设置
快速交货
免运费
国际贸易术语
支付类型
市场产品
To conclude on this overall comparison between the magnetic-based and shunt-based current sensing, one can expect to have: A much smaller PCB footprint thanks to a an all-integrated magnetic solution which does not need further external circuitry. The overall footprint of the ACS71240 in the 3 x 3 mm2 QFN package is three times smaller than the discrete version of it. Thanks to this level of integration, the designers have less to worry about. Significant signal chain design effort is needed with shunt-based solutions in order to reach a good accuracy and resolution. For example, there needs to be some filtering to compensate for the change in impedance from the change in frequency. The shunt resistance also varies across temperature and can have a big impact on the accuracy. Furthermore, dimensioning the shunt is not easy in order to have a good compromise between SNR and power consumption. To have a low power consumption, the shunt resistances are becoming voluminous and expensive if they are precise. However, going with a lower resistance value also gives a lower output voltage that needs to be amplified, making the SNR worse. So, the higher the resistance value, the higher the chances of having a high output value with good SNR. It is a balancing act. Lastly, when an in-phase or high-side measurement is needed, shunt-based solutions require a discrete isolation stage. Indeed, to withstand high voltages above their rail and send the shunt measurement to the microcontroller, expensive, voluminous and complicated analog or digital isolation circuits must be designed. Some Current Sensor Amplifiers can have an integrated isolation that withstands common-mode voltages that hardly go above 100 V. This means that an independent isolation stage is usually necessary with shunt-based solutions for working voltages above 100 V, while Hall-Effect and GMR sensors have intrinsic galvanic isolation that only magnetic sensing can provide. Their isolation level can go up to 5 kVRMS, or even more in the case of hall-effect field (also called ambient) sensors.
