Hi all I have to start a project with a MSP430 chip soon and I'm new to this microcontroller. Since I'll have to interface it with 5V devices (5V oututs AND inputs), I'm wondering what's the best wayto do this? Use a bus switch or can it be done in a simpler way? Thanks. CalinD
How to interface MSP430 chips with 5V devices?
Started by ●November 17, 2004
Reply by ●November 17, 20042004-11-17
Well I've found that, in the majority of cases a simple current
limiting
resistor is adequate, but there are plenty of level translators about,
or, for example chips that have a 3V supply and are 5V tolerant.
Al
calin_dorohoi wrote:
>
>
> Hi all
>
> I have to start a project with a MSP430 chip soon and I'm new to this
> microcontroller. Since I'll have to interface it with 5V devices (5V
> oututs AND inputs), I'm wondering what's the best wayto do this?
Use a
> bus switch or can it be done in a simpler way? Thanks.
>
> CalinD
>
>
>
>
>
>
>
>
>
>
> .
>
>
> Yahoo! Groups Links
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Reply by ●November 17, 20042004-11-17
----- Original Message -----
From: "onestone" <onestone@ones...>
To: <msp430@msp4...>
Sent: Wednesday, November 17, 2004 6:02 PM
Subject: Re: [msp430] How to interface MSP430 chips with 5V devices?
>
> Well I've found that, in the majority of cases a simple current
limiting
> resistor is adequate, but there are plenty of level translators about,
> or, for example chips that have a 3V supply and are 5V tolerant.
FWIW, Xilinx recommends a series resistor for their Virtex FPGAs. Their I/Os
are difficult to damage, according to one of their FAEs, on comp.arch.fpga.
Leon
Reply by ●November 17, 20042004-11-17
There is an app note of TI, Calin, "Interfacing the 3-V MSP430 to 5-V
Circuits" (slaa148.pdf). Search it on the TI site. And if you look at
past messages, you'll find this subject has already been discussed here
sometimes.
Regards,
Adriano.
calin_dorohoi wrote:
>
>
> Hi all
>
> I have to start a project with a MSP430 chip soon and I'm new to this
> microcontroller. Since I'll have to interface it with 5V devices (5V
> oututs AND inputs), I'm wondering what's the best wayto do this?
Use a
> bus switch or can it be done in a simpler way? Thanks.
>
> CalinD
>
>
>
>
>
>
>
>
>
>
> .
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
Reply by ●November 17, 20042004-11-17
I've found the MSP430 I/O remarkably robust, far better than you might
suspect from the spec. The recent discussion on 5V damage highlighted
this, that the MSP430 actually doesn't seem to be affected by 5V on I/O
or supply. I would not risk this of course, but, provided you check the
logic level requirements of the external devices, I have had no problems
in this area. In fact I directly drive the logic control pins of some #)
mux devices.
Al
Leon Heller wrote:
> ----- Original Message -----
> From: "onestone" <onestone@ones...>
> To: <msp430@msp4...>
> Sent: Wednesday, November 17, 2004 6:02 PM
> Subject: Re: [msp430] How to interface MSP430 chips with 5V devices?
>
>
>
>>Well I've found that, in the majority of cases a simple current
limiting
>>resistor is adequate, but there are plenty of level translators about,
>>or, for example chips that have a 3V supply and are 5V tolerant.
>
>
> FWIW, Xilinx recommends a series resistor for their Virtex FPGAs. Their
I/Os
> are difficult to damage, according to one of their FAEs, on comp.arch.fpga.
>
> Leon
>
>
>
>
> .
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
>
>
Reply by ●November 18, 20042004-11-18
contact me on my yahoo im or 0722938847 if you need to discuss a particular schematic calin_dorohoi <calin_dorohoi@cali...> wrote: Hi all I have to start a project with a MSP430 chip soon and I'm new to this microcontroller. Since I'll have to interface it with 5V devices (5V oututs AND inputs), I'm wondering what's the best wayto do this? Use a bus switch or can it be done in a simpler way? Thanks. CalinD . Yahoo! Groups Sponsor Get unlimited calls to U.S./Canada --------------------------------- . --------------------------------- Do you Yahoo!? Discover all thats new in My Yahoo!
