A shunt resistor (R_SHUNT) is an accurate resistance inserted in series with the load as shown in Figure 9-6. If the absolute voltage drop across the shunt, |V_SHUNT|, is a larger percentage of the bus voltage, the voltage drop can reduce the overall efficiency and system performance. If |V_SHUNT| is too low, measuring the small voltage drop requires careful design attention and proper selection of the ADC, operation amplifier, and precision resistors. Make sure that the absolute voltage at the shunt terminals does not result in violation of the input common-mode voltage range requirements of the operational amplifier. The power dissipation on the shunt resistor increases the temperature because of the current flowing through the resistor. To minimize the measurement errors resulting from variation in temperature, select a low-drift shunt resistor. To minimize the measurement gain error, select a shunt resistor with low tolerance value. To remove the errors caused by stray ground resistance, use a four-wire Kelvin-connected shunt resistor, as shown in Figure 9-6.