[SOLVED] Running PIC18f4520 at 3.3V

[shariq92]

Hi all.
I am trying to interface PIC18f4520 with SD Card. I know there are a lot of projects on the topic but my question is,
Can 18f4520 run at 3.3V?
On this page https://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010297 it says that the Operating Voltage is 2 Volts to 5.5 Volts. Same with the datasheet. But on most forums i have read that only the LF controllers work at lower voltages. So which is it?

 

[vincent1971]

Depends on the speed the pic is running....

 

[wp100]

Hi,

If you see the Electrical Characteristics towards the back of the datasheet it details the voltage /frequency and supply voltages on the next page.

From a practical view have used a 4550 with a 16mhz crystal at 5v and 3v3 configured to run as a pickit2 programmer.

Just tested my bench 4520 / lcd using the internal osc at 4mhz and it works fine at 5v and 3v3

 

[paulfjujo]

hello,

and depend also of the voltage level to drive the SD CARD
PIC serie LF are the most compatible with 2V of power supply.
Other PIC with large range of power suplply need to reduce the FOsc to be able to run at 2V of power supply.

 

[shari2643]

No,it won't work.

 "F" series has operating range 4.2V-5V . LF series has voltage range 2v-5.5v

According to datasheet the max freq at which PIC18LF2420/2520/4420/4520 works is based on following

FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz
Note: VDDAPPMIN is the minimum voltage of the PIC® device in the application.

 

[shariq92]

Thank you everyone for answering. I will give it a go. Will post an update soon.