Tool/software:
Hello team,
INA849's Input bias current max value is specified with positive number (20nA). Its distribution data (figure 7-5 and 7-6) also shows input bias current is in only positive side.
What is direction of the input bias current? Is it sink direction or source direction?
I am curious if the direction can be either because it looks INA849 has Ib cancelation internally. So I wanted to confirm with you just in case.
Best regards,
Hello Sato-san,
Typically, bias current is specified to be positive when it flows into the pin of the device, and negative when flowing out of the pin of the device. The direction of the input bias current will be into the device in this case. You are correct that in many cases with bias current cancellation, current can be in or out of the pin, however, in the case of the INA849, a non-zero mean looks to be targeted.
The mean bias current value is roughly 7nA, with a max input offset current specified to be 6nA. This means that the bias current should be into the device, but I am confirming internally to see that this will consistently be the case.
Best,
Gerasimos
