SM3320-BATT-EV: The latest version of the SM3320-BATT_EV_Schematic is required

Hi CY,

Thanks for reaching out on e2e.

Can you share a snippet of the schematic you have?

Are you downloading the CAD/sch files from the link below?

Thanks,

Thank you, Jeff

SM3320-BATT_EV_Schematic.PDFSM3320-BATT_EV_Assembly.PDF

Yes, I downloaded the CAD files from the link you gave, and I attached SM3320-BATT_EV_Schematic and SM3320-BATT_EV_Assembly file above.

And here is the photograph of the board I have

You can see U10 near the red mark, which is not exsists in the CAD files. Also the components around U10, (such as Q5,Q6, R601, R602.etc) are not shown. 

Hence I need a latest schematic of this board. Thank you.

Regard

CY 

Hi CY,

Thanks for pointing out this assembly and schematic discrepancy to the board recieved.

Let me further investigate this issue and update you ASAP.

Thanks,

Hi Jeff,

Thank you for your help.

Please send the latest CAD files to me when you get them.

Thanks,

CY

HI Jeff,

Thank you but I don't think the Original U10 is same as the U10 on my board.

Here is the circut I made,  cheked by multi-meter. However, maybe missed some paths I don' t know.

So you can see it's very different from the original one.

But I still don't konw the fuction and model of U10, the U10 on my board maybe malfunction and that's why I want to know more about it. 

Thanks,

CY

Hi CY,

Thanks for the update,

Let me further investigate exactly what u10 is doing. Since there is no documentation that maybe difficult.

Can you explain how you think u10 is malfunctioning?

Thanks,

Hi CY,

u10 is for current sense to the battery. current sense from the PV input is taken care of SM72295 with SOA/SIA. The output of u10 goes to the MPPT controller (SM72442) panel mode which tells the controller to make sure MPPT is at max.

However on the schematic on the web I see that the current sense is done on both sides directly from sm72295.

To confirm what is doing the current sense, is sm72295 SIA/SOA pin connected to PV current sense resistor and is SIB/SOB connected to the output current sense resistor?

can you tell me the voltages on the pin of u10?

its possible that u10 is LMP7701 and somehow got damaged which is why the circuit is not making sense with the multimeter. its also possible that the true latest schematic is the one currently online and the silkscreen is off.

Thanks,

Hi Jeff,

In my case, I wanted to increase output voltage by change the value of R53.

However, there is a litter hole near the R53, when I soldering the new R53, the hole also be soldered, which was my fault.

And it means, R601 was shorted.

After this, the board never work again.  U10 maybe broke-down because of shorted R601.

A low signal is always appearing at the RST pin at SM72442, that's the reason why SM72442 is not working.

Then I took out U10 and Q6, the RST pin turned to high, SM72442 works,  but the output voltage is out of control.

"Is Sm72295 SIA/SOA pin connected to PV current sense resistor and is SIB/SOB connected to the output current sense resistor?" 

Yes, that's true.

"can you tell me the voltages on the pin of u10?"

Sorry, it need to test, but I am on vacation, may tell you after Feb.3rd.

I drew the circuit after U10  took out,  so the PCB connection maybe just like what I showed.

Thanks,

CY

Hi CY,

Thanks for the update.

Is R601 and R53 on the other side of the board?

I see. Are you able to use solder wick to suck up the solder in the through hole via?

Can you sample another u10 to see if that fixes it.

Does Q5 and 6 work?

It seems like u10 is just shorted since the board still works but with no control.

Thanks,

Hi Jeff,

That's right, R601 and R53 is on the other side of the board.

I was re-soldered R53 so R601 is not shorted now. However u10  maybe malfunction like I said.

I don't know what the model name of U10 is, if I know, I can buy some and do the test.

I think Q6 works because RST turn to 0. But Q5, I'm not sure.

Thanks,

CY

Hi CY,

Thanks for the update.

Is there any way you can tell me or take a picture of the marking on th he top of u10?

I may be able to see if it's a part we can look up.

Thanks,

Hi Jeff,

Sorry but I remember that there is no mark on the top of U10.

I'll check this again after I go back to my lab.

Thanks,

CY