Klaus Kragelund wrote:> On 5 Maj, 00:32, Joerg <inva...@invalid.invalid> wrote: >> Kvik wrote: >>> On 4 Maj, 21:10, Joerg <inva...@invalid.invalid> wrote: >>>> Glenn wrote: >>>>> On 04/05/12 02.53, Joerg wrote: >>>>>> While looking at a single sideband receiver project that may be coming >>>>>> up I checked the usual suspects for quadrature demodulators. Many won't >>>>>> (technically ...) go much below 100MHz. Some do and I need to be more in >>>>>> the 5-10MHz region. But they are massive guzzlers when it comes to >>>>>> draining the battery. Like this one which slurps a whole watt (!): >>>>>> http://cds.linear.com/docs/Datasheet/5584f.pdf >>>>>> Isn't there anything better out there that hasn't been discontinued? Or >>>>>> do I have to roll my own again? >>>>> How about this one?: >>>>> 12V 50mA (74HC4052 based): >>>>> Direct Conversion HF Receiver with DDS VFO, OH2NLT and OH7SV: >>>>> http://www.nikkemedia.fi/juma-rx1/index-en.html >>>> That's the good old classical way with a very "busy" schematic: >>>> http://www.nikkemedia.fi/juma-rx1/juma-rx1-main-SCH-Rev-E.pdf >>>>> - >>>>> 12V 11mA: >>>>> Very High Performance Image Rejecting Direct Conversion Receivers >>>>> Or how can an 11 ma receiver out perform the world�s best ham >>>>> transceivers?: >>>>> http://www.norcalqrp.org/files/AustinNC2030Presentation.pdf >>>> Almost the same. >>>>> - >>>>> 144MHz All Mode Transceiver: >>>>> http://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmod... >>>> Yikes! Somebody must have been vey patient at the soldering station :-) >>>>> MC1496: >>>>> http://www.onsemi.com/PowerSolutions/product.do?id=MC1496 >>>> You get one lone mixer in a fairly big package, like with the SA612. >>>> After it's all said and done you've got a whole big circuit board full >>>> of stuff. I just won't have that much space in this case. >>>>> - >>>>> More here: >>>>> http://home.pages.at/chirt/Projects/HDR2005/ref/ref.htm >>>> Thanks, Glenn. Unfortunately none of the authors seems to have found a >>>> more integrated solution than the usual concoction of single-part mixers >>>> and logic chips. If I absolutely have to I'll probably use logic chips, >>>> the main reason being that those can now be bought in TSSOP packages >>>> whereas mixers can't be. >>>> -- >>> Why not use a cheap microcontroller, low current like the Cortex M0 >>> NXP series. >>> Simple analog bandpass filter of the incoming signal, syncronize a ADC >>> from a PWM Local Osc generated by the micro, use a low frequency FIR >>> filter to regenerate the shifted down signal from the undersampled >>> output of the ADC. >>> The ADC needs to be triggered with low jitter, but that should be >>> simple. >>> The Cortex M0 can run at full speed below 1mA, add another 1mA for a >>> 1MSa/s ADC. A number of other microcontrollers can do the same, the >>> Cortex is just a very nice part. >> First we'd have to mix it down for that because my signal will be at >> 5-10MHz carrier frequency. Can also be undersampled, of course, but >> that'll cost a little SNR. Which would probably be ok in this >> application, we don't need to be able to hear the grass grow. >> >> Initially I thought about using a PSoC because it already has digital >> blocks for the quadrature oscillator generation. Also switched-capacitor >> blocks which I should be able to "mis-use" as mixers, and then opamps >> for some gain. But I am not a programmer whizkid. Once we get into a >> higher volume project I'll revisit that, possibly a PSoC-3 is the ticket >> here if I disable the uC in there. The on-board ADC capabilities are a >> bit paltry though. >> >> -- > > AFAIC the psoc1 max mixer freq is in tens of kHz whereas the psoc3 can > handle up to 1 MHz. You may be able to use the psoc1 internal analog > bus as a integrated S/H, but I don't think the specs are to your > liking. >Yes, specs are the other reason why I didn't pursue this further right now. Last time I looked at the opamp data I was not too thrilled. It's ok for mundane stuff such as control gear but for sensitive RF processing maybe not. The PSoC-3 has nice digital fliter blocks though, it may be much better than the old ones. -- Regards, Joerg http://www.analogconsultants.com/
Any low power low frequency quadrature receivers?
