply ?

    There appears to be some inconsistencies between the two documents and the customer wants to know if his power supply voltages are correct.

    Thanks for your help with this!

    Richard Elmquist

  • 0 in reply to Richard Elmquist
    TI__Guru* 84915 points
    Hi, Richard,

    I would recommend to modify the power supplies values to respect the mentioned in SLEA037. The Datasheet mentions the following line:

    "DVDD may not exceed BVDD + 0.3V; BVDD may not exceed AVDD + 0.3V or HPVDD + 0.3"

    This line is mentioned under the absolute maximum ratings. So, customer is configuring the power supplies on the absolute limit (BVDD = AVDD + 0.3V = HPVDD + 0.3V), which is not recommended on the designs. Marginal conditions may generate a damage on a certain percentage of units.

    So, in order to avoid these problems, I would recommend to use the recommended operating conditions of datasheet. The nominal values (AVDD, HPVDD, BVDD = 3.3V; DVDD = 1.5V) are suggested to get the best performance in the audio codec.

    Best regards,
    Luis Fernando Rodríguez S.
  • 0 in reply to Luis Fernando Rodriguez S.
    TI__Mastermind 45250 points

    Luis,

    Thanks for your response!

    I will let you now if the customer has any further questions.

    Thanks again.

    Richard Elmquist