Thank you Luis it is very clear and i do appreciate it. In regard to my latest question would it be fair to say that all the DVCC are connected together as well as all the AVCC . We just then have to connect the AVCC and DVCC in one place?

Thanks,

John.
________________________________
From: Luis Filipe Rossi
To: m...
Sent: Wednesday, January 9, 2013 9:45 AM
Subject: Re: [msp430] VBUS on MSP430F5529

Hello John,

The circuit works as follows. Considering a VBUS of 5V and a VBAT of 3.7V.
When USB is connected the volltage at MOSFET GATE will be 5V and the
voltage at Mosfet Source will be 5V - VF. In this scenario you got a
positive VGS and the mosfet is blocked. Also the mosfet body diode is
reverse polarized so it is not conducting. When USB is not connecting the
MOSFET GATE is pulled to ground. Also in a initial solution the Voltage at
MOSFET Source is something close to 0V. In such situation the mosfet would
be also blocked. However the body diode will start to conduct creating a
negative VGS value and turning ON the mosfet.

Let me know if i was enough clear.
Regarding DVCC and AVCC, yes you must connect then externally. If you
really need a clean AD measurement you should also filter your VCC with a
ferrite bead before connecting to AVCC.

Regards,
On Wed, Jan 9, 2013 at 4:10 AM, john Mcdonald wrote:

> **
> Hello all,
>
> Thank you for your reply. I like your circuit Luisf a lot. It works but
> I am not sure why. Does it have to due to the threshold?
> One further question in MSP430F5529 does DVCC and AVCC pins are internally
> connected or we have to connect them externally?
>
> High Regards,
>
> John.
>
> ________________________________
> From: Luis Filipe Rossi l...@gmail.com>
> To: m...
> Sent: Monday, January 7, 2013 7:35 AM
> Subject: Re: [msp430] VBUS on MSP430F5529
> There you go:
>
> http://i.imgur.com/r6bDg.png?1
>
> Of course the VOUT must be regulated to be used with MSP430
>
> Regards,
>
> On Mon, Jan 7, 2013 at 1:29 PM, Kyle Lewis k...@gmail.com> wrote:
>
> > **
>
> >
> >
> > Luis, thanks for the information. But I cannot see your image, would you
> > mind uploading it to a host, for example http://www.imgur.com
> >
> > Thanks,
> > Kyle
> >
> > On Mon, Jan 7, 2013 at 7:11 AM, Luis Filipe Rossi l...@gmail.com
> > >wrote:
> >
> >
> > > It is infact very simple. The mosfet gate is controlled by the external
> > > voltage.
> > >
> > > Take a look:
> > >
> > > [image: Inline image 2]
> > > Where VAUX is VBUS.
> > >
> > > So if VBUS is present and VBAT is always lower than VBUS - the Diode Vf
> > > (considering a standard LiPo or LiIon Battery with 4.2V charged
> voltage)
> > > when the USB is connected it will block MOSFET conduction and supply
> > VOUT.
> > > When VAUX is floating the gate will be pulled to ground and turn the
> > MOSFET
> > > On.
> > >
> > > You just need a low Ron Mosfet but that is simple to find.
> > >
> > > Regards,
> > >
> > > On Mon, Jan 7, 2013 at 9:37 AM, Adeilton Oliveira <
> > > a...@gmail.com> wrote:
> > >
> > > > **
> >
> > > >
> > > >
> > > > Isn't it necessary to control the mosfet gate? I guess it is not that
> > > > simple as to replace a diode by a mosfet.
> > > >
> > > > 2013/1/7 Luis Filipe Rossi l...@gmail.com>
> > > >
> > > >
> > > > > Use a P Channel MOSFET.
> > > > >
> > > > > On Mon, Jan 7, 2013 at 2:27 AM, John e...@yahoo.com> wrote:
> > > > >
> > > > > > **
> > > >
> > > > > >
> > > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > I was just wondering if I have a unit running on a battery how I
> > can
> > > > swap
> > > > > > the supply voltage with the VBUS when the MSP430F5529 is
> connected
> > to
> > > > PC
> > > > > > through the USB interface? I know to connect the battery and the
> > VBUS
> > > > > > together through diodes. There is a disadvantage this way which
> > drops
> > > > the
> > > > > > battery voltage by 0.4V. Any suggestion would be appreciated.
> > > > > >
> > > > > > Thanks,
> > > > > >
> > > > > > John.
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Lu Filipe Rossi
> > > > > Electrical Engineer
> > > > > Biomechatronics Lab. / Grupo de Sensores Integreis e Sistemas
> > > > > Escola Politnica
> > > > > Universidade de S Paulo
> > > > > Cel. +55 (11) 7662-9234
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > > >
> > > > >
> > > > >
> > > > > Start a New Thread

Thank you Jake,

John.

