TMS320F28377D: The problem obout SDFM_TO_SHUNT in the controlsuit example IDDK_PM_Servo_F2837x_v2 project

shook xu

Part Number: TMS320F28377D
Other Parts Discussed in Thread: AMC1304M25

hi ！

in controlsuit the example project IDDK_PM_Servo_F2837x_v2, when i used the sdfm to sample the motor current, I have some question about the conversion coefficient show in the follow picture

why the sdfm is 0.8906pu current is 12.5A, the sample resistance is 20mohm, the delta-sigma (ΔΣ) modulator is AMC1304M25, in the datasheet of AMC1304M25 the Specified linear full-scale range is -250mv to 250mv, the Maximum differential voltage input range is -312.5mv to 312.5mv.

why the sdfm is 0.8906pu current is 12.5A?

thank you!

over 5 years ago

0 shook xu over 5 years ago

Intellectual 745 points

Anybody give me some suggestion, thank you!

0 Ramesh Ramamoorthy over 5 years ago in reply to shook xu

TI__Mastermind 27240 points

The answer lies in your question, the system is designed for the specified linear range of 250mV. Between 250mv and 312.5mV, it is non-linear and to be able to use that range, some post processing based on a LUT or other emperical method may be needed, which is time consuming and is not attempted here.

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TMS320F28377D: The problem obout SDFM_TO_SHUNT in the controlsuit example IDDK_PM_Servo_F2837x_v2 project