Started by ●May 3, 2012
Reply by ●May 4, 20122012-05-04
Reply by ●May 4, 20122012-05-04
On 5/4/2012 5:32 PM, Joerg wrote:> Kvik wrote: >> On 4 Maj, 21:10, Joerg<inva...@invalid.invalid> wrote: >>> Glenn wrote: >>>> On 04/05/12 02.53, Joerg wrote: >>>>> While looking at a single sideband receiver project that may be coming >>>>> up I checked the usual suspects for quadrature demodulators. Many won't >>>>> (technically ...) go much below 100MHz. Some do and I need to be more in >>>>> the 5-10MHz region. But they are massive guzzlers when it comes to >>>>> draining the battery. Like this one which slurps a whole watt (!): >>>>> http://cds.linear.com/docs/Datasheet/5584f.pdf >>>>> Isn't there anything better out there that hasn't been discontinued? Or >>>>> do I have to roll my own again? >>>> How about this one?: >>>> 12V 50mA (74HC4052 based): >>>> Direct Conversion HF Receiver with DDS VFO, OH2NLT and OH7SV: >>>> http://www.nikkemedia.fi/juma-rx1/index-en.html >>> That's the good old classical way with a very "busy" schematic: >>> >>> http://www.nikkemedia.fi/juma-rx1/juma-rx1-main-SCH-Rev-E.pdf >>> >>>> - >>>> 12V 11mA: >>>> Very High Performance Image Rejecting Direct Conversion Receivers >>>> Or how can an 11 ma receiver out perform the world�s best ham >>>> transceivers?: >>>> http://www.norcalqrp.org/files/AustinNC2030Presentation.pdf >>> Almost the same. >>> >>>> - >>>> 144MHz All Mode Transceiver: >>>> http://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmod... >>> Yikes! Somebody must have been vey patient at the soldering station :-) >>> >>>> MC1496: >>>> http://www.onsemi.com/PowerSolutions/product.do?id=MC1496 >>> You get one lone mixer in a fairly big package, like with the SA612. >>> After it's all said and done you've got a whole big circuit board full >>> of stuff. I just won't have that much space in this case. >>> >>>> - >>>> More here: >>>> http://home.pages.at/chirt/Projects/HDR2005/ref/ref.htm >>> Thanks, Glenn. Unfortunately none of the authors seems to have found a >>> more integrated solution than the usual concoction of single-part mixers >>> and logic chips. If I absolutely have to I'll probably use logic chips, >>> the main reason being that those can now be bought in TSSOP packages >>> whereas mixers can't be. >>> >>> -- >> >> Why not use a cheap microcontroller, low current like the Cortex M0 >> NXP series. >> >> Simple analog bandpass filter of the incoming signal, syncronize a ADC >> from a PWM Local Osc generated by the micro, use a low frequency FIR >> filter to regenerate the shifted down signal from the undersampled >> output of the ADC. >> >> The ADC needs to be triggered with low jitter, but that should be >> simple. >> >> The Cortex M0 can run at full speed below 1mA, add another 1mA for a >> 1MSa/s ADC. A number of other microcontrollers can do the same, the >> Cortex is just a very nice part. >> > > First we'd have to mix it down for that because my signal will be at > 5-10MHz carrier frequency. Can also be undersampled, of course, but > that'll cost a little SNR. Which would probably be ok in this > application, we don't need to be able to hear the grass grow. > > Initially I thought about using a PSoC because it already has digital > blocks for the quadrature oscillator generation. Also switched-capacitor > blocks which I should be able to "mis-use" as mixers, and then opamps > for some gain. But I am not a programmer whizkid. Once we get into a > higher volume project I'll revisit that, possibly a PSoC-3 is the ticket > here if I disable the uC in there. The on-board ADC capabilities are a > bit paltry though. >Paltry? I think it's a 20-bit ADC.
