Two methods for measuring current and what sense amplifier used are tackled in this app note from Texas Instruments. Link here (PDF)
Current is a signal that can provide valuable insight into how a system is operating. Under defined conditions, the amount of current required to perform a task is consistent, making the current information a useful indicator to determine if the system is operating within expectations. There are multiple measurement methods and locations where current is measured to evaluate this informative signal.
Another TS1001 op-amp application from Silicon Labs on sensing nano currents. Link here (PDF)
Current-sense amplifiers can monitor battery or solar cell currents, and are useful to estimate power capacity and remaining life. However, if the battery or solar source is a single cell, it’s difficult to find a low voltage solution that works below 1V and draws just microamps. A new class of nanopower analog ICs, namely the TS1001 0.8 V/0.6 µA op amp, makes a sub-1 V supply current sense amplifier possible. This discrete circuit operates from as low as 0.8 V and draws 860 nA at no load while providing a 0–500 mV output for measured currents of 0–100 mA, though the scale can be adjusted by changing the values of a few resistors. With its extremely low power, the circuit can simply remain “always on,” providing a continuously monitored, averaged indication of current which can subsequently be read periodically by a microcontroller, without causing too much current drain in the battery.
App note from STMicroelectronics about current sensing using Rogowski coil together with STPMxx metering device. Link here (PDF)
This application note describes the benefits of a current sensing system for metering applications using STPMxx metering devices and a current sensor developed by Pulse Engineering Inc. (hereafter referred to as “Pulse current sensor”), based on the Rogowski coil principle. Following an overview of the Rogowski coil principle, the Pulse current sensor is introduced along with a comparison to other current measuring devices. This is followed by a presentation of the characteristics of the STPMxx family of metering devices, and the results of accuracy testing conducted using a demonstration board with the STPM01 and the Pulse current sensor.
Application note from STMicroelectronics for fine tuning gain on current sensing amplifier. Link here (PDF)
This application note explains how to use current sensing amplifiers with series resistors on the sense inputs. This approach is especially useful for applications where the gain must be adjusted.
Silicon Lab’s TS1100 and TS1101 current sense amplifier’s features discussed in this app note. Link here (PDF)
Sensing and controlling supply current flow are a fundamental requirement in most all electronic systems from battery-operated, portable equipment to mobile or fixed-platform power management and dc motor control. High-side current-sense amplifiers (or “CSAs”) are useful in these applications especially where power consumption is an important design parameter. New CSA developments offer even greater benefits in allowing engineers to save power without sacrificing performance.