DRV602: Noise Floor of DRV602 and DRV603

yoshiki hasebe

Mastermind 6385 points

Part Number: DRV602
Other Parts Discussed in Thread: DRV603

Dear Sirs,

My Customer asked us about "Noise Floor" of DRV602 and DRV603.

There is an item of "Noise Figure" in the comparative chart of ti website below, but it is not in the data sheet.

I thought that it was the same as Noise Output Voltage, but the measurement conditions
And the value is different.

Next, I also compared the SNR but the conditions and values were different.

So please let me know the condition (measurement?) Condition of "Noise floor".

Best Regards,

Y.Hasebe

over 5 years ago

0 Ivan Salazar over 5 years ago

TI__Guru* 95165 points

Hi Hasebe-san,

I'll confirm this, but noise floor spec for these devices is most likely obtained by measuring the idle channel noise with A-Weighted filter.

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

0 yoshiki hasebe over 5 years ago in reply to Ivan Salazar

Mastermind 6385 points

Hello Ivan-san,

Thank you for your reply.
I understand your comments.

Please let me know when you find the condition (measurement?) of "Noise floor".

Best Regards,

0 Ivan Salazar over 5 years ago in reply to yoshiki hasebe

TI__Guru* 95165 points

Hasebe-san,

I confirm my previous input; this spec is obtained as explained previously on this thread.

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

0 yoshiki hasebe over 5 years ago in reply to Ivan Salazar

Mastermind 6385 points

Hello Ivan-san,

Thank you for your reply.
So I have some more questions.

The unit of the noise floor is "dbu".
Please let me know the input condition of "0 dBu" when measured by Audi Precision.
Also, what is the difference between Noise Floor and SNR?

Best Regards,
Y.Hasebe

0 Ivan Salazar over 5 years ago in reply to yoshiki hasebe

TI__Guru* 95165 points

Hasebe-san,

0 dBu corresponds to 0.775V; dBu value on the table should be taken as negative.
Noise floor is the noise present in the signal that is being measured. SNR is the difference between a desired signal level and the noise floor.

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

0 yoshiki hasebe over 5 years ago in reply to Ivan Salazar

Mastermind 6385 points

Hello Ivan-san,

Thank you for your reply.

0 dBu corresponds to 0.775V; dBu value on the table should be taken as negative.

⇒I understand.

Because 0 dBs = 0.775 V, also I think that dBu in the table should be negative.

Noise floor is the noise present in the signal that is being measured. SNR is the difference between a desired signal level and the noise floor.

⇒I understand it.

　So, do you know what condition the AudioPrecision measured on the table?

　Please let me know if you know it.

Best Regards,

Y.Hasebe

0 yoshiki hasebe over 5 years ago in reply to yoshiki hasebe

Mastermind 6385 points

Hello Ivan-san,

I have DRV 601 EVM and measured Noise floor with Audio Precision.

The results are shown below.

The value of ChB is slightly different depending on the Noise of system system.

For this reason, I confirm it with CH A.

Is this value correct?

Best Regards,

Y.Hasebe

0 Ivan Salazar over 5 years ago in reply to yoshiki hasebe

TI__Guru* 95165 points

Hasebe-san,

You should use the value in the middle of the Analog Analyzer panel, by selecting "Amplitude -> dBu". This measurement will use the selected bandwidth. If available, you can select A-weighted from the filter list like the below capture (please note that this capture was taken with nothing connected to the AP so it is not a real measurement).