Reply by ●November 18, 20042004-11-18
Maybe this helps: http://www.pjrc.com/tech/mp3/sta013.html Or maybe this (requires two transistors per connection though): http://www.edn.com/archives/1996/110796/23DI_02.htm If you need to do level shifting for a large number of signals (for example a bus) you should consider using something like a 74LCX245 buffer (I think 74LCV245 would also work in this case, but I'm not very sure). Bogdan On Wed, 17 Nov 2004 23:22:29 -0800 (PST), avram ionut <avramionut_m@avra...> wrote: > > contact me on my yahoo im or 0722938847 if you need to discuss a particular schematic > > calin_dorohoi <calin_dorohoi@cali...> wrote: > > Hi all > > I have to start a project with a MSP430 chip soon and I'm new to this > microcontroller. Since I'll have to interface it with 5V devices (5V > oututs AND inputs), I'm wondering what's the best wayto do this? Use a > bus switch or can it be done in a simpler way? Thanks. > > CalinD > > . > > Yahoo! Groups Sponsor > Get unlimited calls to > > U.S./Canada > > --------------------------------- > . > > --------------------------------- > Do you Yahoo!? > Discover all that's new in My Yahoo! > > > > > . > > > Yahoo! Groups Links > > > > > -- Bogdan
Reply by ●November 18, 20042004-11-18
Sorry, but I almost forgot about this: http://www.interfacebus.com/Design_Translation.html On Thu, 18 Nov 2004 10:38:19 +0200, Bogdan Marinescu <bogdan.marinescu@bogd...> wrote: > Maybe this helps: > > http://www.pjrc.com/tech/mp3/sta013.html > > Or maybe this (requires two transistors per connection though): > > http://www.edn.com/archives/1996/110796/23DI_02.htm > > If you need to do level shifting for a large number of signals (for > example a bus) you should consider using something like a 74LCX245 > buffer (I think 74LCV245 would also work in this case, but I'm not > very sure). > > Bogdan > > > > On Wed, 17 Nov 2004 23:22:29 -0800 (PST), avram ionut > <avramionut_m@avra...> wrote: > > > > contact me on my yahoo im or 0722938847 if you need to discuss a particular schematic > > > > calin_dorohoi <calin_dorohoi@cali...> wrote: > > > > Hi all > > > > I have to start a project with a MSP430 chip soon and I'm new to this > > microcontroller. Since I'll have to interface it with 5V devices (5V > > oututs AND inputs), I'm wondering what's the best wayto do this? Use a > > bus switch or can it be done in a simpler way? Thanks. > > > > CalinD > > > > . > > > > Yahoo! Groups Sponsor > > Get unlimited calls to > > > > U.S./Canada > > > > --------------------------------- > > . > > > > --------------------------------- > > Do you Yahoo!? > > Discover all that's new in My Yahoo! > > > > > > > > > > . > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > -- > Bogdan >
Reply by ●November 18, 20042004-11-18
Unfortunately I have to interface a lot of pins. Thanks for the links. --- In msp430@msp4..., Bogdan Marinescu <bogdan.marinescu@g...> wrote: > Sorry, but I almost forgot about this: > > http://www.interfacebus.com/Design_Translation.html > > > On Thu, 18 Nov 2004 10:38:19 +0200, Bogdan Marinescu > <bogdan.marinescu@g...> wrote: > > Maybe this helps: > > > > http://www.pjrc.com/tech/mp3/sta013.html > > > > Or maybe this (requires two transistors per connection though): > > > > http://www.edn.com/archives/1996/110796/23DI_02.htm > > > > If you need to do level shifting for a large number of signals (for > > example a bus) you should consider using something like a 74LCX245 > > buffer (I think 74LCV245 would also work in this case, but I'm not > > very sure). > > > > Bogdan > > > > > > > > On Wed, 17 Nov 2004 23:22:29 -0800 (PST), avram ionut > > <avramionut_m@y...