TPA6166A2: Question of Frequency Response of Microphone Amplifier of TPA6166

Hi Sirs,

We got -3dB corner frequency at 30Hz with TPA6166 EVM. We tried to short the lowpass filter on R1 but not improved.
Is it doable to make flat frequency response from 20Hz to 20kHz with the microphone amp of the TPA6166?

Would you please provide official frequency response specification of the microphone amplifier of the TPA6166 device?




CH1: R1 stuffed, CH2: R2 short

100mV Input signal at SLEEVE, Measured signal at NOUTN, 2.2kR load at MOUTN.

 





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TPA6166 configuration:

#op i2c Addr Data Comment
w 80 1e 19 #Enable Registers 3
w 80 04 08 #Interrupt Mask Register 1
w 80 05 00 #Interrupt Mask Register 2
w 80 07 bb #Left Headphone Volume Register = +2dB
w 80 08 79 #Right Headphone Volume Register = LR Tracking
w 80 09 c7 #Microphone/Ground Control = +24dB
w 80 12 01 #Reserved Registers
w 80 13 45 #Reserved Registers
w 80 1a 95 #Jack Detect AC Test Settings
w 80 1e 01 #semi auto mode
w 80 1d 80 #Enable Registers 2
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Thank you and Best regards,

Wayne Chen
03/29/2021