LM3824

LM3824 Precision Current Gauge IC with Internal Zero Ohm Sense Element and PWM Output July 2000 LM3824 Precision Current Gauge IC with Internal Zero Ohm Sense Element and PWM Output General Description The LM3824 Current Gauge provides easy to use precision current measurement with virtually zero insertion loss (typically 0.003Ω). The LM3824 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 6 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 LM3824 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 6ms. If a more precise measurement is required, please refer to LM3822 datasheet. Key Specifications n Ultra low insertion loss (0.003Ω) n 2V to 5.5V supply range n ± 3% 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 6 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 mic...