OPA838: Unexpected Large Offset Voltage

Part Number:OPA838

Hi,

I'm using TI's op-amps (OPA838 7V/V + TLV3541 1.3V/V) as two-stage amplifier for a current signal. The schematic is shown as following. The amplified signal goes to a MAX comparator.

However, during the hardware test, we notice there's an unexpected 30mV offset at the OPA838 input set which is much larger than datasheet value (worst case <300uV). The offset makes this zero-current detection very bad. Could anyone help me to see what's wrong here?

Best,

Patrick