[ DRV8303 ] Not to use integrated current shunt amp

Kenichiro

[ DRV8303 ] Not to use integrated current shunt amp

Hi Expert,

My customer does not intend to use the integrated current shun amplifiers, since they already have some sort of proven motor control schemes with external current sensor. Can you help me to figure out how unused related pins should be?

Pins	When unused...
SN1/SN2 (input of current amp, negative)	???
SP1/SP2 (input of current amp, positive)	???
REF (ref voltage to set output of shunt amp)	???
SO1/SO2 (output of current amp)	???

Thank you for your support in advance.

Regards,

Ken

over 9 years ago

0 Wilson Zuo over 9 years ago

TI__Mastermind 26065 points

Hi Ken,

The goal is to set the amp into a stable unused state. The simplest way I think is just to connect SPx SNx together to the GND and SOx floating, REF to a 3.3V voltage.

Best regards,

0 Kenichiro over 9 years ago in reply to Wilson Zuo

Mastermind 9165 points

Hi Wilson,

Thank you for your reply!

Do you recommend to connect REF to 3.3V rail? Since customer has 5V supply for VDD_SPI, connecting to 5V should be more preferable.

Pins
SP1/SN1 SP2/SN2	Connect together to GND
REF
SOx	can be left floating

Thanks,

Ken

0 Nicholas Oborny over 9 years ago

TI__Mastermind 21320 points

Hi Ken,

Wilson's suggestion will work. There is also a slightly more optimal way to connect them to reduce power consumption slightly.

Each op amp should be connected in unity gain configuration.

SN1 = SO1

SN2 = SO2

SP1/SP2 = GND

REF = Supply Rail (5 V is OK)

SO1 = SN1

SO2 = SN2

0 Kenichiro over 9 years ago in reply to Nicholas Oborny

Mastermind 9165 points

Hi Wilson, Nicholas,

Thank you for your reply! I have suggested your ideas to customer.

Thanks,
Ken

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[ DRV8303 ] Not to use integrated current shunt amp

[ DRV8303 ] Not to use integrated current shunt amp