AN1949| Application Note
Maxim/Dallas > App Notes > AMPLIFIER AND COMPARATOR CIRCUITS BATTERY MANAGEMENT
AUTOMOTIVE
Keywords: bidirectional, current sense amp, current monitor, battery, charge current, discharge current, amplifier, amplifiers, amps
Mar 25, 2003
APPLICATION NOTE 1949
Bi-directional Current-Sense with Single Output
Battery operated devices often need to monitor both charge and discharge currents. A dual current-sense amplifier and differential amplifier are combined to produce a single output voltage that indicates magnitude and direction of battery current. Systems such as laptop computers and other devices that have internal charge circuitry require a precise bidirectional current-sense amplifier to monitor accurately the battery's current regardless of polarity. The MAX4377 (a dual low-cost current-sense) can be used to produce a bi-directional current monitor.
Figure 1. Output voltage OUT_ is proportional to the magnitude of the sense voltage (VRS+ - VRS-). OUT_ is approximately zero when VRS- > VRS+. When VRS+ > VRS-, VOUT = (GAIN)(RSENSE)(ILOAD) where GAIN = 20 for MAX4377T.
AN1949 Application Note maxim Download PDF
Add this permalink to your bookmarks for future download of AN1949 ApplicationNote
Permalink: http://application.emcelettronica.com/maxim/AN1949
