DRV8452: parameter of auto torque setting

Hello Higa-San,

ATQ_LRN_MIN_CURENT is a programmable value which you set up the the minimum current in an 8 bit register. 

Taken from the autotorque section of the user's guide:

Configure the minimum and maximum current limit values in “Loop Regulation” section. These are 8-bit integer values, 0 to 255 in decimal. Set the minimum current limit value to 48 which will be equal to (48/256) * 2 A or 375 mA. With 375 mA drive current, this stepper motor will have sufficient  torque to run with a light load without losing steps or stalling. This is the criteria for choosing the minimum current limit value in an application. Set the maximum current limit value to 192 which will be equal to (192/256) * 2A or 1.5A. A higher maximum value can be chosen if needed by the application. Auto torque will allow over driving the motor for short periods of time during transient higher load torque.

On the other hand ATQ_LRN_CONST1 is the constant generated by the parametrization portion of the auto torque learn feature. More information about this can be found in the EVM User's Guide and the device datasheet. 

Best,

Pedro Arango Ramirez

Hello Higa-San,

Your interpretation is correct, the minimum current will be set during moving. That graph shows a proper description. 

The best way to go to power saving mode is by changing the pertaining bit or waiting:

Device will go to standstill power saving mode if the EN_STSL bit is '1', and the next active edge does not come before tSTSL_DLY expires. 

Best,

Pedro Arango Ramirez