SPRUHJ1I January 2013 – October 2021 TMS320F2802-Q1 , TMS320F28026-Q1 , TMS320F28026F , TMS320F28027-Q1 , TMS320F28027F , TMS320F28027F-Q1 , TMS320F28052-Q1 , TMS320F28052F , TMS320F28052F-Q1 , TMS320F28052M , TMS320F28052M-Q1 , TMS320F28054-Q1 , TMS320F28054F , TMS320F28054F-Q1 , TMS320F28054M , TMS320F28054M-Q1 , TMS320F2806-Q1 , TMS320F28062-Q1 , TMS320F28062F , TMS320F28062F-Q1 , TMS320F28068F , TMS320F28068M , TMS320F28069-Q1 , TMS320F28069F , TMS320F28069F-Q1 , TMS320F28069M , TMS320F28069M-Q1
Resistor shunt current measurement is a very reasonable technique for measuring current in a motor control inverter. There are three widely used examples, the 1-Shunt, 2-Shunt, and 3-Shunt resistor measurements. While at first the 1-Shunt and 2-Shunt techniques seem to be saving money, they require much faster and more expensive amplifier circuits (see Table 18-3). 1 and 2 Shunt current measurements also limit the capability of the current feedback which will limit the ability of the drive to use the full voltage that is provided to the inverter. The 3-Shunt technique is superior and not much different in cost due to the advantage of using cheap, slow, current amplifier circuits.
Shunts | Op-Amp Slew Rate |
---|---|
1 | >20 V/µs |
2 | >6 V/µs |
3 | >1 V/µs |