LMC6582AIMX NSC [National Semiconductor], LMC6582AIMX Datasheet - Page 16

• Manufacturer Part Number: LMC6582AIMX
• Description: Low Voltage, Rail-To-Rail Input and Output CMOS Operational Amplifier
• Manufacturer: NSC [National Semiconductor]

Battery Monitoring Circuit
The LMC6582/4 has been optimized for performance at 3V,
(Continued)
and also has guaranteed specs at 1.8V and 2.2V. In portable
applications, the R
represents the laptop/notebook, or
Load
any other computer which the battery is powering. A desired
output voltage can be achieved by manipulating the ratios of
the feedback resistors. During the charging cycle, the cur-
rent flows out of the battery as shown. While during dis-
charge, the current is in the reverse direction. Since the cur-
rent can range from a few milliamperes to amperes, the
amplifier will have to sense a signal below ground during the
discharge cycle. At 3V, the LMC6582/4 can accept a signal
up to 300 mV below ground. The common-mode voltage
range of the LMC6582/4, which extends beyond both rails is
thus a very useful feature in this application.
DS012041-34
A typical offset voltage of 0.5 mV, and CMRR of 82 dB main-
FIGURE 24. Circuit used to Sense Discharging
tain accuracy in the circuit outputs while the rail-to-rail output
performance allows for a maximum signal range.
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