Post by thread:[PIC]Internal Voltage Boost Assist for USB Bus Vol

my circuit uses PIC24FJ256GB110. i wanted to interface a USB flash memory stick. My PIC working voltage is 3V. PIC working as a usb host, so it should give 5V to the USB device. I want to use "Internal Voltage Boost Assist for USB Bus Voltage Generation" But i didnt get the required information or schematics. what i understood is VCPCON is pwm output, i connected this to a boost circuit. then the output is connected to the VBUS. but where to connect the VBUSST,VCMPST2 and VCMPST1 pins. Thanks in advance YOurs SaRIn....

-------------------------------------------------- From: "Sarin Sukumar A" <spam_OUTsarinsukumarTakeThisOuTgmail.com> Sent: Tuesday, July 13, 2010 12:54 PM To: "Microcontroller discussion list - Public." <.....piclistKILLspam@spam@mit.edu> Subject: [PIC]Internal Voltage Boost Assist for USB Bus Voltage Generation {Quote hidden}> my circuit uses PIC24FJ256GB110. i wanted to interface a USB flash memory > stick. > My PIC working voltage is 3V. > PIC working as a usb host, so it should give 5V to the USB device. > I want to use "Internal Voltage Boost Assist for USB Bus Voltage > Generation" > But i didnt get the required information or schematics. > > what i understood is > VCPCON is pwm output, i connected this to a boost circuit. then the output > is connected to the VBUS. > but where to connect the VBUSST,VCMPST2 and VCMPST1 pins. > > Thanks in advance Looking at the Family Reference Manual (DS39897C ~page 210), it looks as if all the info you need is in there. It has examples of Host/OTG circuits with an external charge pump to generate the 5V needed.

> > > > Looking at the Family Reference Manual (DS39897C ~page 210), it looks as if > all the info you need is in there. It has examples of Host/OTG circuits > with > an external charge pump to generate the 5V needed. > > I have read that portion. there it says you can generate by the help of internal boost assistance. But they are not providing any schematics or any information about hardware connections. I have referred the family reference manual also. But didnt find any info.. If any one know about this please replay. > > -

On Tue, 13 Jul 2010 22:08:02 +0530, "Sarin Sukumar A" said: > > I have read that portion. there it says you can generate by the help of > internal boost assistance. But they are not providing any schematics or > any > information about hardware connections. I have referred the family > reference > manual also. But didnt find any info.. > If any one know about this please replay. For schematics, download the documents for the demo board. Cheerful regards, Bob -- http://www.fastmail.fm - One of many happy users: http://www.fastmail.fm/docs/quotes.html

Final warning. Topic is PIC, change the tag if you want to discuss sentence structure. Bob On Tue, 13 Jul 2010 19:51:07 +0300, "Marechiare" said: > > Looking at the Family Reference Manual (DS39897C ~page 210), it > > looks as if all the info you need is in there. > > http://en.wikipedia.org/wiki/Dangling_modifier -- http://www.fastmail.fm - Email service worth paying for. Try it for free

hat: irrelevant > http://en.wikipedia.org/wiki/Dangling_modifier 1. And? 2. http://en.wikipedia.org/wiki/Pedant 3. If wishing to make points re pedantry, sophistry, euphony, sollipsism (although, I don't know about you ... :-) ), symphony, et al *** PLEASE *** (as frequently requested) change tag to [OT]: Changing subject line to eg "Random drivellings" is optional. ie leaving the subject line as is in OT at least shows what the intended target is, when / if one fails to include enough subject material to avoid a literary act e'n more heinous than the one alluded to. Points re bigotry, ethnicity, sexuality, et al should be made on some other list :-) Russell

YOurs SaRIn.... On Tue, Jul 13, 2010 at 10:31 PM, Bob Blick <bobblickKILLspamftml.net> wrote: > Final warning. Topic is PIC, change the tag if you want to discuss > sentence structure. > > Bob > > > I dont understand... i am asking about PIC24FJ256GB110 and its "Internal Voltage Boost Assist for USB HOST Bus Voltage Generation" I have checked the schematics of demo boards also.. None uses this feature. But in the data sheet they have specified about this

