Current sensing amplifiers measure current by outputting a voltage that is proportional to the flowing power current. A resistor is used to convert the load current to a small voltage which is then accurately amplified. They offer real-time overcurrent protection.
Accurate current sensing is crucial to optimising performance in a range of applications, such as motor control and power management. In devices where battery or power-line monitoring is highly necessary, like laptops and phones, current sensing amplifiers are critical.
There are several factors that will determine the the type of amplifier you choose, including whether the measurement will be on the high or low side. The sense resistor can be placed either between the supply voltage and load, or between the load and ground. The former is called high-side seinsing, whereas the latter is called low-side sensing. High voltage current sensing amplifiers offer input ranges up to +76V and down to -20V, ideal for applications such as motor control and network routers. Low power current sensing amplifiers help to maximise and extend battery life.