DRV8802: How does DRV8802 stop the motor current?

Shinji Ueda

Expert 5440 points

Part Number: DRV8802

Hi champs,

Woudl you teach me about that DRV8802 do or do not outputs motor-current following under conditions?

xVREF pin: open

DECAY pin: Low

xENBL pin: High

In my understanding, when the DECAY pin is Low, the motor current will flow even if XVREF is OPEN, HIGH or LOW, correct?

Or how does it stop the motor current?

Regards,

Shinji Ueda

over 8 years ago

0 Rick Duncan over 8 years ago

TI__Guru** 114905 points

Hi Ueda-san,

Current flows based on the following:
nSLEEP high
nRESET high
xENBL high
xVREF voltage

If xVREF is low (0V), current should flow for the blanking time as a minimum.
If xVREF is open, current should flow for the blanking time as a minimum. After that it is hard to predict because this is a high impedance path.
If xVREF is high (3.3V), current should flow until the voltage across the sense resistor meets Equation 1 times the relative current percentage in Table 2.

0 Shinji Ueda over 8 years ago in reply to Rick Duncan

TI__Expert 5440 points

Hi Rick-san,

Thank you very much.
Could you please teach me how do I stop current flowing?

Regards,
Shinji Ueda

0 Rick Duncan over 8 years ago in reply to Shinji Ueda

TI__Guru** 114905 points

Hi Ueda-san,

To stop current in one winding set AENBL or BENBL low.
To stop current in both windings, do one of the following:
1) set both aENBL and BENBL low
2) set nRESET low
3) set nSLEEP low.

0 Shinji Ueda over 8 years ago in reply to Rick Duncan

TI__Expert 5440 points

Rick-san,

Thank you very much!

Regards,
Shinji Ueda

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DRV8802: How does DRV8802 stop the motor current?