rickman <spamgoeshere4@yahoo.com> wrote in message news:<40509B43.DF463F05@yahoo.com>...> I have only found two other devices that > can implement an RTC from battery at automotive temps. One is a Dallas > part that includes a thermometer, but they don't spec the RTC at the > full temp range and the other is the microBuddy from Semtech. This one > is not "spec'd" over automotive temp range, but they publish calibration > curves up to 125C and they say it will operate. > > My incentive to using a different solution is to lower the cost. So if > the MARC4 EEPROM chips and/or tools come in at a high dollar, I will > have to forget them. >Lattice Zeropower CPLDs operate over a Tj of -55C to +150C. At 32 kHz, probably 15uA or so at 1.7 to 1.9V. Xilinx has something similar but with a little higher current. If you don't have much to do, you could try doing it all in hardware.
Thank you Jeff Fox
Started by ●March 9, 2004
Reply by ●March 11, 20042004-03-11
Reply by ●March 12, 20042004-03-12
On 12 Mar 04 at group /comp/lang/forth in article <40515133.9ABDB5A9@yahoo.com> <spamgoeshere4@yahoo.com> (rickman) wrote:>I am familiar with both the Cygnal (si labs) parts as well as >amrForth. But it would be a tough sell to get a vendor to qualify >parts outside their normal range. I can't put a part on my board that >the vendor can't tell me will work. There are coils, for example, >that only spec down to -25C. Normally low temps are not a problem, >but they say they can't meet the temp shock tests below -25C. So I am >not going to argue with them.However are there Li batteries specified for -40C to 125C?>I would like to use a Cygnal part as a Dallas 1-wire replacement. But >the cost is too high, even for the 11 pin parts. I would need >something under $1.50 (industrial temp range, not automotive). I know >a lot of people like the Cygnal parts, but I find them over priced for >most apps.Sadly yes :-( Bye from Germany Wolfgang -- FORTHing @ work | *Cheap* ...pick any Dipl.-Ing. Wolfgang Allinger | *Fast* *Good* ... *two* of them Germany ------------------------------------ ## KreuzPunkt XP2 R ## | reply address set
Reply by ●March 12, 20042004-03-12
On 12 Mar 04 at group /de/comp/lang/forth in article <4052092E.5B61F690@yahoo.com> <spamgoeshere4@yahoo.com> (rickman) wrote:>Wolfgang Allinger wrote:>> However are there Li batteries specified for -40C to 125C?>Oh yes. Panasonic has a line of coin cells that are rated over this >full range. There is also a movement to provide batteries to use in >tires for pressure sensing. These new devices will be rated for -40 >to 125C as well.THX, I didn't know that. I'll keep it in my mind.>There are other devices, when I get to that point, I will put together >a list of all the small MLF devices and pick one. That 11 pin package >is really nice and small though.Yes, you could put the 3x3x1mm package in a M6 screw. If you could find someone who fixes a DB9 to it, you may communicate via RS232 to the F300 :-) Bye from Germany Wolfgang -- FORTHing @ work | *Cheap* ...pick any Dipl.-Ing. Wolfgang Allinger | *Fast* *Good* ... *two* of them Germany ------------------------------------ ## KreuzPunkt XP2 R ## | reply address set
Reply by ●March 12, 20042004-03-12
Brad Eckert wrote:> > rickman <spamgoeshere4@yahoo.com> wrote in message news:<40509B43.DF463F05@yahoo.com>... > > I have only found two other devices that > > can implement an RTC from battery at automotive temps. One is a Dallas > > part that includes a thermometer, but they don't spec the RTC at the > > full temp range and the other is the microBuddy from Semtech. This one > > is not "spec'd" over automotive temp range, but they publish calibration > > curves up to 125C and they say it will operate. > > > > My incentive to using a different solution is to lower the cost. So if > > the MARC4 EEPROM chips and/or tools come in at a high dollar, I will > > have to forget them. > > > Lattice Zeropower CPLDs operate over a Tj of -55C to +150C. At 32 kHz, > probably 15uA or so at 1.7 to 1.9V. Xilinx has something similar but > with a little higher current. > > If you don't have much to do, you could try doing it all in hardware.I looked at the hardware approach, but you can't do an RTC in a CPLD, not enough bits. Hardware is actually the wrong direction since it normally is better when you need speed. Time is not an issue, an MCU could run on a 32 kHz clock and never switch to a high speed mode. To get a Li cell to last 5 years (BR1624A) you need to be under 2.7 uA. So even 15 uA is too large. Also, the Lattice part needs 1.8 volts to run at low power. I have not found an LDO with a quiescent current low enough, many "low current" devices are over 50 uA. The CPLDs are all durn big too. I think the Lattice parts can be found in a 48 TQFP which is 9 mm sq, but the Xilinx part is a 44 LQFP which is over 14 mm sq, IIRC. I would like something in a QFN around 7 mm or less. I have not found any automotive temp QFNs other than the PICs. They don't get down to this low current, so I would have to use a separate RTC which is what I am trying to optimize out :) -- Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX
Reply by ●March 12, 20042004-03-12
Wolfgang Allinger wrote:> > On 11 Mar 04 at group /comp/lang/forth in article > <40509B43.DF463F05@yahoo.com> > <spamgoeshere4@yahoo.com> (rickman) wrote: > > >Thanks for the reply. I was aware of some of the history, but not all > >the details. > > > >Rafael Deliano wrote: > >> > >> The short answer: don't bother. > > >If the tools and chips are expensive as you say, I won't bother. I am > >hoping that I can get them for a price in line with other MCUs. The > >problem with other devices is that they are not as low power so that > >it becomes hard to apply a backup battery for them to keep time > >without power applied to the board. I have only found two other > >devices that can implement an RTC from battery at automotive temps. > >One is a Dallas part that includes a thermometer, but they don't spec > >the RTC at the full temp range and the other is the microBuddy from > >Semtech. This one is not "spec'd" over automotive temp range, but > >they publish calibration curves up to 125C and they say it will > >operate. > > > >My incentive to using a different solution is to lower the cost. So > >if the MARC4 EEPROM chips and/or tools come in at a high dollar, I > >will have to forget them. > > You should look at the Cygnal F300 size 3x3mm ! > The F310 is 5x5mm (with the Micro Lead Packages) > They hav a lot of peripherals, including ADC, PWM, temp sensor, UART and > tons of more with a very fast optimized 8051 CPU. 1kB RAM and 8/16kB > Flash... > > Supply 2.7..3.6V, 5mA @ 25MHz, only 11uA @ 32kHz (a typical watch > crystal) and Stop mode with 0,1uA. Temp range -40..+85 degree celsius. > > Do you really need 125C? Try to talk with Cygnal. Are there Crystals > specified for 125C ?Yes, there are crystals spec'd for 125C. The temp coef gives a parabolic shape with the freq slowing at both high and low freqs, so the errors mounts up at 125C... but you can get them. I have not found any other MCUs that will give me RTC operation at <2 uA. This is tough to achieve unless it is a design goal from the start. The Cygnal specs are not good enough and they don't meet the temp requirement. Microchip, Motorola, National and a couple of others make automotive temp MCUs that are close to what I need. None of them are the "perfect" solution or even can run at watch currents when providing RTC functions. So they all require a separate RTC chip.> Oh I forgot, Cygnal is swallowed by Silicon Labs, however > http:\\www.cygnal.com is still working. > > Typical development kit is about 99$. A single additional target board > is 50$. > > BTW I'm using the F310 (in a normal package) together with amrForth (a > free GPL forth!) Their GUI runs under Windoze and Linux! > I use Windoze, amResearch mainly Linux.I am familiar with both the Cygnal (si labs) parts as well as amrForth. But it would be a tough sell to get a vendor to qualify parts outside their normal range. I can't put a part on my board that the vendor can't tell me will work. There are coils, for example, that only spec down to -25C. Normally low temps are not a problem, but they say they can't meet the temp shock tests below -25C. So I am not going to argue with them. I would like to use a Cygnal part as a Dallas 1-wire replacement. But the cost is too high, even for the 11 pin parts. I would need something under $1.50 (industrial temp range, not automotive). I know a lot of people like the Cygnal parts, but I find them over priced for most apps. -- Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX
Reply by ●March 12, 20042004-03-12
Uzytkownik "rickman" <spamgoeshere4@yahoo.com> napisal w wiadomosci news:40514DCB.B658B9A6@yahoo.com...> Brad Eckert wrote: > > > > rickman <spamgoeshere4@yahoo.com> wrote in messagenews:<40509B43.DF463F05@yahoo.com>...> > > I have only found two other devices that > > > can implement an RTC from battery at automotive temps. One is aDallas> > > part that includes a thermometer, but they don't spec the RTC at the > > > full temp range and the other is the microBuddy from Semtech. Thisone> > > is not "spec'd" over automotive temp range, but they publishcalibration> > > curves up to 125C and they say it will operate. > > > > > > My incentive to using a different solution is to lower the cost. Soif> > > the MARC4 EEPROM chips and/or tools come in at a high dollar, I will > > > have to forget them. > > > > Rick "rickman" Collins > > rick.collins@XYarius.com > Ignore the reply address. To email me use the above address with the XY > removed. > > Arius - A Signal Processing Solutions Company > Specializing in DSP and FPGA design URL http://www.arius.com > 4 King Ave 301-682-7772 Voice > Frederick, MD 21701-3110 301-682-7666 FAXHi Try http://www.emmicroelectronic.com/. They have RTC for automotive temp range (V3020,V3021). They also have 4bit MCU (ROM or MTP). Best regards from Poland Jarek