Reply by ●May 4, 20122012-05-04
On 5 Maj, 00:59, Klaus Kragelund <klausk...@hotmail.com> wrote:> On 5 Maj, 00:32, Joerg <inva...@invalid.invalid> wrote: > > > > > > > > > > > Kvik wrote: > > > On 4 Maj, 21:10, Joerg <inva...@invalid.invalid> wrote: > > >> Glenn wrote: > > >>> On 04/05/12 02.53, Joerg wrote: > > >>>> While looking at a single sideband receiver project that may be co=ming> > >>>> up I checked the usual suspects for quadrature demodulators. Many =won't> > >>>> (technically ...) go much below 100MHz. Some do and I need to be m=ore in> > >>>> the 5-10MHz region. But they are massive guzzlers when it comes to > > >>>> draining the battery. Like this one which slurps a whole watt (!): > > >>>>http://cds.linear.com/docs/Datasheet/5584f.pdf > > >>>> Isn't there anything better out there that hasn't been discontinue=d? Or> > >>>> do I have to roll my own again? > > >>> How about this one?: > > >>> 12V 50mA (74HC4052 based): > > >>> Direct Conversion HF Receiver with DDS VFO, OH2NLT and OH7SV: > > >>>http://www.nikkemedia.fi/juma-rx1/index-en.html > > >> That's the good old classical way with a very "busy" schematic: > > > >>http://www.nikkemedia.fi/juma-rx1/juma-rx1-main-SCH-Rev-E.pdf > > > >>> - > > >>> 12V 11mA: > > >>> Very High Performance Image Rejecting Direct Conversion Receivers > > >>> Or how can an 11 ma receiver out perform the world=92s best ham > > >>> transceivers?: > > >>>http://www.norcalqrp.org/files/AustinNC2030Presentation.pdf > > >> Almost the same. > > > >>> - > > >>> 144MHz All Mode Transceiver: > > >>>http://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmo=d...> > >> Yikes! Somebody must have been vey patient at the soldering station =:-)> > > >>> MC1496: > > >>>http://www.onsemi.com/PowerSolutions/product.do?id=3DMC1496 > > >> You get one lone mixer in a fairly big package, like with the SA612. > > >> After it's all said and done you've got a whole big circuit board fu=ll> > >> of stuff. I just won't have that much space in this case. > > > >>> - > > >>> More here: > > >>>http://home.pages.at/chirt/Projects/HDR2005/ref/ref.htm > > >> Thanks, Glenn. Unfortunately none of the authors seems to have found=a> > >> more integrated solution than the usual concoction of single-part mi=xers> > >> and logic chips. If I absolutely have to I'll probably use logic chi=ps,> > >> the main reason being that those can now be bought in TSSOP packages > > >> whereas mixers can't be. > > > >> -- > > > > Why not use a cheap microcontroller, low current like the Cortex M0 > > > NXP series. > > > > Simple analog bandpass filter of the incoming signal, syncronize a AD=C> > > from a PWM Local Osc generated by the micro, use a low frequency FIR > > > filter to regenerate the shifted down signal from the undersampled > > > output of the ADC. > > > > The ADC needs to be triggered with low jitter, but that should be > > > simple. > > > > The Cortex M0 can run at full speed below 1mA, add another 1mA for a > > > 1MSa/s ADC. A number of other microcontrollers can do the same, the > > > Cortex is just a very nice part. > > > First we'd have to mix it down for that because my signal will be at > > 5-10MHz carrier frequency. Can also be undersampled, of course, but > > that'll cost a little SNR. Which would probably be ok in this > > application, we don't need to be able to hear the grass grow. > > > Initially I thought about using a PSoC because it already has digital > > blocks for the quadrature oscillator generation. Also switched-capacito=r> > blocks which I should be able to "mis-use" as mixers, and then opamps > > for some gain. But I am not a programmer whizkid. Once we get into a > > higher volume project I'll revisit that, possibly a PSoC-3 is the ticke=t> > here if I disable the uC in there. The on-board ADC capabilities are a > > bit paltry though. > > > -- > > AFAIC the psoc1 max mixer freq is in tens of kHz whereas the psoc3 can > handle up to 1 MHz. You may be able to use the psoc1 internal analog > bus as a integrated S/H, but I don't think the specs are to your > liking. > > Regards > > Klausyou can get a dual dpdt switch in 3x3mm qfn maybe one of those as mixer ? -Lasse
