I bought some pieces of differential amplifier AD629 one month ago. I soldered AD629 on the pcb board I designed. But I can not get desired output voltage level. I connect a DC voltage to the input two pins of AD629 with "+" connected to pin 3, "-"connected to pin 2. Pin 1, 4, 5 are all connected to ground based on the description of datasheet. The voltage supply of the chip is 15V. The voltage supply is connected with a 0.1uF capacitor to the ground. I set the input voltage to 3V. But the output from pin 6 is 1.48V. Even when I remove the input voltage or short circuited the input voltage, the output still showed 1.48V. I donot know what to do. Is there anything wrong with the chip or the design of my board.
Below is my schematic.