Part Number: INA240-Q1
When Vs=0V,IB(Input Bias Current) is indicated on Fig.15 of DataSheet
In order to suppress this current, we want to suppress the current by adding an FET between GNGPIN and GRANDPLANE.
Is it possible to suppress the IB in this way?
Also is there any influence on the electric characteristics when FET is put in?
Best Regards Koji Hayashi
Mitch M, TI Sensing Products Applications Support
If this answered your question, please click below.
Getting Started with Current Sensing Video Training Series
TI makes no warranties and assumes no liability for applications assistance or customer product design. You are fully responsible for all design decisions and engineering with regard to your products, including decisions relating to application of TI products. By providing technical information, TI does not intend to offer or provide engineering services or advice concerning your designs.
In reply to Mitch M:
Thak you for four support.
When adding FET, does REFPIN connect to GNDPLANE?
Or is it connected to GNDPIN?
Written on P.12 of datasheet.
NOTE Do not connect the REF1 pin or the REF2 pin to any voltage source lower than GND or higher than VS.
Best RegardsKoji Hayashi
In reply to Koji Hayashi:
Either would be fine to do, but there are some trade-offs. For example, if you connect the REFPIN to GNDPLANE then you will still have a path to GND when your FET is open, although this would be very high resistance and would probably only leak on the order of micro amps. However, with this setup you would have a more accurate measurement than connecting the REFPIN to GNDPIN because when connecting to GNDPIN whatever voltage offset your FET introduces will show in your measurement. On the other hand, connecting to GNDPIN allows you to completely remove GND from your device when the FET is open, avoiding the small current leak. So it really depends on what is more important to your design.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.