DRV8323: The output impedance of current sense amplifier's output pin

Kazuki Kuramochi

Part Number: DRV8323

Hello Professional,

My customer is evaluating DRV8323S and the has question for the specification of SOA, SOB and SOC pins.

Customer would like to know about output impedance of these pins. This is because, they want to use this specification for estimating the ADC's sample rate.
Is it possible to provide for us?

Best regards,
Kuramochi Kazuki

over 4 years ago

0 Adam Sidelsky over 4 years ago

TI__Guru 61380 points

Kuramochi-San,

Thanks for posting on our Motor Drives Forum!

If you are asking about the resistance of R6 as mentioned in the datasheet, this is in fact not real and we will be removing it from the diagram.

Regards,

-Adam

0 Kazuki Kuramochi over 4 years ago in reply to Adam Sidelsky

TI__Expert 8370 points

Hello Adam-san,

Thank you for your prompt reply.

I understand about figure.35 on datasheet p43 is not actual circuit.
Well, Could you provide internal current sens AMP's output impedance or Load regulation curve?

Best regards,
Kazuki Kuramochi

0 Adam Sidelsky over 4 years ago in reply to Kazuki Kuramochi

TI__Guru 61380 points

Kuramochi-San,

I need to check with design and will get back to you this week.

Regards,

-Adam

0 Kazuki Kuramochi over 4 years ago in reply to Adam Sidelsky

TI__Expert 8370 points

Adam-san,

Sorry for rushing you.
But could you provide update for this topic?

Best regards,
Kazuki Kuramochi

0 Adam Sidelsky over 4 years ago in reply to Kazuki Kuramochi

TI__Guru 61380 points

Kuramochi-San,

The output impedance is hard to specify exactly. If you need a specific answer for your case then please show us the schematic and ADC parameters including the sampling rate.

As long as the ADC input capacitance is less than 60pF and there is no major external output filter then the 1MHz datasheet spec should be valid.

Regards,

-Adam

0 Kazuki Kuramochi over 4 years ago in reply to Adam Sidelsky

TI__Expert 8370 points

Adam-san,

Thank you for your support.

I will ask customer to provide some data as you requested.
By the way, customer will accept load regulation curve instead of output impedance. Is this possible to provide?

Best regards,
Kazuki Kuramochi

0 Kazuki Kuramochi over 4 years ago in reply to Kazuki Kuramochi

TI__Expert 8370 points

Adam-san,

Sorry for rushing you.
Would you provide answer for capturing load regulation curve of DRV8323's current sense amp.

Best regards,
Kazuki Kuramochi

0 Adam Sidelsky over 4 years ago in reply to Kazuki Kuramochi

TI__Guru 61380 points

Kuramochi-San,

We do not have a load regulation curve to share unfortunately.

Regards,

-Adam

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DRV8323: The output impedance of current sense amplifier's output pin