Operating Voltage

clanuchnik · ‎2003-06-25

Posted on June 25, 2003 at 12:03

Operating Voltage

clanuchnik · ‎2003-06-24

Posted on June 25, 2003 at 06:59

Is there any way to keep the 1% frequency accuracy from the internal RC oscillator when working with a 3 V Battery?

Voltage ranges from 3.3 to 2.4V

I'm using the ST7LITE 05

simonharrison9 · ‎2003-06-24

Posted on June 25, 2003 at 07:15

Hi,

The RCCR1 value is for 3v (25degC), this is given in the flash and eeprom areas - calibrated during ic production.

I'm unsure what level of change you would see at 3.3v and 2.4v

Do you have any reliable external signal in your application that you could use as a reference to perform a re-calibration as required?

There is an apps note in the downloads area detailing calibrating the RC from the mains.

Hope this helps

Regards,

Simon

Anglia

clanuchnik · ‎2003-06-24

Posted on June 25, 2003 at 07:33

Hello Simon ,

My name is Sherman Amir and i am the FAE of STMicro in Arrow .

I am here with my customer and we don't know how we can overcome this problem .

Can we arrange a conference call with you .

Sherman

clanuchnik · ‎2003-06-24

Posted on June 25, 2003 at 07:59

Hello Simon ,

As a reply to your request :

My Application is a stand alone board with a single 3 V battery. Without any external or reliable frequency source.

I calibrate the product with a fresh battery about 3.3 V in the factory then the product goes to the market and it has to keep the calibration accuracy during the whole life of the battery about 2.4V

I don't have the oprtion of recalibration either.

In short I need to keep the 1% accuracy throughout all the voltage range from 3.3 downto 2.4

Writing RCCR1 into the RCCR register after power on reset is not enough.

Thanks................Claudio

simonharrison9 · ‎2003-06-25

Posted on June 25, 2003 at 11:40

Hi,

Do you have any spare IO on your micro?

Also, can the hardware be changed a little?

Simon

clanuchnik · ‎2003-06-25

Posted on June 25, 2003 at 12:02

Hi Simon

I have spare I/O

clanuchnik · ‎2003-06-25

Posted on June 25, 2003 at 12:03

Hi Simon

I have spare I/O

I can still modify the hardware configuration