App note: Circuits and principles of high side current measurement
Maxim describes several high side current measurement circuits:
This entry was posted in app notes and tagged app note, maxim.This application note describes the use of current sense amplifiers, differential amplifiers and instrumentation amplifiers to measure battery charge and discharge currents in portable equipment, computer notebooks and USB accessories. It compares high side current sense amplifiers with low side differential amplifiers and recommends selection criteria for current sense resistors. A high voltage circuit breaker circuit is described to provide system over current protection due to faults and short circuits. Application circuits for a variable linear current source and a programmable 0-5A current source is included.
Comments
This app note totally ignores the magnetic current sensors that other companies make. Like the sense resistor, it can be internal or external to the IC that does the rest of the current measurement.
Chip companies like to sell their own stuff and I don’t think Maxim makes
any Hall effect sensors. Another good ap note in this field is LT AN105,
“Current Sense Circuit Collection”.
http://www.linear.com/docs/12479
I’ve used the Tamura Hall effect sensors but they cost a lot more than
a resistor and op-amp. The 25A one we used is over $10 in production
quantity.