Input bias current

6145095

Part Number: INA233
Other Parts Discussed in Thread: INA190, INA186, INA239-Q1, INA229-Q1, INA237-Q1, INA238-Q1, INA228-Q1

I'm using the INA233 to measure current in the range of 0 to 500uA. When I request the current reading, is the input bias current taken into account?

I noticed when the common mode bias voltage is 4 to 4.5V, the input bias current is around 13uA.

Is there a functional and footprint compatible part with lower input bias current?

over 3 years ago

0 kai klaas69 over 3 years ago

Guru 140200 points

Hi,

have you looked here?

Kai

0 Peter Iliya over 3 years ago

TI__Mastermind 26780 points

Hello and welcome to the forum,

The INA233 does not take into account it input bias current when measuring micro-Amps of current. The 13uA of current will appear as an offset of Rshunt*IB at the input.

If you want a digital device that has a higher input impedance (lower IB), then you could consider the INA229-Q1 or INA239-Q1. The INA190/INA186 are also low-IB current sense amplifiers.

Hope this helps.

Best,

Peter

0 6145095 over 3 years ago in reply to Peter Iliya

Prodigy 105 points

Thank you Peter,

That's very helpful. Does TI plan to make digital power monitor devices with lower IB(~5nA), with I2C interface in the future?

0 Peter Iliya over 3 years ago in reply to 6145095

TI__Mastermind 26780 points

Hello again,

Unfortunately, I cannot say for certain there will be a release of this product soon.

Best,

Peter

0 DHarmon over 3 years ago in reply to 6145095

TI__Genius 16080 points

Please check out the INA228-Q1, INA238-Q1, and INA237-Q1. These devices are now in preview mode on ti.com. They are I2C output devices and per the spec table have 5nA max IBIAS

0 6145095 over 3 years ago in reply to DHarmon

Prodigy 105 points

Thank you Mr. Harmon. They're exactly what I'm looking for!

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Input bias current