Raising ATmega8L speed to 16 MHz

[Epegic]

Hi all,

The operating voltage of ATmega8L is 2.7V to 5.5V, speed is 8MHz,
while operating voltage of ATmega8 is 4.5V to 5.5V, speed is 16MHz.

Does that means ATmega8L's low speed is specified for 2.7V and can be saftly raised to 16MHz if using 5.5V operating voltage?

 

[hm_fa_da]

atmega8 vs atmega8l

i don't think so , i think you can use ATmega8L at 8 Mh in 5.5V not at 16Mh.

 

[artem]

avr overclock

There is site where application with overclocked AVR micro decribed - https://www.serasidis.gr/ . But it is not for atmega series.Anyway if you are interrested - you can try .

 

[ME]

atmega overclock

Hi all,

The operating voltage of ATmega8L is 2.7V to 5.5V, speed is 8MHz,
while operating voltage of ATmega8 is 4.5V to 5.5V, speed is 16MHz.

Does that means ATmega8L's low speed is specified for 2.7V and can be saftly raised to 16MHz if using 5.5V operating voltage?

No, it means that ATmega8L is specified for 8 MHz in the full range from 2.7 V to 5.5 V.

On the other hand, I think you can use the ATmega8 at 2.7 V if you lower the speed to max. 8 MHz although this it not specified.

You can overclock ATmegas though, here's an ATmega128 16 MHz overclocked at 24 MHz!: www.elektroda.pl/eboard/viewtopic.php?t=59160&highlight=polish

 

[Epegic]

atmega8 overclocked

I made a simple board and verified that ATmega8L can run at least 22MHz with 5V supply. It meight be my ATmega8L can run at such high frequeccy, and interested to know if it works in general.

If you have ATmega8L chip, see what frequency it can run with 5V supply,
or for ATmega8 chip, how low the voltage can be when running at 8MHz.

Regards,

 

[ME]

atmega8l

I tried to run a ATmega8 at 3.3V 8MHz without problems.
I think ATmega8 and 8L are completely the same device but maybe not tested at the same voltage and speed ranges.
If the device can't run properly when tested at 2.7V 8MHz maybe Atmel stamp it with ATmega8.
On the other hand if a device can't run propely at 4.5V 16MHZ maybe the put the stamp ATmega8L on it.

I know they do the same with PC processors.
I a device can't run at 4 GHz, then they test it at a lower speed, if it works ok they stamp it burn some fuses and stamp the Procesoor with a lower speed range.


Anyway the ATmega8(L) is going to be replaced with ATmega88 which can operate from 1.8 to 5.5 V @ 16 MHz.

 

[ME]

atmega8l running 16mhz

It turns out the new ATmega48/88/168 are faster than other AVR's.
The new devices can run at speeds up to 24 MHz vs. 16 MHz for previous AVR's.

Specs for ATmega48/88/168:

• Operating Voltage:
– 1.8 - 5.5V for ATmega48V/88V/168V
– 2.7 - 5.5V for ATmega48/88/168
• Speed Grade:
– ATmega48V/88V/168V: 0 - 6 MHz @ 1.8 - 5.5V, 0 - 12 MHz @ 2.7 - 5.5V
– ATmega48/88/168: 0 - 12 MHz @ 2.7 - 5.5V, 0 - 24 MHz @ 4.5 - 5.5V

**broken link removed**

 

[Epegic]

overclocking atmega8

Hi, ME

The specification of new Atmegas states 0-12Mhz and you claimed 24Mhz. Are you meaning overclocking. Atmega8L at 5V "can" run in 24Mhz too.

 

[ME]

avr overclocking

Hi, ME

The specification of new Atmegas states 0-12Mhz and you claimed 24Mhz. Are you meaning overclocking. Atmega8L at 5V "can" run in 24Mhz too.

No, you haven't looked at the link then, it's Atmel that claims 24 MHz and not me!
The specifications for the new ATmegas statses 24 MHz!
I have copied the specifications directily from the data sheet for ATmega88!
You don't need to overclock to achive 24 MHz, you just have to use it at voltages between 4.5 and 5.5 V!

Here's the specifications from the data sheet again in case you can't find it yourself (look at the text in bold):
• Speed Grade:
– ATmega48V/88V/168V: 0 - 6 MHz @ 1.8 - 5.5V, 0 - 12 MHz @ 2.7 - 5.5V
– ATmega48/88/168: 0 - 12 MHz @ 2.7 - 5.5V, 0 - 24 MHz @ 4.5 - 5.5V

 

[paps]

atmega128 16mhz at 3.3v

I have ATmega32L running at 11.059200 MHz @ 5v supply. Now am geting baud rate upto 115200.

I mean to say ATmega32L @ 11.059200 MHz: Working!