Reply by ●May 4, 20122012-05-04
John S wrote:> On 5/4/2012 5:32 PM, Joerg wrote: >> Kvik wrote: >>> On 4 Maj, 21:10, Joerg<inva...@invalid.invalid> wrote: >>>> Glenn wrote: >>>>> On 04/05/12 02.53, Joerg wrote: >>>>>> While looking at a single sideband receiver project that may be >>>>>> coming >>>>>> up I checked the usual suspects for quadrature demodulators. Many >>>>>> won't >>>>>> (technically ...) go much below 100MHz. Some do and I need to be >>>>>> more in >>>>>> the 5-10MHz region. But they are massive guzzlers when it comes to >>>>>> draining the battery. Like this one which slurps a whole watt (!): >>>>>> http://cds.linear.com/docs/Datasheet/5584f.pdf >>>>>> Isn't there anything better out there that hasn't been >>>>>> discontinued? Or >>>>>> do I have to roll my own again? >>>>> How about this one?: >>>>> 12V 50mA (74HC4052 based): >>>>> Direct Conversion HF Receiver with DDS VFO, OH2NLT and OH7SV: >>>>> http://www.nikkemedia.fi/juma-rx1/index-en.html >>>> That's the good old classical way with a very "busy" schematic: >>>> >>>> http://www.nikkemedia.fi/juma-rx1/juma-rx1-main-SCH-Rev-E.pdf >>>> >>>>> - >>>>> 12V 11mA: >>>>> Very High Performance Image Rejecting Direct Conversion Receivers >>>>> Or how can an 11 ma receiver out perform the world�s best ham >>>>> transceivers?: >>>>> http://www.norcalqrp.org/files/AustinNC2030Presentation.pdf >>>> Almost the same. >>>> >>>>> - >>>>> 144MHz All Mode Transceiver: >>>>> http://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmod... >>>>> >>>> Yikes! Somebody must have been vey patient at the soldering station :-) >>>> >>>>> MC1496: >>>>> http://www.onsemi.com/PowerSolutions/product.do?id=MC1496 >>>> You get one lone mixer in a fairly big package, like with the SA612. >>>> After it's all said and done you've got a whole big circuit board full >>>> of stuff. I just won't have that much space in this case. >>>> >>>>> - >>>>> More here: >>>>> http://home.pages.at/chirt/Projects/HDR2005/ref/ref.htm >>>> Thanks, Glenn. Unfortunately none of the authors seems to have found a >>>> more integrated solution than the usual concoction of single-part >>>> mixers >>>> and logic chips. If I absolutely have to I'll probably use logic chips, >>>> the main reason being that those can now be bought in TSSOP packages >>>> whereas mixers can't be. >>>> >>>> -- >>> >>> Why not use a cheap microcontroller, low current like the Cortex M0 >>> NXP series. >>> >>> Simple analog bandpass filter of the incoming signal, syncronize a ADC >>> from a PWM Local Osc generated by the micro, use a low frequency FIR >>> filter to regenerate the shifted down signal from the undersampled >>> output of the ADC. >>> >>> The ADC needs to be triggered with low jitter, but that should be >>> simple. >>> >>> The Cortex M0 can run at full speed below 1mA, add another 1mA for a >>> 1MSa/s ADC. A number of other microcontrollers can do the same, the >>> Cortex is just a very nice part. >>> >> >> First we'd have to mix it down for that because my signal will be at >> 5-10MHz carrier frequency. Can also be undersampled, of course, but >> that'll cost a little SNR. Which would probably be ok in this >> application, we don't need to be able to hear the grass grow. >> >> Initially I thought about using a PSoC because it already has digital >> blocks for the quadrature oscillator generation. Also switched-capacitor >> blocks which I should be able to "mis-use" as mixers, and then opamps >> for some gain. But I am not a programmer whizkid. Once we get into a >> higher volume project I'll revisit that, possibly a PSoC-3 is the ticket >> here if I disable the uC in there. The on-board ADC capabilities are a >> bit paltry though. >> > > Paltry? I think it's a 20-bit ADC. >Yes, but AFAIR if you need any reasonable speed like tens of KSPS it'll drop to much less. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●May 4, 20122012-05-04
