hi, there is a customer who used AD8304 in optical power meter(following the figuration 7 in the datasheet). he found that when the current is below 100uA, the VPDB is alway 0.6V no matter how samll the current is. when he increases the optical power, the VPDB is slightly increase. this is different with the bias voltage(0.1V~2V) which is described in the datasheet. he thinks the linearity of the current below 100uA is too bad. could you give some suggestion? thanks.