Part Number: SM72295
What could be the root cause of a defect input current measurement circuit (SIA~SOA)?
The output of BIN is incorrect. We have drivers with different error behavior: couple of amps error, random output and extreme high output.
The MPP-Tracker does not operate in the MPP of the PV module when the current measurement circuits is defect.
See schematic below, could you provide support.
Hi HOG, Welcome to e2e, and thanks for your interest in our products. I would suggest checking the following things to debug this issue: 1. Is the size of your sense resistor appropriate for your current levels? Is it too big or two small? This would cause the op amp to rail out. 2. Is the signal being fed into SIA and SOA noisy? You might need to add some capacitance to filter the signal if it's extremely noisy. You'll need to look at this differentially. 3. Is your IIN signal clean? This may require filtering if not.
Gate Driver Applications Engineering Manager
Dallas, TX USA
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
in addition to Don's suggestions add 10nF cap between SIA/SOA similar to page1 of the datasheet diagram.
The 10nF will help with keeping the voltage between these pins fixed and within spec to achieve an accurate reading.
You can likewise put a cap on IIN and in parallel with RL to achieve a steady gain.
In reply to Jeffrey Mueller:
Hi Jeff and Don, thanks for your reply.
A cap on Iin and Bin is already there, see schematic below. Is this okay?
The max specified PV current is 19A, so the shunt value 2.5mE. should be fine.
Our initial test shows that a 10nF cap between SIA and SOA reduce the noise on the input.
Do you have experience that the SIA/SOA input without the 10nF can break down overtime?
In reply to HOG:
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.