Temperature(thermocouple) measurement using AD8220

Hi, 

I am using AD8220 for temperature measurement (using thermocouple). The circuit below is only hot junction measurement, for cold junction reference measurement I use a separate RTD 

I was testing the part @ 125 C and observed that it had stopped functioning. The amplifier was drawing about ~10mA current from my voltage reference(normal current consumption should be ~750 uA).  I use ADR4550 for 5V reference. Could it be because I am not providing the return path for the bias current of the amplifier? 

Below are some of the design details 

My input voltage from J type thermocouple is 0-18.8 mV (0-345 deg C)

Gain: 99.8 (Rg=500 Ohms) 

Differential and common mode filter before AD8220 (fdiff cut off = 7.57 Hz, fcm cut off = 159.155 Hz) 

Vref = 1 V 

Would the below circuit solve the issue ? 

Appreciate your input on this 

Thanks & Regards,

Sakthivel

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