1
vote
2answers
96 views

Is the value of XTAL load capacitors for ATmega328p @ 16MHz critical?

I'm going to try to assemble an MCU-based circuit using an ATmega328P-PU (Arduino UNO stripped down to essential parts as in this tutorial). I've skimmed over a lot of posts on EE.SE about load ...
4
votes
2answers
98 views

Why use asymmetrical capacitor values for crystal?

Are there any circumstances where you would want asymetrical load capacitors on a crystal? I came across this schematic in the documentation for an NXP UART. It looks just wrong to me. Can anyone tell ...
0
votes
4answers
775 views

Run an atmega328 only using an 16Mhz crystal without caps

Can you run an ATmega328 only using an 16Mhz crystal, so without the capacitors?
5
votes
2answers
227 views

Can a wrong crystal oscilator capacitor burn the MCU?

Short story: I am using an Atmel AT32UC3C2512C MCU and I selected a 20MHz crystal oscillator for it and two NP0 10pF capacitors. I was in doubt between 10pF, 15pF or 22pF, so I decided to start with ...
18
votes
1answer
640 views

What effect does selecting the wrong load capacitance for a crystal have?

I've seen questions such as this one and this one that talk about selecting capacitors that, in series, match up as closely as possible to the load capacitance of the crystal. What effect does ...
4
votes
1answer
145 views

Chosing XTAL Capacitors for Microcontroller

I am trying to chose the parallel capacitors for the crystal on my micro-controller. The crystal is a 9.6MHz quartz crystal (chosen because 9.6MHz is good for UART communication). Going through the ...
5
votes
2answers
207 views

MCU crystal capacitor selection

I will be using the AT32UC3C2512C, the AVR32768 Application note recommends 22pF capacitors for crystals up to 16MHz...I will be using a 20MHz crystal, should I choose a 22pF or a 15pF loading ...
2
votes
1answer
155 views

16MHz Crystal with 2p load capacity: What load capacitors are necessary

I found a nice and cheap crystal on AliExpress which I want to use with my ATMEGA328 microcontroller. Its load capacity is only 2pF. Normally I would say, that the 2 capacitors from the crystal to ...
9
votes
1answer
2k views

Selecting Loading Capacitor Values for 32 kHz Crystal

I need some help selecting loading capacitors for a 32.768 kHz XTAL in a design I'm working on. This is a bit long, but the big questions are: Is it critical to get the loading cap values right, and ...
4
votes
1answer
1k views

Using 22pF load caps with 16MHz crystal on atmega328p fails to work

I'm having a hard time figuring out why after attaching 22pF load caps to a 16 Mhz crystal on atmega328p my whole project (aka flashing leds) does not work. Once i remove the load caps everything ...
2
votes
3answers
637 views

Stray Capacitance for Crystals

I am trying to set up a circuit with a 14.31818MHz crystal (PAL decoding). The data sheet for the chip, using the crystal, states the relationship between the two capacitors, connecting the crystal to ...
10
votes
1answer
7k views

How to design the capacitors used with Crystal Oscillators?

I have seen circuits involving crystal oscillators connecting two capacitors between each of the crystal legs and ground. I would like to know how to design the value of these capacitors for different ...