BDC Motor Current Sense Amplifier Using Old Op-Amp and Comparator

Alhvarez Gohtoosh

Other Parts Discussed in Thread: LM324, LM393, LM339, LM358, INA219, DRV8876, DRV8874, DRV8873

I like to Drive a Brushed DC motor. This is my motor

I intend to design a low side (or High side if is not possible) shunt based current amplifier circuit.
Problem is i have to to use combination of old Op-Amps and Comparators like: LM324,LM358,LM393,LM339,etc
I know about benefits of new current shunt amplifiers like ina219 and similar parts and newly design zero drift op-amps. but i limited to use these parts.can anyone help to say which one of these parts can i use or maybe share a schematic. thanks

over 2 years ago

0 Ryan Kehr over 2 years ago

TI__Guru 55615 points

Hello,

This design can be greatly simplified and not require and external sensing element or amplifier using an integrated motor driver.

DRV8876

DRV8874

DRV8873

DRV8243

DRV8244

DRV8245

Those are in order of power capability. DRV8876 being the lowest power and DRV8245 the highest power option. All have integrated current sense and iPropi for monitoring the current. See app note below:

https://www.ti.com/lit/an/slvae68b/slvae68b.pdf

Regards,

Ryan

0 Alhvarez Gohtoosh over 2 years ago in reply to Ryan Kehr

Prodigy 20 points

Thank you. i'm looking for another solution other than using driver IC's for many reasons.

0 Ryan Kehr over 2 years ago in reply to Alhvarez Gohtoosh

TI__Guru 55615 points

Hello,

I am going to pull in our amplifier specialists to help you.

Regards,

Ryan

0 Gerasimos Madalvanos over 2 years ago in reply to Ryan Kehr

TI__Mastermind 33011 points

Hey Alhvarez,

LM358 works excellently for low-side current sense, with an input common mode range to V- and an output stage designed to get close to the negative rail (with light loads). You can read more on the output stage in the following application note.

https://www.ti.com/lit/an/sloa277a/sloa277a.pdf

Best,
Jerry

0 Alhvarez Gohtoosh over 2 years ago in reply to Ryan Kehr

Prodigy 20 points

Thanks man

Motor drivers

Motor drivers forum

BDC Motor Current Sense Amplifier Using Old Op-Amp and Comparator