On 5/4/2012 7:06 PM, Joerg wrote:> John S wrote: >> On 5/4/2012 5:32 PM, Joerg wrote: >>> Kvik wrote: >>>> On 4 Maj, 21:10, Joerg<inva...@invalid.invalid> wrote: >>>>> Glenn wrote: >>>>>> On 04/05/12 02.53, Joerg wrote: >>>>>>> While looking at a single sideband receiver project that may be >>>>>>> coming >>>>>>> up I checked the usual suspects for quadrature demodulators. Many >>>>>>> won't >>>>>>> (technically ...) go much below 100MHz. Some do and I need to be >>>>>>> more in >>>>>>> the 5-10MHz region. But they are massive guzzlers when it comes to >>>>>>> draining the battery. Like this one which slurps a whole watt (!): >>>>>>> http://cds.linear.com/docs/Datasheet/5584f.pdf >>>>>>> Isn't there anything better out there that hasn't been >>>>>>> discontinued? Or >>>>>>> do I have to roll my own again? >>>>>> How about this one?: >>>>>> 12V 50mA (74HC4052 based): >>>>>> Direct Conversion HF Receiver with DDS VFO, OH2NLT and OH7SV: >>>>>> http://www.nikkemedia.fi/juma-rx1/index-en.html >>>>> That's the good old classical way with a very "busy" schematic: >>>>> >>>>> http://www.nikkemedia.fi/juma-rx1/juma-rx1-main-SCH-Rev-E.pdf >>>>> >>>>>> - >>>>>> 12V 11mA: >>>>>> Very High Performance Image Rejecting Direct Conversion Receivers >>>>>> Or how can an 11 ma receiver out perform the world�s best ham >>>>>> transceivers?: >>>>>> http://www.norcalqrp.org/files/AustinNC2030Presentation.pdf >>>>> Almost the same. >>>>> >>>>>> - >>>>>> 144MHz All Mode Transceiver: >>>>>> http://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmod... >>>>>> >>>>> Yikes! Somebody must have been vey patient at the soldering station :-) >>>>> >>>>>> MC1496: >>>>>> http://www.onsemi.com/PowerSolutions/product.do?id=MC1496 >>>>> You get one lone mixer in a fairly big package, like with the SA612. >>>>> After it's all said and done you've got a whole big circuit board full >>>>> of stuff. I just won't have that much space in this case. >>>>> >>>>>> - >>>>>> More here: >>>>>> http://home.pages.at/chirt/Projects/HDR2005/ref/ref.htm >>>>> Thanks, Glenn. Unfortunately none of the authors seems to have found a >>>>> more integrated solution than the usual concoction of single-part >>>>> mixers >>>>> and logic chips. If I absolutely have to I'll probably use logic chips, >>>>> the main reason being that those can now be bought in TSSOP packages >>>>> whereas mixers can't be. >>>>> >>>>> -- >>>> >>>> Why not use a cheap microcontroller, low current like the Cortex M0 >>>> NXP series. >>>> >>>> Simple analog bandpass filter of the incoming signal, syncronize a ADC >>>> from a PWM Local Osc generated by the micro, use a low frequency FIR >>>> filter to regenerate the shifted down signal from the undersampled >>>> output of the ADC. >>>> >>>> The ADC needs to be triggered with low jitter, but that should be >>>> simple. >>>> >>>> The Cortex M0 can run at full speed below 1mA, add another 1mA for a >>>> 1MSa/s ADC. A number of other microcontrollers can do the same, the >>>> Cortex is just a very nice part. >>>> >>> >>> First we'd have to mix it down for that because my signal will be at >>> 5-10MHz carrier frequency. Can also be undersampled, of course, but >>> that'll cost a little SNR. Which would probably be ok in this >>> application, we don't need to be able to hear the grass grow. >>> >>> Initially I thought about using a PSoC because it already has digital >>> blocks for the quadrature oscillator generation. Also switched-capacitor >>> blocks which I should be able to "mis-use" as mixers, and then opamps >>> for some gain. But I am not a programmer whizkid. Once we get into a >>> higher volume project I'll revisit that, possibly a PSoC-3 is the ticket >>> here if I disable the uC in there. The on-board ADC capabilities are a >>> bit paltry though. >>> >> >> Paltry? I think it's a 20-bit ADC. >> > > Yes, but AFAIR if you need any reasonable speed like tens of KSPS it'll > drop to much less. >True. 20 bits at up to 187 SPS, 16 bits at up to 48k SPS, 12 bits at up to 192k SPS. I know that's not the best, but for an on-board I thought it pretty good.