Reply by ●March 12, 20042004-03-12
rickman <spamgoeshere4@yahoo.com> wrote in message news:<40514DCB.B658B9A6@yahoo.com>...> I have not > found any automotive temp QFNs other than the PICs. They don't get down > to this low current, so I would have to use a separate RTC which is what > I am trying to optimize out :)How about Fairchild Semiconductor ACE1502V. http://www.fairchildsemi.com/ds/AC/ACE1502.pdf 1.8V to 3.6V, -40C to +125C operation, but no RTC. Maybe use a CD4060 to produce 2Hz from a watch crystal and bring it out of HALT mode every 1/2 sec. With a run current of 500uA you have a whole millisecond to wake up, update the RTC and halt to get 1uA average from the micro. Halt mode is typically 100nA. One more sanity check: a CD4060 in 16TSSOP is $0.15 on tape and reel from Digikey. --Brad
Reply by ●March 12, 20042004-03-12
rickman wrote:> Thanks for the help. But next time, ask before you send a large file > by email. It is downloading now and I won't be able to receive any > other emails for the next couple of hours or so. > > I wish you had mentioned these chips before when I was posting about > automotive parts. I know they don't fit the profile I was asking > about due to lack of temperature measurement, but I would have liked > to have known they were out there. Being able to run off a 32kHz > xtal and a watch battery is a useful feature. Even the AVRs and PICs > can't do that at <2 uA in the automotive range.Sorry, I guess we are too used to broadband here in Europe... -- Best Regards Ulf at atmel dot com These comments are intended to be my own opinion and they may, or may not be shared by my employer, Atmel Sweden.
Reply by ●March 12, 20042004-03-12
Jarek wrote:> > Hi > > Try http://www.emmicroelectronic.com/. > They have RTC for automotive temp range (V3020,V3021). > They also have 4bit MCU (ROM or MTP).Thanks for the pointer, but I have already seen their MCU products. I have not been able to find any MCUs in their product line that are automotive temp, otherwise they would be perfect! The RTC does not have an alarm output to wake up the MCU, but I might be able to use it anyway. I could let the RTC run on the battery and have an MCU run on the input power only. The MCU would have to read the time each time it powers up and otherwise be pretty low power, but it would not have to be 2 uA. This might work ok, thanks. I still have the issue of price. I'll have to get a price quote. -- Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX
Reply by ●March 12, 20042004-03-12
Wolfgang Allinger wrote:> > On 12 Mar 04 at group /comp/lang/forth in article > <40515133.9ABDB5A9@yahoo.com> > <spamgoeshere4@yahoo.com> (rickman) wrote: > > >I am familiar with both the Cygnal (si labs) parts as well as > >amrForth. But it would be a tough sell to get a vendor to qualify > >parts outside their normal range. I can't put a part on my board that > >the vendor can't tell me will work. There are coils, for example, > >that only spec down to -25C. Normally low temps are not a problem, > >but they say they can't meet the temp shock tests below -25C. So I am > >not going to argue with them. > > However are there Li batteries specified for -40C to 125C?Oh yes. Panasonic has a line of coin cells that are rated over this full range. There is also a movement to provide batteries to use in tires for pressure sensing. These new devices will be rated for -40 to 125C as well. They seem to be just a bit large for my apps though.> >I would like to use a Cygnal part as a Dallas 1-wire replacement. But > >the cost is too high, even for the 11 pin parts. I would need > >something under $1.50 (industrial temp range, not automotive). I know > >a lot of people like the Cygnal parts, but I find them over priced for > >most apps. > > Sadly yes :-(There are other devices, when I get to that point, I will put together a list of all the small MLF devices and pick one. That 11 pin package is really nice and small though. -- Rick "rickman" Collins rick.collins@XYarius.com Ignore the reply address. To email me use the above address with the XY removed. Arius - A Signal Processing Solutions Company Specializing in DSP and FPGA design URL http://www.arius.com 4 King Ave 301-682-7772 Voice Frederick, MD 21701-3110 301-682-7666 FAX
