INA188 bias current vs Temperature curve

Hi,

 How to understand input bias current value when temperature is below 75C in following curve? what means for "0" and "-2000" on curve? Tks. 

Regards,

Eric  

Amy Luo：

您好
您可以参考链接：e2echina.ti.com/…/18865

Xiaobing (Eric)：

回复 Amy Luo:

Tks for your feedback, Amy, but you did not answer the questions. Can you help to confirm INA188 Amplifier datasheet page 10 curve 10, what's means "0" and "-2000" means on the vertical scale of the in put bias current VS temperature curve? Look forward your feedback, tks. 

Regards,

Eric

Kailyn Chen：

The negative means the current flow out of the device, and if it is positive then current flows into the device.

If the data sheet IIB value shows positive and negative values then the op-amp has bias current cancellation circuitry and the current will be small but the polarity may be either.

PNP input devices have a negative IIB (current flows out of inputs)NPN input devices have a positive IIB (current flows in to inputs)

Xiaobing (Eric)：

回复 Kailyn Chen:

Tks for your answer, Kailyn.
Refer above curve input bias current VS temperature curve (INA188), how is bias current during temperature below 75C, 65C or smaller?Can you explain it how to get it on the curve? Tks.

Regards,

Eric

Amy Luo：

回复 Xiaobing (Eric):

Hi Eric
Input bias current (IIB) of FET OP amplifier is generally composed of two parts, one is the leakage current of ESD protection diodes, and the other is the grid current of the FET. When the temperature is higher, the leakage current takes up the main part. And under relatively low temperatures, the grid current is the main part. So the IIB value has positive and negative.
We can only get an approximate IIB value from the above curve. If you need an exact valve you can refer to the following link for details: e2echina.ti.com/…/360202
I hope this information will be useful.
Regards,
Amy

Xiaobing (Eric)：

回复 Amy Luo:

Amy,
easy way, refer above curve of input bias current VS temperature, (INA188), pls confirm how is bias current value when temperature at 75 C? Tks.

Regards,

Eric

Amy Luo：

回复 Xiaobing (Eric):

Hi Eric

I am sorry that there is no information about exact IIB value under the exact temperature. If you need all the data in the curve you can test it in high temperature chamber. Hope that can help you.

Regards,
Amy

Xiaobing (Eric)：

回复 Amy Luo:

Amy,
Tks for your info. Maybe make you confuse, I don't need exact Iib value, just need reference Iib value from curve at 75C, can you help to confirm it?
Regards,

Eric

Amy Luo：

回复 Xiaobing (Eric):

I am sorry for reply later.

Since the IIB valve at 75℃ is similar as at the temperature25℃, so you can reference the IIB valve at temp 25.
Another method is to use TINA-TI software to measure with the temp setting at 75℃.

Best Regards,

Amy Luo