DAC11001B: THD TEST DATA

Choi Se Young

Part Number: DAC11001B

Hello,

I am currently evaluating the DAC11001B and reaching out with an inquiry, as the measured THD performance does not match the specifications listed in the datasheet.

Currently, I am getting a THD measurement of approximately 0.0009%, whereas the datasheet (PDF) indicates around 0.000398% under the same conditions.

Despite using identical test conditions—a filter range of 22Hz to AES17 (40kHz), a 192kHz sample rate, and a 1kHz tone frequency—there is a significant discrepancy in the values, which I am trying to understand. I also observed the same results at the buffer stage following the DAC.

Could you please help clarify this issue?

Ti_DAC11001A_audio.pdf

6 days ago

0 Subrateshvar Dwivedi 6 days ago

TI__Prodigy 40 points

Hi Choi,

Please share details mentioned before I can help in debugging your THD performance measurement issue -
1. DAC11001B schematic design
2. DAC11001B power supply & reference input values
3. Spectrum analyzer instruments details

Thanks,
Subrat

0 Choi Se Young 6 days ago

Prodigy 10 points

Thank you for your reply
i just uploaded circuit diagram
Main Voltage : Battery : 3.8~ 4.3V
and i measured using Audio precision

0 Choi Se Young 6 days ago in reply to Subrateshvar Dwivedi

Prodigy 10 points

THD_Issue.pdf

0 Subrateshvar Dwivedi 6 days ago

TI__Prodigy 40 points

Choi,
Based on the schematic, the power supply rails (AVDD=+5V, DVDD=+5V, IOVDD=+3.3V, VCC=+15V, and VSS=-15V) appear correct. Now coming to Reference voltages for both the DAC LP and DAC LN, please confirm that the REFPF =+10V and REFNF =-10V. It looks like REFPF and REFNF are tied to the same voltage for each DAC (both +10V for DAC LP and both -10V for DAC LN). Please see the attached screenshot.

0 Choi Se Young 6 days ago in reply to Subrateshvar Dwivedi

Prodigy 10 points

Hello i choose 5v ref now and i already changed the REF Voltage like your pic before

0 Subrateshvar Dwivedi 6 days ago in reply to Choi Se Young

TI__Prodigy 40 points

Choi,

since you are using the APX555 for harmonic measurements, please verify that the high-performance sine analyzer settings in the APX555 signal path configuration are correctly configured for this measurement.

for further discussion we can connect on the email. I have shared a mail for the same.

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DAC11001B: THD TEST DATA