Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

sampling frequency for ADC in pic18

Status
Not open for further replies.

kakar133

Member level 2
Joined
Sep 16, 2010
Messages
49
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Location
USA
Activity points
1,579
how to set sampling frequncy for ADC in pic18f452
 

Tahmid

Advanced Member level 5
Joined
Jun 17, 2008
Messages
4,758
Helped
1,792
Reputation
3,576
Reaction score
1,651
Trophy points
1,393
Location
Silicon Valley, California, USA (from Dhaka, Bangl
Activity points
30,543
Hi,
Goto page 183 of the 18F452 datasheet. There, you see a diagram showing how to set the conversion clock. It is from 128kHz FRC to Fosc/2 in different steps. However, you have to be careful that you provide enough acquisition and conversion times, ie, at 20MHz clock, setting Fosc/2 would not be possible, as you need atleast 13Tad time to have proper ADC functioning (check page 290). For best accuracy, I would always go for the slowest, unless I require something faster. You may want to add an RC low-pass filter at the input with 1k resistor and 0.1uF capacitor.

Hope this helps.
Tahmid.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top