________________________________
From: Jake G
To: m...
Sent: Wednesday, January 9, 2013 9:44 AM
Subject: Re: [msp430] VBUS on MSP430F5529


 
Hi John,

I am not 100% sure if you need that but you can check the example
circuit boards put out by TI. One thing I always do if I am learning a
new processor family is to get, the Data sheet for your the specific
chip, the family user guide of your chip , and the schematic of the
experimenter board for your chip. If you want to make programming and
designing circuits easier for yourself spend the time to at least skim
those documents and always have them in hand, because they will help.

Jake G.

On 1/8/2013 10:10 PM, john Mcdonald wrote:
>
> Hello all,
>
> Thank you for your reply. I like your circuit Luisf a lot. It works
> but I am not sure why. Does it have to due to the threshold?
> One further question in MSP430F5529 does DVCC and AVCC pins are
> internally connected or we have to connect them externally?
>
> High Regards,
>
> John.
>
> ________________________________
> From: Luis Filipe Rossi l...@gmail.com
> >
> To: m...
> Sent: Monday, January 7, 2013 7:35 AM
> Subject: Re: [msp430] VBUS on MSP430F5529
>
> There you go:
>
> http://i.imgur.com/r6bDg.png?1
>
> Of course the VOUT must be regulated to be used with MSP430
>
> Regards,
>
> On Mon, Jan 7, 2013 at 1:29 PM, Kyle Lewis k...@gmail.com
> > wrote:
>
> > **
> >
> >
> > Luis, thanks for the information. But I cannot see your image, would you
> > mind uploading it to a host, for example http://www.imgur.com
> >
> > Thanks,
> > Kyle
> >
> > On Mon, Jan 7, 2013 at 7:11 AM, Luis Filipe Rossi
> l...@gmail.com
> > >wrote:
> >
> >
> > > It is infact very simple. The mosfet gate is controlled by the
> external
> > > voltage.
> > >
> > > Take a look:
> > >
> > > [image: Inline image 2]
> > > Where VAUX is VBUS.
> > >
> > > So if VBUS is present and VBAT is always lower than VBUS - the
> Diode Vf
> > > (considering a standard LiPo or LiIon Battery with 4.2V charged
> voltage)
> > > when the USB is connected it will block MOSFET conduction and supply
> > VOUT.
> > > When VAUX is floating the gate will be pulled to ground and turn the
> > MOSFET
> > > On.
> > >
> > > You just need a low Ron Mosfet but that is simple to find.
> > >
> > > Regards,
> > >
> > > On Mon, Jan 7, 2013 at 9:37 AM, Adeilton Oliveira <
> > > a...@gmail.com
> > wrote:
> > >
> > > > **
> >
> > > >
> > > >
> > > > Isn't it necessary to control the mosfet gate? I guess it is not
> that
> > > > simple as to replace a diode by a mosfet.
> > > >
> > > > 2013/1/7 Luis Filipe Rossi l...@gmail.com
> >
> > > >
> > > >
> > > > > Use a P Channel MOSFET.
> > > > >
> > > > > On Mon, Jan 7, 2013 at 2:27 AM, John e...@yahoo.com
> > wrote:
> > > > >
> > > > > > **
> > > >
> > > > > >
> > > > > >
> > > > > > Hi all,
> > > > > >
> > > > > > I was just wondering if I have a unit running on a battery how I
> > can
> > > > swap
> > > > > > the supply voltage with the VBUS when the MSP430F5529 is
> connected
> > to
> > > > PC
> > > > > > through the USB interface? I know to connect the battery and the
> > VBUS
> > > > > > together through diodes. There is a disadvantage this way which
> > drops
> > > > the
> > > > > > battery voltage by 0.4V. Any suggestion would be appreciated.
> > > > > >
> > > > > > Thanks,
> > > > > >
> > > > > > John.
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Luís Filipe Rossi
> > > > > Electrical Engineer
> > > > > Biomechatronics Lab. / Grupo de Sensores Integráveis e Sistemas
> > > > > Escola Politécnica
> > > > > Universidade de São Paulo
> > > > > Cel. +55 (11) 7662-9234
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > > > >
> > > > >
>
> > > > >
> > > > > Start a New Thread

Hello, John!

Usually DVcc and Avcc are connected together without any losses.... but, if
you're mixing an analog system with a digital system, Avcc and Dvcc
shouldn't be connected together...

An example: An analog system (op amps and filtering) to acquire ECG from a
person. The output of this analog system is connected to the ADC of the
MSP.
When separating grounds and power (analog from digital - if you're using an
external reference for the DAC this happens too!), your system robustness
improves greatly!

You can find this type of info in User Guides available in ti's page.

