Driven by the booming development of electric vehicles and industrial automation, we have seen an increase in the number of high-voltage and AC connected electronic devices used to monitor system performance. Usually can be usedcurrent sensor To meet this requirement, the current sensor is used for measuring the system and subsequently controlling the system.However, in modern timescurrent sensor There is still a certain trade-off between cost, accuracy, and isolation - engineers make a series of difficult decisions when choosing the most practical equipment for their design.

There are many different configurations of current sensors, but they can all be classified into two forms: open-loop and closed-loop. Both of these configurations depend on the manipulation of the magnetic field, particularly utilizing the Hall effect (hence referred to asHall Effect Sensor ）.

Open-loop sensorUsually composed of Hall sensors placed in the gap between magnetic cores. The required current will generate a magnetic field, which is concentrated by the iron core and measured by a Hall sensor. These sensors are very cheap, but lack accuracy.

One of the main reasons for inaccurate open-loop sensors is drift. Drift can be thermal drift or time drift. Thermal drift refers to changes in the normal operating behavior of a device caused by changes in ambient temperature, while time drift refers to changes in behavior caused by age-related changes in the device.

On the other hand, closed-loop sensors utilize feedback networks with high loop gain to prevent errors caused by device changes (i.e. thermal drift). They have fast response, high linearity, and high resistance to electrical noise, but are relatively expensive in price. Due to these reasons, it is often requestedhigh-precisionChoose closed-loop sensors in the application.

Engineers can mitigate the impact of drift in open-loop sensors to achieve high precision and low costcurrent sensor . Some technologies are currently being used.

One of these technologies is the use of a current sensing amplifier that integrates a precisely matched resistive gain network, which minimizes the temperature drift effect of gain error.

Nowadays, there are many demands for monitoring and controlling electrical systems of current measuring equipment, hoping to prevent faults. Having more accurate Hall effect current sensors like the new Texas InstrumentsOpen-loop sensorIt will be possible to detect smaller levels of performance changes, thereby gaining a deeper understanding of system performance.

This message greatly improves the accuracy of current detection and is expected to help improve system performance, protection, and cost in the future