ST7FLITE09Y0M6 / can the PLL by 4 be used at 5v to reduce power cosumption?

[jean-philippe2]

Posted on October 21, 2002 at 22:08

ST7FLITE09Y0M6 / can the PLL by 4 be used at 5v to reduce power cosumption?

[jean-philippe2]

Posted on October 18, 2002 at 07:51

My question concerns the ST7FLITE09 PLL. is it possible to use it (PLL*4) at 5v and which will be the oscillator (Fosc) accuracy ?

The specification mentions PLL*4 can be used between 2.4V and 3.3v but nothing concerning between 3.3v and 5.5v ? I need to reduce the consumption and one way should be to work at 4Mhz !!! thanks JP

[johan239955_stm1_stmicro]

Posted on October 21, 2002 at 22:08

I asked the exact same question few months ago to a ST tech support in France and the response was negative.

At 5V, your only options are either the PLL x 8 or no PLL. However, keep in mind that you can set the RC circuitry at a different calibration than the popular 1MHz. Per the datasheet (see rev 2.2 from Sept 2002, page 81/115), you can get down to 760kHz typ at 25C when RCCR = FFh. And 760kHz times 8 using the Pll gives you 6MHz. It is not the 4MHz but it is better than nothing Regards, Jojo