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LM49450: Asking for the LM49450 pop performacne spec

SHH
Mastermind 32196 points
Part Number: LM49450

Hi Team,

Can LM49450 meet the following spec from IC side for customer request? Please exclude the system design aspect.

Headphone out level 300mV/32Ω, pop noise<-60dB


Thanks,
SHH

  • 0
    TI__Guru** 109245 points
    Hi SHH,

    Unfortunately there is not an available board for testing purpose. However judging from output power spec of this device I think it should be able to reach 300mV on 32Ω load.
    Also, as this device has ground centered headphone outputs the pop noise should be low.

    Best regards,
    -Ivan Salazar
    Audio Applications Engineer - Low Power Audio & Actuators
  • 0 in reply to Ivan Salazar
    TI__Mastermind 32196 points
    Hi Ivan,

    Customer uses Nvidia chip to send the I2S signal to LM49450. Customer originally output headphone voltage level set at 150mV. In 150mV conditions, the pop sound pass the pop noise test(-60dB)
    Now, customer would like to increase the output voltage from 150mV to 300mV.
    However, the pop noise is -45dB.

    Could you please help customer's questions below?
    1. customer only add 6dB to increase the output voltage from 150mV to 300mV.
    Why the pop noise performance is change from -60dB to -45dB? Does that make sense?

    Thanks,
    SHH
  • 0 in reply to SHH
    TI__Guru** 109245 points
    SHH,

    As said in my last message, unfortunately there is not an evaluation board available for me to verify this.
    Is this pop noise caused when coming out of mute state or while powering up? One thing that can be tried is to reduce gain when enabling/disabling mute. Also enabling mute before powering down could help.

    Best regards,
    -Ivan Salazar
    Audio Applications Engineer - Low Power Audio & Actuators