The designer can choose the internally generated reference voltages by connecting VRB to VRBS and VRT to VRTS, or provide external reference voltages to the VRB and VRT pins. The internal reference generates 0.6 V at VRB and 2.6 V at VRT. Providing external reference voltages allows easy interface to any input signal range between GND and VDD. This also allows the system to adjust these voltages to cancel zero scale and full scale errors, or to change the input range as needed.