DRV8837C: Why OUT1 is the opposite of OUT2 when PWM is on IN1 and IN 2 to ground?

Hi Bitou,

Would you please resend your graph? It did not appear.

I copy/paste the image, it shows on my computer

I use Insert Media for the below image:

Hi Bitou,

Thank you for resending the image.

I am assuming you are asking why the OUT1/OUT2 do not enter the Z state when the PWM input is 0. Is that correct?

When IN1 transitions from 1 to 0, the outputs will be disabled as shown in Table 1. But if there is current flowing through the inductive load, the voltage on the outputs will switch from VCC to -0.7V or from GND to VCC+0.7V. This voltage is needed to maintain current flow through the load.

Once the current drops to zero, the two outputs may change.

Thanks for your answer

> I am assuming you are asking why the OUT1/OUT2 do not enter the Z state when the PWM input is 0. Is that correct?

Yes

> When IN1 transitions from 1 to 0, the outputs will be disabled as shown in Table 1. But if there is current flowing through the inductive load, the voltage on the outputs will switch from VCC to -0.7V or from GND to VCC+0.7V. This voltage is needed to maintain current flow through the load.

Ok great I understand the behaviour

I asked that question because in the datasheet, the plots shows no PWM signal on OUT2 (Figure 7) and it seems that there is load (OUT2_I). Why is it different on datasheet graphs?

Regards,

Thank you for the details! We divided by two our power consumption.
It was not clear in the datasheet but we understand now

Regards,