The input circuitry of the INA139 can accurately measure beyond its power-supply voltage, V+. For example, the V+ power supply can be 5 V, whereas the load power supply voltage is up to 40 V (or 60 V with the INA169). However, the output voltage range of the OUT terminal is limited by the lesser of the two voltages (see Output Voltage Range). TI recommends placing a 0.1-µF capacitor near the V+ pin on the INA139 or INA169. Additional capacitance may be required for applications with noisy supply voltages.