Reply by ●May 4, 20122012-05-04
John S wrote:> On 5/4/2012 7:06 PM, Joerg wrote: >> John S wrote: >>> On 5/4/2012 5:32 PM, Joerg wrote: >>>> Kvik wrote: >>>>> On 4 Maj, 21:10, Joerg<inva...@invalid.invalid> wrote: >>>>>> Glenn wrote: >>>>>>> On 04/05/12 02.53, Joerg wrote: >>>>>>>> While looking at a single sideband receiver project that may be >>>>>>>> coming >>>>>>>> up I checked the usual suspects for quadrature demodulators. Many >>>>>>>> won't >>>>>>>> (technically ...) go much below 100MHz. Some do and I need to be >>>>>>>> more in >>>>>>>> the 5-10MHz region. But they are massive guzzlers when it comes to >>>>>>>> draining the battery. Like this one which slurps a whole watt (!): >>>>>>>> http://cds.linear.com/docs/Datasheet/5584f.pdf >>>>>>>> Isn't there anything better out there that hasn't been >>>>>>>> discontinued? Or >>>>>>>> do I have to roll my own again? >>>>>>> How about this one?: >>>>>>> 12V 50mA (74HC4052 based): >>>>>>> Direct Conversion HF Receiver with DDS VFO, OH2NLT and OH7SV: >>>>>>> http://www.nikkemedia.fi/juma-rx1/index-en.html >>>>>> That's the good old classical way with a very "busy" schematic: >>>>>> >>>>>> http://www.nikkemedia.fi/juma-rx1/juma-rx1-main-SCH-Rev-E.pdf >>>>>> >>>>>>> - >>>>>>> 12V 11mA: >>>>>>> Very High Performance Image Rejecting Direct Conversion Receivers >>>>>>> Or how can an 11 ma receiver out perform the world�s best ham >>>>>>> transceivers?: >>>>>>> http://www.norcalqrp.org/files/AustinNC2030Presentation.pdf >>>>>> Almost the same. >>>>>> >>>>>>> - >>>>>>> 144MHz All Mode Transceiver: >>>>>>> http://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmod... >>>>>>> >>>>>>> >>>>>> Yikes! Somebody must have been vey patient at the soldering >>>>>> station :-) >>>>>> >>>>>>> MC1496: >>>>>>> http://www.onsemi.com/PowerSolutions/product.do?id=MC1496 >>>>>> You get one lone mixer in a fairly big package, like with the SA612. >>>>>> After it's all said and done you've got a whole big circuit board >>>>>> full >>>>>> of stuff. I just won't have that much space in this case. >>>>>> >>>>>>> - >>>>>>> More here: >>>>>>> http://home.pages.at/chirt/Projects/HDR2005/ref/ref.htm >>>>>> Thanks, Glenn. Unfortunately none of the authors seems to have >>>>>> found a >>>>>> more integrated solution than the usual concoction of single-part >>>>>> mixers >>>>>> and logic chips. If I absolutely have to I'll probably use logic >>>>>> chips, >>>>>> the main reason being that those can now be bought in TSSOP packages >>>>>> whereas mixers can't be. >>>>>> >>>>>> -- >>>>> >>>>> Why not use a cheap microcontroller, low current like the Cortex M0 >>>>> NXP series. >>>>> >>>>> Simple analog bandpass filter of the incoming signal, syncronize a ADC >>>>> from a PWM Local Osc generated by the micro, use a low frequency FIR >>>>> filter to regenerate the shifted down signal from the undersampled >>>>> output of the ADC. >>>>> >>>>> The ADC needs to be triggered with low jitter, but that should be >>>>> simple. >>>>> >>>>> The Cortex M0 can run at full speed below 1mA, add another 1mA for a >>>>> 1MSa/s ADC. A number of other microcontrollers can do the same, the >>>>> Cortex is just a very nice part. >>>>> >>>> >>>> First we'd have to mix it down for that because my signal will be at >>>> 5-10MHz carrier frequency. Can also be undersampled, of course, but >>>> that'll cost a little SNR. Which would probably be ok in this >>>> application, we don't need to be able to hear the grass grow. >>>> >>>> Initially I thought about using a PSoC because it already has digital >>>> blocks for the quadrature oscillator generation. Also >>>> switched-capacitor >>>> blocks which I should be able to "mis-use" as mixers, and then opamps >>>> for some gain. But I am not a programmer whizkid. Once we get into a >>>> higher volume project I'll revisit that, possibly a PSoC-3 is the >>>> ticket >>>> here if I disable the uC in there. The on-board ADC capabilities are a >>>> bit paltry though. >>>> >>> >>> Paltry? I think it's a 20-bit ADC. >>> >> >> Yes, but AFAIR if you need any reasonable speed like tens of KSPS it'll >> drop to much less. >> > > True. 20 bits at up to 187 SPS, 16 bits at up to 48k SPS, 12 bits at up > to 192k SPS. > > I know that's not the best, but for an on-board I thought it pretty good.If it was 16bits up to 192kbps I'd be really happy :-) -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●May 4, 20122012-05-04
