The LM3822 Current Gauge provides easy to use precision current measurement with virtually zero insertion loss (typically 0.003Ω). The LM3822 is used for high-side sensing.
A Delta Sigma analog to digital converter is incorporated to precisely measure the current and to provide a current averaging function. Current is averaged over 50 msec time periods in order to provide immunity to current spikes. The ICs have a pulse-width modulated (PWM) output which indicates the current magnitude and direction. The shutdown pin can be used to inhibit false triggering during start up, or to enter a low quiescent current mode.
The LM3822 is factory-set in two different current options. The sense range is −1.0A to +1.0A or −2.0A to +2.0A. The sampling interval for this part is 50ms. If faster sampling is desired, please refer to the data sheet for the part number LM3824.
• No External Sense Element Required
• PWM Output Indicates the Current Magnitude
• PWM Output is Easily Interfaced with
Microprocessors and Controllers
• Precision ΔΣ Current-Sense Technique
• Low Temperature Sensitivity
• Internal Filtering Rejects False Trips
• Internal Power-On-Reset (POR)
• DC Offset is Less than 1 mA for 1A Part
• Battery Charge/Discharge Gauge
• Motion Control Diagnostics
• Power Supply Load Monitoring and
• Resettable Smart Fuse
• Ultra Low Insertion Loss (Typically 0.003Ω)
• 2V to 5.5V Supply Range
• ±2% Accuracy at Room Temperature for the 1A
Device (Includes Accuracy of the Internal
• Low Quiescent Current in Shutdown Mode
(Typically 1.8 µA)
• 50 msec Sampling Interval
• In MSOP-8 Package
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