Hysteresis on dsPIC ports?
in [Design]
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From: Joerg on 27 Jan 2010 16:06 Jim Thompson wrote: > On Wed, 27 Jan 2010 11:22:02 -0800, Joerg <invalid(a)invalid.invalid> > wrote: > >> Joel Koltner wrote: >>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>> news:7sbhbmFt77U1(a)mid.individual.net... >>>> This one just has to be small. I can make uC products work very >>>> reliably without fancy circuitry around them, have done it many times. >>>> _If_ the uC is properly characterized, which this one is not. I would >>>> not have picked it but was already in there. >>> What's the cost of fixing the many flaky internal power-on reset >>> circuits that you've seen many of? :-) >>> >> In terms of components? Well under 50c, even in IC form. These little >> dudes are quite nice at around 15c a pop in qties: >> >> http://www.onsemi.com/pub_link/Collateral/NCP302-D.PDF >> >> The cost to the business before the fix? Huge. Because it often results >> in a service call, or a truck roll in utility speak. > > Done right, it's quite a bit of circuitry. One I did recently, that > tested 3 supplies plus had a delay after voltages were AOK, was close > to 15% of the active chip area :-( > Get the library for the NCP30x from ON Semi? Don't you have good connections to them? -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Joerg on 27 Jan 2010 16:10 Jan Panteltje wrote: > On a sunny day (Wed, 27 Jan 2010 11:22:02 -0800) it happened Joerg > <invalid(a)invalid.invalid> wrote in <7sbi2vF1itU1(a)mid.individual.net>: > >> Joel Koltner wrote: >>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>> news:7sbhbmFt77U1(a)mid.individual.net... >>>> This one just has to be small. I can make uC products work very >>>> reliably without fancy circuitry around them, have done it many times. >>>> _If_ the uC is properly characterized, which this one is not. I would >>>> not have picked it but was already in there. >>> What's the cost of fixing the many flaky internal power-on reset >>> circuits that you've seen many of? :-) >>> >> In terms of components? Well under 50c, even in IC form. These little >> dudes are quite nice at around 15c a pop in qties: >> >> http://www.onsemi.com/pub_link/Collateral/NCP302-D.PDF > > PICs have that all build in :) Yes, finally. Here's hoping that it's good enough :-) -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Jim Thompson on 27 Jan 2010 16:42 On Wed, 27 Jan 2010 13:06:44 -0800, Joerg <invalid(a)invalid.invalid> wrote: >Jim Thompson wrote: >> On Wed, 27 Jan 2010 11:22:02 -0800, Joerg <invalid(a)invalid.invalid> >> wrote: >> >>> Joel Koltner wrote: >>>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>>> news:7sbhbmFt77U1(a)mid.individual.net... >>>>> This one just has to be small. I can make uC products work very >>>>> reliably without fancy circuitry around them, have done it many times. >>>>> _If_ the uC is properly characterized, which this one is not. I would >>>>> not have picked it but was already in there. >>>> What's the cost of fixing the many flaky internal power-on reset >>>> circuits that you've seen many of? :-) >>>> >>> In terms of components? Well under 50c, even in IC form. These little >>> dudes are quite nice at around 15c a pop in qties: >>> >>> http://www.onsemi.com/pub_link/Collateral/NCP302-D.PDF >>> >>> The cost to the business before the fix? Huge. Because it often results >>> in a service call, or a truck roll in utility speak. >> >> Done right, it's quite a bit of circuitry. One I did recently, that >> tested 3 supplies plus had a delay after voltages were AOK, was close >> to 15% of the active chip area :-( >> > >Get the library for the NCP30x from ON Semi? Don't you have good >connections to them? ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
From: Jim Thompson on 27 Jan 2010 16:43 On Wed, 27 Jan 2010 13:06:44 -0800, Joerg <invalid(a)invalid.invalid> wrote: >Jim Thompson wrote: >> On Wed, 27 Jan 2010 11:22:02 -0800, Joerg <invalid(a)invalid.invalid> >> wrote: >> >>> Joel Koltner wrote: >>>> "Joerg" <invalid(a)invalid.invalid> wrote in message >>>> news:7sbhbmFt77U1(a)mid.individual.net... >>>>> This one just has to be small. I can make uC products work very >>>>> reliably without fancy circuitry around them, have done it many times. >>>>> _If_ the uC is properly characterized, which this one is not. I would >>>>> not have picked it but was already in there. >>>> What's the cost of fixing the many flaky internal power-on reset >>>> circuits that you've seen many of? :-) >>>> >>> In terms of components? Well under 50c, even in IC form. These little >>> dudes are quite nice at around 15c a pop in qties: >>> >>> http://www.onsemi.com/pub_link/Collateral/NCP302-D.PDF >>> >>> The cost to the business before the fix? Huge. Because it often results >>> in a service call, or a truck roll in utility speak. >> >> Done right, it's quite a bit of circuitry. One I did recently, that >> tested 3 supplies plus had a delay after voltages were AOK, was close >> to 15% of the active chip area :-( >> > >Get the library for the NCP30x from ON Semi? Don't you have good >connections to them? Nope. That's proprietary to National. They'd never share their IP. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
From: Jan Panteltje on 27 Jan 2010 17:31
On a sunny day (Wed, 27 Jan 2010 13:02:48 -0800) it happened "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote in <ZR18n.147895$oC1.77725(a)en-nntp-01.dc1.easynews.com>: >"WangoTango" <Asgard24(a)mindspring.com> wrote in message >news:MPG.25ca7071767c861498ae89(a)news.east.earthlink.net... >> Yep, turn on the PUT, the WDT, the BOR, and you have a pretty damn good >> chance of powering up in a known state. Turn on the OSC fail interrupt >> and you are really cooking with gas. > >Will PICs do "failover" to an internal RC clock if the xtal (or other external >clock input) doesn't fire up? I used some MSP430s a large handful of years >ago that did that, and thought it was pretty slick. Yes, some do, from the 18F14K22 dataheet: 2.12.2 FAIL-SAFE OPERATION When the external clock fails, the FSCM switches the device clock to an internal clock source and sets the bit flag OSCFIF of the PIR2 register. The OSCFIF flag will generate an interrupt if the OSCFIE bit of the PIE2 register is also set. The device firmware can then take steps to mitigate the problems that may arise from a failed clock. The system clock will continue to be sourced from the internal clock source until the device firmware successfully restarts the external oscillator and switches back to external operation. An automatic transition back to the failed clock source will not occur. |