DRV8243-Q1: Current Sensing Question

Ruixin Feng

Part Number: DRV8243-Q1
Other Parts Discussed in Thread: DRV8873

Tool/software:

Hi team,

Since DRV8243 has high-side current sensing, how it senses motor current of whole cycle? customer concerns that DRV8243 can't get motor current for whole cycle. Thanks!

Rayna

over 1 year ago

0 David Medis over 1 year ago

TI__Mastermind 19600 points

Hi Rayna,

When a device like the DRV8243-Q1 has high-side current sensing, this means that it will not be able to detect current during BRAKE (slow-decay) state.

For more information, please see the following app notes.

Current Recirculation and Decay Modes (Rev. A)

An inline current sensing circuit can be added external in between OUTx and load for current sensing throughout the whole cycle.

Best,

David

0 Ruixin Feng over 1 year ago

TI__Intellectual 2405 points

Hi David,

do you have any recommended device that has low-side current sense? Thanks!

Rayna

0 David Medis over 1 year ago in reply to Ruixin Feng

TI__Mastermind 19600 points

Hi Rayna,

Yes, many of our motor drivers have low-side current sensing.

What are some of your design requirements (voltage, RMS current, peak current, load type, etc.)?

What is the application?

Best,

David

0 Ruixin Feng over 1 year ago in reply to David Medis

TI__Intellectual 2405 points

Hi David,

we need a 30V 8A to drive brushed-motor. It seems DRV8873 is best, isn‘t it?

Rayna

0 David Medis over 1 year ago in reply to Ruixin Feng

TI__Mastermind 19600 points

Hi Rayna,

Yes, the DRV8873 would be a good fit. It is worth noting that it is capable of drawing 10A peak (for a short period of time). The thermal performance of the driver will be affected if the RMS current is too high, and the device will hit thermal shutdown.

Calculations can be made from section 8.2.1.2 Drive Current and Power Dissipation in the datasheet to estimate power dissipation and thermal performance.

Best,

David

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DRV8243-Q1: Current Sensing Question