LM3813

·No external sense element required
· PWM output indicates the current magnitude and direction
· PWM output can be interfaced with microprocessors
· Precision DS current-sense technique
· Low temperature sensitivity
· Internal filtering rejects false trips
·Internal Power-On-Reset (POR)

The LM3812/LM3813 Current Gauges provide easy to use precision current measurement with virtually zero insertion
loss (typically 0.004W). The LM3812 is used for high-side sensing and the LM3813 is used for low-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 LM3812 and LM3813 are factory-set in two different current options. The sense range is −1A to +1A or −7A to +7A. The sampling interval for these parts is 50ms. If faster sampling is desired, please refer to the data sheets for the part numbers LM3814 and LM3815.