Figure 9-1 shows the basic connections required for operation of the INA12x. Applications with noisy or high impedance power supplies may require decoupling capacitors close to the device pins as shown. The output is referred to the output reference (REF) pin, which is normally grounded. This connection must be low-impedance to provide good common-mode rejection. A resistance of 8 Ω in series with the REF pin causes a typical device to degrade to approximately 80 dB CMR (G = 1).