On Tue, 13 Jul 2010 22:57:39 +0530, "Sarin Sukumar A" said: > YOurs SaRIn.... > > I dont understand... > i am asking about PIC24FJ256GB110 and its "Internal Voltage Boost Assist > for USB HOST Bus Voltage Generation" I have checked the schematics of > demo > boards also.. None uses this feature. But in the data sheet they have > specified about this On page 211 of datasheet 39879c.pdf the impression I get is that this is a feature that Microchip has not fully fleshed-out. But I have no experience with that chip, so my suggestion is to use external powerwhile debugging, but set up the chip to use the PWM output, then look at it with an oscilloscope to determine what frequency is being used. Then choose a transistor, inductor, diode and capacitor by using the applications information from a Linear Technology or National Semiconductor boost regulator chip. That should get you to a close-enough starting place. Cheerful regards, Bob -- http://www.fastmail.fm - Accessible with your email software or over the web

Sarin >> I dont understand... Bob's comment was not directed to you. It was meant for somebody else who commented on somebody else's English. Your post is OK. > For schematics, download the documents for the demo board. If you can provide web addresses of all schematics and other documents concerned I can take a look and see if I can help Russell

-------------------------------------------------- From: "Sarin Sukumar A" <.....sarinsukumarKILLspam.....gmail.com> Sent: Tuesday, July 13, 2010 5:38 PM To: "Microcontroller discussion list - Public." <EraseMEpiclistspam_OUTTakeThisOuTmit.edu> Subject: Re: [PIC]Internal Voltage Boost Assist for USB Bus Voltage Generation {Quote hidden}>> >> >> >> Looking at the Family Reference Manual (DS39897C ~page 210), it looks as >> if >> all the info you need is in there. It has examples of Host/OTG circuits >> with >> an external charge pump to generate the 5V needed. >> >> I have read that portion. there it says you can generate by the help of > internal boost assistance. But they are not providing any schematics or > any > information about hardware connections. I have referred the family > reference > manual also. But didnt find any info.. > If any one know about this please replay. Ok sorry, I wasn't sure if you had read it from your first message, so I thought that may have been what you were looking for at first glance. Looking more closely, it doesn't seem to be dealt with very thoroughly in the manual. As Bob says, getting what info you can from the demo board schematics, and/or designing a small boost circuit based around the PWM frequency seem like a good way to go.

On Wed, 14 Jul 2010, RussellMc wrote: > > My vote is for "just" and "only" > > If people wish to just be able to vote, only be able to vote or just > only be able to vote, would they please use [OT] to do so, or not. > > NB: There was is nor shall be no voting on any matter which I am aware > of. Joe is / was just and only waxing lyrical. > "just" is a four letter word and I really hate it! Regards Sergio Masci

--000e0cd6e4b2c47cd6048b5744ef Content-Type: text/plain; charset=ISO-8859-1 YOurs SaRIn.... On Tue, Jul 13, 2010 at 3:48 PM, Oli Glaser <oli.glaserspam_OUTtalktalk.net> wrote: {Quote hidden}> > > -------------------------------------------------- > From: "Sarin Sukumar A" <@spam@sarinsukumarKILLspamgmail.com> > Sent: Tuesday, July 13, 2010 5:38 PM > To: "Microcontroller discussion list - Public." <KILLspampiclistKILLspammit.edu> > Subject: Re: [PIC]Internal Voltage Boost Assist for USB Bus Voltage > Generation > > >> > >> > >> > >> Looking at the Family Reference Manual (DS39897C ~page 210), it looks as > >> if > >> all the info you need is in there. It has examples of Host/OTG circuits > >> with > >> an external charge pump to generate the 5V needed. > >> > >> I have read that portion. there it says you can generate by the help of > > internal boost assistance. But they are not providing any schematics or > > any > > information about hardware connections. I have referred the family > > reference > > manual also. But didnt find any info.. > > If any one know about this please replay. > > Ok sorry, I wasn't sure if you had read it from your first message, so I > thought that may have been what you were looking for at first glance. > Looking more closely, it doesn't seem to be dealt with very thoroughly in > the manual. As Bob says, getting what info you can from the demo board > schematics, and/or designing a small boost circuit based around the PWM > frequency seem like a good way to go. > > I set it like this..shown in the figure. i am going to try this any way.... > > -

sergio masci wrote: > "just" is a four letter word and I really hate it! So just use "only" instead (although I think you're not being just). ******************************************************************** Embed Inc, Littleton Massachusetts, http://www.embedinc.com/products (978) 742-9014. Gold level PIC consultants since 2000.