Part Number:INA326
Hi All,
I designed EMG amplifier around INA326 instrumentational amplifier. It is soldered on a dual layer PCB board with huge ground plane. When powered up without INA circuit draws 9,5 mA and supply voltage stays as it should around 3,3 V. When powered up with INA circuit draws 19,3 mA and supply voltage drops to 2,7 V.
This is the schematic of the circuit:
I measured voltage on U4A output and it is ok. Amplifier and filters are biased to VCC/2. BAT754S are used for ESD protection.
All traces are kept short and there is also ground plane. Part of the INA layout:
I talked with my friends about this circuit and we don' t have an idea why is this happening.
I am very thankful for your help and comments about the issue.