On 5/4/2012 7:45 PM, Joerg wrote:> John S wrote: >> On 5/4/2012 7:06 PM, Joerg wrote: >>> John S wrote: >>>> On 5/4/2012 5:32 PM, Joerg wrote: >>>>> Kvik wrote: >>>>>> On 4 Maj, 21:10, Joerg<inva...@invalid.invalid> wrote: >>>>>>> Glenn wrote: >>>>>>>> On 04/05/12 02.53, Joerg wrote: >>>>>>>>> While looking at a single sideband receiver project that may be >>>>>>>>> coming >>>>>>>>> up I checked the usual suspects for quadrature demodulators. Many >>>>>>>>> won't >>>>>>>>> (technically ...) go much below 100MHz. Some do and I need to be >>>>>>>>> more in >>>>>>>>> the 5-10MHz region. But they are massive guzzlers when it comes to >>>>>>>>> draining the battery. Like this one which slurps a whole watt (!): >>>>>>>>> http://cds.linear.com/docs/Datasheet/5584f.pdf >>>>>>>>> Isn't there anything better out there that hasn't been >>>>>>>>> discontinued? Or >>>>>>>>> do I have to roll my own again? >>>>>>>> How about this one?: >>>>>>>> 12V 50mA (74HC4052 based): >>>>>>>> Direct Conversion HF Receiver with DDS VFO, OH2NLT and OH7SV: >>>>>>>> http://www.nikkemedia.fi/juma-rx1/index-en.html >>>>>>> That's the good old classical way with a very "busy" schematic: >>>>>>> >>>>>>> http://www.nikkemedia.fi/juma-rx1/juma-rx1-main-SCH-Rev-E.pdf >>>>>>> >>>>>>>> - >>>>>>>> 12V 11mA: >>>>>>>> Very High Performance Image Rejecting Direct Conversion Receivers >>>>>>>> Or how can an 11 ma receiver out perform the world�s best ham >>>>>>>> transceivers?: >>>>>>>> http://www.norcalqrp.org/files/AustinNC2030Presentation.pdf >>>>>>> Almost the same. >>>>>>> >>>>>>>> - >>>>>>>> 144MHz All Mode Transceiver: >>>>>>>> http://www.qsl.net/va3iul/144MHz%20All%20Mode%20Transceiver/2m_allmod... >>>>>>>> >>>>>>>> >>>>>>> Yikes! Somebody must have been vey patient at the soldering >>>>>>> station :-) >>>>>>> >>>>>>>> MC1496: >>>>>>>> http://www.onsemi.com/PowerSolutions/product.do?id=MC1496 >>>>>>> You get one lone mixer in a fairly big package, like with the SA612. >>>>>>> After it's all said and done you've got a whole big circuit board >>>>>>> full >>>>>>> of stuff. I just won't have that much space in this case. >>>>>>> >>>>>>>> - >>>>>>>> More here: >>>>>>>> http://home.pages.at/chirt/Projects/HDR2005/ref/ref.htm >>>>>>> Thanks, Glenn. Unfortunately none of the authors seems to have >>>>>>> found a >>>>>>> more integrated solution than the usual concoction of single-part >>>>>>> mixers >>>>>>> and logic chips. If I absolutely have to I'll probably use logic >>>>>>> chips, >>>>>>> the main reason being that those can now be bought in TSSOP packages >>>>>>> whereas mixers can't be. >>>>>>> >>>>>>> -- >>>>>> >>>>>> Why not use a cheap microcontroller, low current like the Cortex M0 >>>>>> NXP series. >>>>>> >>>>>> Simple analog bandpass filter of the incoming signal, syncronize a ADC >>>>>> from a PWM Local Osc generated by the micro, use a low frequency FIR >>>>>> filter to regenerate the shifted down signal from the undersampled >>>>>> output of the ADC. >>>>>> >>>>>> The ADC needs to be triggered with low jitter, but that should be >>>>>> simple. >>>>>> >>>>>> The Cortex M0 can run at full speed below 1mA, add another 1mA for a >>>>>> 1MSa/s ADC. A number of other microcontrollers can do the same, the >>>>>> Cortex is just a very nice part. >>>>>> >>>>> >>>>> First we'd have to mix it down for that because my signal will be at >>>>> 5-10MHz carrier frequency. Can also be undersampled, of course, but >>>>> that'll cost a little SNR. Which would probably be ok in this >>>>> application, we don't need to be able to hear the grass grow. >>>>> >>>>> Initially I thought about using a PSoC because it already has digital >>>>> blocks for the quadrature oscillator generation. Also >>>>> switched-capacitor >>>>> blocks which I should be able to "mis-use" as mixers, and then opamps >>>>> for some gain. But I am not a programmer whizkid. Once we get into a >>>>> higher volume project I'll revisit that, possibly a PSoC-3 is the >>>>> ticket >>>>> here if I disable the uC in there. The on-board ADC capabilities are a >>>>> bit paltry though. >>>>> >>>> >>>> Paltry? I think it's a 20-bit ADC. >>>> >>> >>> Yes, but AFAIR if you need any reasonable speed like tens of KSPS it'll >>> drop to much less. >>> >> >> True. 20 bits at up to 187 SPS, 16 bits at up to 48k SPS, 12 bits at up >> to 192k SPS. >> >> I know that's not the best, but for an on-board I thought it pretty good. > > > If it was 16bits up to 192kbps I'd be really happy :-) >Ok, so now I know your definition of paltry ADCs.