> wrote: > > > > > > contact me on my yahoo im or 0722938847 if you need to discuss a particular schematic > > > > > > calin_dorohoi <calin_dorohoi@y...> wrote: > > > > > > Hi all > > > > > > I have to start a project with a MSP430 chip soon and I'm new to this > > > microcontroller. Since I'll have to interface it with 5V devices (5V > > > oututs AND inputs), I'm wondering what's the best wayto do this? Use a > > > bus switch or can it be done in a simpler way? Thanks. > > > > > > CalinD > > > > > > . > > > > > > Yahoo! Groups Sponsor > > > Get unlimited calls to > > > > > > U.S./Canada > > > > > > --------------------------------- > > > Yahoo! Groups Links > > > > > > To visit your group on the web, go to: > > > http://groups.yahoo.com/group/msp430/ > > > > > > . > > > > > > Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. > > > > > > --------------------------------- > > > Do you Yahoo!? > > > Discover all that's new in My Yahoo! > > > > > > > > > > > > > > > . > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > > > > > > > -- > > Bogdan > >
Reply by ●November 18, 20042004-11-18
1. Most peripherals are available in 3V versions now. The only thing I
can't easily find are 3V gyros, and Honeywells HMC1053. other sensors
are no issue. Other logic is all available in one form.
2. Provided there is no real current requirement, ie signals are just
for control and communication, then current limiting resistors are more
than enough.
Al
calin_dorohoi wrote:
>
> Unfortunately I have to interface a lot of pins. Thanks for the links.
>
> --- In msp430@msp4..., Bogdan Marinescu
> <bogdan.marinescu@g...> wrote:
>
>>Sorry, but I almost forgot about this:
>>
>>http://www.interfacebus.com/Design_Translation.html
>>
>>
>>On Thu, 18 Nov 2004 10:38:19 +0200, Bogdan Marinescu
>><bogdan.marinescu@g...> wrote:
>>
>>>Maybe this helps:
>>>
>>>http://www.pjrc.com/tech/mp3/sta013.html
>>>
>>>Or maybe this (requires two transistors per connection though):
>>>
>>>http://www.edn.com/archives/1996/110796/23DI_02.htm
>>>
>>>If you need to do level shifting for a large number of signals (for
>>>example a bus) you should consider using something like a 74LCX245
>>>buffer (I think 74LCV245 would also work in this case, but I'm
not
>>>very sure).
>>>
>>>Bogdan
>>>
>>>
>>>
>>>On Wed, 17 Nov 2004 23:22:29 -0800 (PST), avram ionut
>>><avramionut_m@y...> wrote:
>>>
>>>>contact me on my yahoo im or 0722938847 if you need to discuss a
>
> particular schematic
>
>>>>calin_dorohoi <calin_dorohoi@y...> wrote:
>>>>
>>>>Hi all
>>>>
>>>>I have to start a project with a MSP430 chip soon and I'm
new to
>
> this
>
>>>>microcontroller. Since I'll have to interface it with 5V
devices (5V
>>>>oututs AND inputs), I'm wondering what's the best
wayto do this?
>
> Use a
>
>>>>bus switch or can it be done in a simpler way? Thanks.
>>>>
>>>>CalinD
>>>>
>>>>.
>>>>
>>>>Yahoo! Groups Sponsor
>>>>Get unlimited calls to
>>>>
>>>>U.S./Canada
>>>>
>>>>---------------------------------
>>>>Yahoo! Groups Links
>>>>
>>>> To visit your group on the web, go to:
>>>>http://groups.yahoo.com/group/msp430/
>>>>
>>>> .
>>>>
>>>> Your use of Yahoo! Groups is subject to the Yahoo! Terms of
>
> Service.
>
>>>>---------------------------------
>>>>Do you Yahoo!?
>>>> Discover all that's new in My Yahoo!
>>>>
>>>>
>>>>
>>>>
>>>>.
>>>>
>>>>
>>>>Yahoo! Groups Links
>>>>
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>>--
>>>Bogdan
>>>
>
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>
>
>
> .
>
>
> Yahoo! Groups Links
>
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>
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>
