The load current (ILOAD) produces a voltage drop across the shunt resistor (RSHUNT). The load current is set from 0 A to 1 A. To keep the shunt voltage below 100 mV at maximum load current, the largest shunt resistor is defined using Equation 2.
Using Equation 2, RSHUNT is 100 mΩ. The voltage drop produced by ILOAD and RSHUNT is amplified by the TSV91x to produce an output voltage of approximately 0 V to 4.95 V. The gain required by the TSV91x to produce the necessary output voltage is calculated using Equation 3:
Using Equation 3, the required gain is calculated to be 49.5 V/V, which is set with resistors RF and RG. Equation 4 is used to size the resistors, RF and RG, to set the gain of the TSV91x to 49.5 V/V.