Current Sense IC

QWE4562009

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Current Sense IC

If the sampling resistor is placed at the high end, there will be a large common-mode voltage that makes the sampling current inaccurate. The sampling resistor of the reference circuit in the figure is placed at the high end. Is there an error? What are the advantages and disadvantages of placing the sampling resistor at the low end?

lugl4313820

Current Sense IC If the sampling resistor is placed at the high end, there will be a large common-mode voltage that makes the sampling current inaccurate. The sampling resistor of the reference circuit in the figure is placed at the high end. Is there an error? What are the advantages and disadvantages of placing the sampling resistor at the low end? I have always wanted to make a current sampling circuit, but I don’t know where to start.

QWE4562009

lugl4313820 posted on 2023-2-3 10:23 The current detection IC puts the sampling resistor on the high side. If the sampling resistor is placed on the high side, there will be a large common-mode voltage that makes the sampling circuit...

What...

大小家伙好

The current sampling resistor is placed at the low end

Disadvantage: Unable to detect load short circuit to ground

Advantages: low common mode voltage, easy to implement

ADI has an article sharing high-side current sensing implemented with discrete solutions

ADI's High-Side Current Sensing with Wide Dynamic Range: Three Solutions

High-side current detection shared by forum users, no op amp

A forum member mentioned on the 48th floor

1. Electronic fuse, overcurrent detection;

2. Poor linearity, not recommended for large-scale current sampling

QWE4562009

Posted by Big and Small Guy on 2023-2-3 15:16 The current sampling resistor is placed at the low end. Disadvantages: Cannot detect load short circuit to ground. Advantages: Low common mode voltage, easy to implement. ADI has a document...

Disadvantage: Cannot detect load short circuit to ground?

大小家伙好

QWE4562009 posted on 2023-2-3 16:34 Disadvantages: Unable to detect load short circuit to ground? I haven't figured it out

Low-side current sampling cannot detect the short-circuit faults to ground in the following two figures

In addition, low-end current sampling will also cause ground interference.

High-side current sampling can detect short-circuit faults to ground

QWE4562009

Posted by Big and Small Guy on 2023-2-3 16:48 Low-end current sampling cannot detect the short-circuit fault to ground in the two figures below. In addition, low-end current sampling also has the problem of ground interference...

After a short circuit, the current will increase. No matter which circuit it is, how can we not detect the increase in current?