# DRV8833 Dual Motor Driver Carrier-Input and Output voltage

Hi,

I intend to use DRV8833 Dual Motor Driver Carrier to drive Maxon A-max 19 DC brushed motor of 2.4V nominal voltage and 2A peak current.

(1) Can I use analog input for AIN1 and AIN2 as the reference input to drive the motor? (The voltage of the signal input can be varied between ±10V)

(2) If I supply VIN with 5V, how do the AOUT1 and AOUT2 function according to AIN1 and AIN2? I understand that for DRV8833 the input high voltage for the logic pin is minimum 2V, if I supply AIN1 with 2V and AIN2 grounded, does that mean i will get AOUT1 = 2V and AOUT2= 0V?

p.s: I am new to H-bridge and motor driver.

Thanks,
CK

Hello, CK.

No, those pins are digital inputs with a recommended maximum voltage range of -0.3 to 5.75 V.

The truth table on page 8 of the datasheet explains how the driver inputs affect the outputs. Basically, you can use the inputs to turn the outputs on or off. When the are on, the full motor supply voltage, VIN, is output in the direction corresponding with the inputs. You can control the motor speed by rapidly turning the outputs on and off, which is usually accomplished by supplying a PWM signal to the inputs. For example, if you hold AIN1 low and alternate between driving AIN2 high for 25 us and low for 25 us, you are effectively supplying the motor with half the VIN voltage. The percentage of the PWM cycle that the outputs are active is called the “duty cycle”, and the output voltage will effectively be the duty cycle * VIN.

You might this wikipedia article on H-bridges helpful in understanding how this driver works.

- Ben

Hi Ben,

I am actually looking for a driver for my Maxon motor running on 2.4V nominal voltage and 1A cont. current.
It is hard to find a driver for low voltage motors but I managed to find Pololu item #120 “Pololu Low-Voltage Dual Serial Motor Controller” in the discontinued products but it only takes in serial signal.

I think the only suitable product here I can use is the Sanyo LB1836M Motor Driver (Pololu Item # 399). However, there is no sample circuit in the spec sheet which I can refer to. Can you kindly enlighten me about setting up the driver circuit?

Any other product that you think will be suitable for my application?

Thanks
CK

Do you know the stall current of your motor?

- Ben

Hi,

It is 2.09A for starting current.

Is that a manufacturer’s spec or something you measured? If it’s the latter, how did you measure it? I generally would expect the stall current to be much more than the continuous current, unless you are operating the motor with a heavy load. How many motors are you trying to drive?

- Ben

It is obtained from the Maxon spec sheet A-max 19, I am trying to drive 8 motors for robotic applications.

So just to be clear, by “A-max 19”, are you saying that the stall (maximum) current is 19 A? And is that spec at 2.4 V?

- Ben

Sorry for the confusion, Amax-19 is the Model No. Please refer to the spec http://www.aviton.spb.ru/files/doc/pdf/maxon/094.pdf
Second column with 2.4 V nominal voltage and 2.09A starting current.

I still recommend you use the DRV8833 driver. The maximum continuous current for your motors is within the range of what the DVR8833 can deliver continuously, and the stall current is within the peak rating for the driver as well.

The DRV8833 will not operate at 2.4 V, but it is generally ok to operate DC motors over a range of voltages. I expect your motor to be fine at a higher voltage (e.g. 3.7 V), but if you are concerned about it, you could always use a higher voltage and just limit your maximum duty cycle so the motor never sees more than 2.4 V on average.

- Ben

I see, thank you so much Ben.
I will try to limit the current then.

CK