Part Number: BQ25505
I have the following circuit:
The BYP and REF capacitors are ceramic and the remaining capacitors are electrolyte. I have made another circuit for the BQ25570 with these elements with no problem. Also, the BAT2 voltage is 3.7V, not 9V.
The problem that I have here is that the boost charger does not seem to be working.
1- The VIN_DC is the same as the solar cell Voc.
2- The VREF_SAMP voltage is zero. I tried other capacitors but made no difference.
3- The Lboost voltage is the same as the VIN_DC.
4- The VSTOR voltage is around 150mv lower than VIN_DC.
5- The VIN_DC voltage does not change every 16 seconds meaning that the MPPT is not taking samples.
6- Voltage on the C1 capacitor stays at VIN_DC and does not increase. I initially had the OK_HYST and OK_PROG pins connected to mid-point of external resistors but that did not make a difference.
I was wondering if I could get some help on what might be wrong with this circuit.
Product Marketing Engineer
Texas Instruments Inc
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 reply to Upal Patel:
I connected the VOC_SAMP pin to the mid-point of two 10MOhm resistors (between VIN_DC and ground). But the VREF_SAMP voltage is still at zero. It seems that the MPPT modulate somehow does not work at all. All the voltage measurements are the same as what I reported in the question.
In reply to Vahid Montazeri63:
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.