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Author Topic: 8-bit microcontroller without external oscillator??  (Read 6264 times)
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yasir9909
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« on: October 27, 2009, 10:33:38 10:33 »

I am looking for an 8-bit microcontroller without external oscillator and capacitors and could execute at clock frequency of at least 8MHz and better above this frequency.

could anybody recommend me some microcontroller from ATmel,PIC or free scale series that do not require external oscillator and could operate at high speed

Thanks in advance

regards
m.yasir
« Last Edit: October 27, 2009, 10:45:57 10:45 by yasir9909 » Logged

regards
m.yasir
tekniker_erhan
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« Reply #1 on: October 27, 2009, 12:07:15 12:07 »

Pic16f88 have 8 mhz internal calibrated rc oscilator 16f88 run  2mips at 8mhz
Attniy2313 have 8mhz internal calibrated rc oscilator 2313 run 8mips at 8mhz
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flyback
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« Reply #2 on: October 27, 2009, 06:56:16 18:56 »

Please takes a look on the Texas MSP430F2xx serie. They offer an internal oscillator calibrated to +/2%. TI claims that this family run up to 8mips, but I think that a conservative figure of 5 mips is more reasonable. The main advantage is the very low power consumption (under 1uA in standby mode) and a fast wakeup time under 1uS.
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vovchik02
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« Reply #3 on: October 29, 2009, 06:34:18 06:34 »

Pic16F887, Pic18F all model have internal oscillator .
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beque
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« Reply #4 on: October 29, 2009, 05:21:12 17:21 »

The new family PIC16F19XX has an internal oscillator of 32MHz:

http://ww1.microchip.com/downloads/en/DeviceDoc/41364C.pdf
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zorx
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« Reply #5 on: October 29, 2009, 06:06:59 18:06 »

Take a look at MCUs from Silicon Laboratory at

https://www.silabs.com/products/mcu/pages/default.aspx

Wide choice, small package, lots of integrated stuff.
For example, at this moment I'm using C8051F411 model that is in 5x5mm package with integrated oscillator, 12-bit 10-channel 200kS/s ADC with temperature sensor, 12-bit 2-channel current DAC, 21 I/O lines, UART, smaRTClock,  32kB flash, system clock up to 50MHz, supply voltage 2.0-5.25V, .... With 70% of instructions executing in 1 or 2 system clock (speed up to 50MIPS at 50MHz).
If you don't have a problem working with 8051 family, I highly recommend these MCUs in combination with Keil C51.

Regards
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titi
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« Reply #6 on: October 30, 2009, 10:16:40 10:16 »

Hello,

If you want to work with PICs this page may help you to search for good PICs

http://melabs.picbasic.com/Scripts/perl/picsearch.pl?action=adv

To use it:
  Check INTERNAL OSCILLATOR
  Check by exemple :  Device Type FLASH
  Check by exemple :  Speed  24MHz or better
  Check other Characteristics you need
and then press Submit

For each Pic you have the DataSheet.

Best Regards
« Last Edit: October 30, 2009, 10:18:57 10:18 by titi » Logged
tAhm1D
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« Reply #7 on: December 03, 2009, 04:41:14 16:41 »

Hi,
You can use 14 pin PIC 16F684 with 8MHZ internal clock. Very reliable and sturdy. You can try. If bigger size is acceptable, can go to PIC18F series. Lots are available with lot of internal features and with much faster clock speed.
« Last Edit: December 03, 2009, 04:46:20 16:46 by tAhm1D » Logged
rmb1099
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« Reply #8 on: February 08, 2010, 09:44:35 21:44 »

Why this is so important for you?
Can anybody explain the advantage of these Micro. types, pls?
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PilotPTK
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« Reply #9 on: February 08, 2010, 10:11:27 22:11 »

pro's:
less cost - no oscillator/crystal

less board space - no oscillator/crystal

one less failure point.


con's:
Generally not quite as accurate as precision osc/crys



Edit to add:
Depending on the part selected, using the internal osc may lead to lower overall power consumption as well.
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carbontracks
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« Reply #10 on: February 09, 2010, 03:22:25 03:22 »

For certain designs the board space saved with an internal oscillator will be more important than the timing accuracy.

There are tons of mcu's with internal 8MHz oscillators; AVRs, PICs, and TI parts are the first that come to mind.  Anything faster will likely be sophisticated enough that it won't be 8 bit anymore.
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ashu.spect
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« Reply #11 on: February 10, 2010, 07:36:53 07:36 »

Internal Oscillator+8051 Silicon Laboratories is the ways to go and if r in search for a good ADC on board then C8051F350 is the best processor they have in small-form-factor and 8K program memory

hope this info serves ur purpose

Ashu
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wild
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« Reply #12 on: February 10, 2010, 09:34:47 09:34 »

May I suggest the Freescale line of microcontrollers?
Most of them have the internal clock generator.
Their SDK (not free for generating more than 32KB of code) is really good, especially their Processor Expert (Code Bean) feature: it makes REALLY easy to configure/use your internal/external peripherials!

BTW, I'm using the MCS9S08AW line of their microcontrollers and I'm really happy about it: the internal clock (via the FLL) can be set up to 20MHz...
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kayvee
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« Reply #13 on: February 10, 2010, 10:06:12 10:06 »

The new family PIC16F19XX has an internal oscillator of 32MHz:

http://ww1.microchip.com/downloads/en/DeviceDoc/41364C.pdf


I am not aware of one modern 8-bit micro family that does not have an internal oscillator option these days.

These new guys are fantastic, and the PIC16F18xx family too. 


Certainly the price vs. features are great.  Oscillator precision is improving all the while, 1%.  I am sure it won't be long where internal accuracy will rival that of ceramic resonators.
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