LM3822 Datasheet | National Semiconductor

Description 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. Key Specifications n Ultra low insertion loss (typically 0.003Ω) n 2V to 5.5V supply range n ± 2% accuracy at room temperature for the 1A device (includes accuracy of the internal sense element) n Low quiescent current in shutdown mode (typically 1.8 µA) n 50 msec sampling interval n In MSOP-8 Package Features n No external sense element required n PWM output indicates the current magnitude and direction n PWM output is easily interfaced with microprocessors and controllers n Precision ∆Σ current-sense technique n Low temperature sensitivity n Internal filtering rejects false trips n Internal Power-On-Reset (POR) n DC Offset is less than 1 m A for 1A part Applications n n n n Battery charge/discharge gauge Motion control diagnostics Power supply load monitoring and management Resettable smart fuse Connection Diagram DS101249-1 Top View LM3822 for High-Side Sensing © 2000 National Semiconductor Corporation DS101249 .national. Ordering Information Order No.- LM3822MM-1.0 LM3822MMX-1.0 LM3822MM-2.0 LM3822MMX-2.0 Sense Range Sampling Interval- 50 ms 50 ms 50 ms 50 ms Sensing Method...