Regards and gl with your project!
On Thu, Jan 10, 2013 at 3:21 AM, john Mcdonald wrote:

> **
> Thank you Jake,
>
> John.
>
> ________________________________
> From: Jake G p...@gmail.com>
> To: m...
> Sent: Wednesday, January 9, 2013 9:44 AM
>
> Subject: Re: [msp430] VBUS on MSP430F5529
>
> Hi John,
>
> I am not 100% sure if you need that but you can check the example
> circuit boards put out by TI. One thing I always do if I am learning a
> new processor family is to get, the Data sheet for your the specific
> chip, the family user guide of your chip , and the schematic of the
> experimenter board for your chip. If you want to make programming and
> designing circuits easier for yourself spend the time to at least skim
> those documents and always have them in hand, because they will help.
>
> Jake G.
>
> On 1/8/2013 10:10 PM, john Mcdonald wrote:
> >
> >
> >
> > Hello all,
> >
> > Thank you for your reply. I like your circuit Luisf a lot. It works
> > but I am not sure why. Does it have to due to the threshold?
> > One further question in MSP430F5529 does DVCC and AVCC pins are
> > internally connected or we have to connect them externally?
> >
> > High Regards,
> >
> > John.
> >
> > ________________________________
> > From: Luis Filipe Rossi l...@gmail.com
> > >
> > To: m...
> > Sent: Monday, January 7, 2013 7:35 AM
> > Subject: Re: [msp430] VBUS on MSP430F5529
> >
> > There you go:
> >
> > http://i.imgur.com/r6bDg.png?1
> >
> > Of course the VOUT must be regulated to be used with MSP430
> >
> > Regards,
> >
> > On Mon, Jan 7, 2013 at 1:29 PM, Kyle Lewis k...@gmail.com
> > > wrote:
> >
> > > **
> > >
> > >
> > > Luis, thanks for the information. But I cannot see your image, would
> you
> > > mind uploading it to a host, for example http://www.imgur.com
> > >
> > > Thanks,
> > > Kyle
> > >
> > > On Mon, Jan 7, 2013 at 7:11 AM, Luis Filipe Rossi
> > l...@gmail.com
> > > >wrote:
> > >
> > >
> > > > It is infact very simple. The mosfet gate is controlled by the
> > external
> > > > voltage.
> > > >
> > > > Take a look:
> > > >
> > > > [image: Inline image 2]
> > > > Where VAUX is VBUS.
> > > >
> > > > So if VBUS is present and VBAT is always lower than VBUS - the
> > Diode Vf
> > > > (considering a standard LiPo or LiIon Battery with 4.2V charged
> > voltage)
> > > > when the USB is connected it will block MOSFET conduction and supply
> > > VOUT.
> > > > When VAUX is floating the gate will be pulled to ground and turn the
> > > MOSFET
> > > > On.
> > > >
> > > > You just need a low Ron Mosfet but that is simple to find.
> > > >
> > > > Regards,
> > > >
> > > > On Mon, Jan 7, 2013 at 9:37 AM, Adeilton Oliveira <
> > > > a...@gmail.com
> > > wrote:
> > > >
> > > > > **
> > >
> > > > >
> > > > >
> > > > > Isn't it necessary to control the mosfet gate? I guess it is not
> > that
> > > > > simple as to replace a diode by a mosfet.
> > > > >
> > > > > 2013/1/7 Luis Filipe Rossi l...@gmail.com
> > >
> > > > >
> > > > >
> > > > > > Use a P Channel MOSFET.
> > > > > >
> > > > > > On Mon, Jan 7, 2013 at 2:27 AM, John e...@yahoo.com
> > > wrote:
> > > > > >
> > > > > > > **
> > > > >
> > > > > > >
> > > > > > >
> > > > > > > Hi all,
> > > > > > >
> > > > > > > I was just wondering if I have a unit running on a battery how
> I
> > > can
> > > > > swap
> > > > > > > the supply voltage with the VBUS when the MSP430F5529 is
> > connected
> > > to
> > > > > PC
> > > > > > > through the USB interface? I know to connect the battery and
> the
> > > VBUS
> > > > > > > together through diodes. There is a disadvantage this way which
> > > drops
> > > > > the
> > > > > > > battery voltage by 0.4V. Any suggestion would be appreciated.
> > > > > > >
> > > > > > > Thanks,
> > > > > > >
> > > > > > > John.
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > --
> > > > > > Lu Filipe Rossi
> > > > > > Electrical Engineer
> > > > > > Biomechatronics Lab. / Grupo de Sensores Integreis e Sistemas
> > > > > > Escola Politnica
> > > > > > Universidade de S Paulo
> > > > > > Cel. +55 (11) 7662-9234
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > > >
> > > > > >
> >
> > > > > >
> > > > > > Start a New Thread