Reply by ●May 4, 20122012-05-04
Kvik <klaus.kragelund@gmail.com> wrote:>On 4 Maj, 21:10, Joerg <inva...@invalid.invalid> wrote: >> Glenn wrote: >> > On 04/05/12 02.53, Joerg wrote: >> >> While looking at a single sideband receiver project that may be coming >> >> up I checked the usual suspects for quadrature demodulators. Many won'= >t >> >> (technically ...) go much below 100MHz. Some do and I need to be more = >in >> >> the 5-10MHz region. But they are massive guzzlers when it comes to >> >> draining the battery. Like this one which slurps a whole watt (!): >> > >Why not use a cheap microcontroller, low current like the Cortex M0 >NXP series. > >Simple analog bandpass filter of the incoming signal, syncronize a ADC >from a PWM Local Osc generated by the micro, use a low frequency FIR >filter to regenerate the shifted down signal from the undersampled >output of the ADC. > >The ADC needs to be triggered with low jitter, but that should be >simple. > >The Cortex M0 can run at full speed below 1mA, add another 1mA for a >1MSa/s ADC. A number of other microcontrollers can do the same, the >Cortex is just a very nice part.Sounds like a nice idea. IIRC the ADC on NXP ARM devices can be triggered by a pin as well. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
Reply by ●May 4, 20122012-05-04
On Fri, 04 May 2012 09:39:03 -0700, Joerg <invalid@invalid.invalid> wrote:>miso wrote: >> On 5/4/2012 8:13 AM, Joerg wrote: >>> miso wrote: >>>> On 5/3/2012 7:38 PM, Tim Williams wrote: >>>>> Hell... these days, it's more like... ADC, Hilbert transform, lowpass >>>>> filter. And it'd probably come out way less than a watt. That's kind of >>>>> sad. >>>>> >>>>> Tim >>>>> >>>> >>>> If you have access to the clock, actually 4x the clock, the demod can be >>>> quite simple. Split the sample stream in half, then with those two >>>> streams, alternately multiply by -1. Then you have I and Q channels. >>>> >>> >>> I know, I've done it many times that way using discrete parts. Since the >>> late 80's, pretty much. But that consumes lots of real estate and power. >>> This time I don't have either. >>> >> >> Lots of patents on that scheme. It is really a pity since the scheme is >> totally obvious to those skilled in the art. > > >If such silly patents haven't run out all it takes is proof that you >dunnit 25 years ago and ... poof ... blows it out the water.That and a megabuck or two.
Reply by ●May 5, 20122012-05-05
On Fri, 04 May 2012 11:11:22 -0500, Tim Wescott wrote:> On Fri, 04 May 2012 10:47:31 -0500, Tim Wescott wrote: > >> On Fri, 04 May 2012 08:13:29 -0700, Joerg wrote: >> >>> miso wrote: >>>> On 5/3/2012 7:38 PM, Tim Williams wrote: >>>>> Hell... these days, it's more like... ADC, Hilbert transform, >>>>> lowpass filter. And it'd probably come out way less than a watt. >>>>> That's kind of sad. >>>>> >>>>> Tim >>>>> >>>>> >>>> If you have access to the clock, actually 4x the clock, the demod can >>>> be quite simple. Split the sample stream in half, then with those two >>>> streams, alternately multiply by -1. Then you have I and Q channels. >>>> >>>> >>> I know, I've done it many times that way using discrete parts. Since >>> the late 80's, pretty much. But that consumes lots of real estate and >>> power. This time I don't have either. >> >> You could reduce power (maybe) by using NE612 parts -- but not space, I >> think. > > Come to think of it, I've done this using CMOS switches as the "mixer" > -- > but that was in a spot that could stand being low dynamic range, and it > was at audio-ish frequencies.I've done that using CMOS switches as well, about 19 or 20 years ago. 455kHz with a 74HC4053 running from +/- 5V. I had a ring counter made from 74HC74 flip flops to make the quadrature switching signals for the '4053. This was the last IF in a 30GHz tracking receiver. Regards, Allan
