MSP430FR5738: Need recommendation on which MSP430 to use

Gary Armstrong

Part Number: MSP430FR5738

I have inherited a design using a MSP430FR5738c58 (?? hard to read) that controls a high voltage power supply. The power supply is very noisy and appears to kill the MSP occasionally. We have contracted a specialist to do a new design on the HV PS but would like to use a MSP430 that could be more easily replaced than the current one. Would like 64kB of FRAM or FLASH and ~ 24 pins. Most of my experience has been with the FR58xx/59xx family of devices but we are more concerned with a low pin count and ability to replace the chip on a surface mount PCB.

over 6 years ago

0 Nathan Siegel over 6 years ago

TI__Genius 10980 points

Hi Gary,

Could you please explain what you mean by "more easily replaced"? What made the part that you are currently using hard to replace?

Also, to get an MSP430 with 64kB of nonvolatile memory, you are going to need to use a part that has at least 33 IOs (for a total of 38 pins). Why are you interested in a low pin count? If you need a lower pin count (than 38), you will need to use a part that has less that 64kB of nonvolatile memory.

Regards,
Nathan

0 Gary Armstrong over 6 years ago in reply to Nathan Siegel

Expert 1845 points

Could you please explain what you mean by "more easily replaced"? We want to remove the MSP and hand solder a new one in its place.
Why are you interested in a low pin count? We want to remove the MSP and hand solder a new one in its place.

The 64kB memory is not a priority, the current design is using 16kB. Would like to not have to modify the PCB design if we run out of memory in future designs. If 38 pins is the best option we will evaluate it.

0 Nathan Siegel over 6 years ago in reply to Gary Armstrong

TI__Genius 10980 points

Hi Gary,

I think I may still not be understanding the part about replacing the MSP. If you want to solder on a new MSP without modifying the PCB, then you would need to use a pin-compatible MSP with the same package type, so it wouldn't be any easier or harder to replace.

As for the memory considerations, you could get a 32kB MSP with 28 pins. This would be the MSP430I2021 (or other MSP430I20x1 parts).

Regards,

Nathan

0 Gary Armstrong over 6 years ago in reply to Nathan Siegel

Expert 1845 points

Okay I will take a look at the 2021. The FR5738 is about the size of a pencil head and the leads look like tiny wires. I need something physically bigger that I can work with. I have been out of the hardware end of uC dev for a while but there are larger packages available. MicroChip has a page comparing their package specifications for this uC but I can't find a similar page for the MSP430. www.microchip.com/.../packaging-specifications

0 Gary Armstrong over 6 years ago in reply to Gary Armstrong

Expert 1845 points

We are changing the PCB right now which gives us the opportunity to select a different MSP430.

0 Alexey Bagaev over 6 years ago

Genius 5435 points

Changing the MSP does not changing the issues with bad high-voltage design, that causes damaging low voltage part. Use additional high voltage isolation to avoid such conditions.

0 Gary Armstrong over 6 years ago in reply to Alexey Bagaev

Expert 1845 points

Per my first post "The power supply is very noisy and appears to kill the MSP occasionally. We have contracted a specialist to do a new design on the HV PS but would like to use a MSP430 that could be more easily replaced than the current one". I'm starting to think there is a language or possible culture issue here. What country are you in?

0 Alexey Bagaev over 6 years ago in reply to Gary Armstrong

Genius 5435 points

When it comes to high voltage it doesn't matter what culture is. But for some engineers 5V is a high voltage, for others - 500V. The first one can damage MSP easily just to apply it on any pin, the other one can go through isolation barrier even as a parasitic current. But when it comes to social aspects even this doesn't matter at all.

0 Alexey Bagaev over 6 years ago in reply to Gary Armstrong

Genius 5435 points

I'm not English native nor live in English speaking country. Anything else you need to know about me?

0 Gary Armstrong over 6 years ago in reply to Alexey Bagaev

Expert 1845 points

Sorry, no offense, but we just don't seem to be communicating. I'm not asking for help with HV issues. I'm asking for help on selecting a MSP430 uC?

0 Keith Barkley over 6 years ago in reply to Gary Armstrong

Guru 35620 points

I would create a daughter board that would allow for *really* easy replacement of the MCU.

0 Alexey Bagaev over 6 years ago in reply to Gary Armstrong

Genius 5435 points

In MSP range you wouldn't have better solution than you have now - FR5994 has 6 prioritized DMA channels, plenty of ADC channel, DPS like LEA for transient response analysis (www.ti.com/.../TIDA-00929 ) and, of course, TimerB, which is essential for most HV application. I don't know your HV topology, in some cases utilizing MSP430 is not good solution due to complexity and many other factors.

0 Gary Armstrong over 6 years ago in reply to Alexey Bagaev

Expert 1845 points

okay this is pointless, even the title of this thread is MSP430FR5738: Need recommendation on which MSP430 to use??? Have a good day.

0 Alexey Bagaev over 6 years ago in reply to Gary Armstrong

Genius 5435 points

Ohh.... "most of my experience has been with the FR58xx/59xx".... By the way, you can use qfn48 socket for hot replacement option. But this is pointless.... you need qfn24 package.

0 Nathan Siegel over 6 years ago in reply to Gary Armstrong

TI__Genius 10980 points

Hi Gary,

I apologize for the confusion in this thread. To get back to your point about packages, you can use this page to find more information: www.ti.com/.../find_packages.page

Using the "Find product by package" tab, you can even search for products with a given package type, or find out which package type a given product is available in. This should help you figure out which packages and products would be easiest for you to hand solder and replace.

Regards,
Nathan

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MSP430FR5738: Need recommendation on which MSP430 to use