Info on resistor and capacitor, tolerance and Power Ratings

[riyazm]

In Embedded Systems we use SMD(Surface Mount Devices) which we use packages such as 0402,0603,0201 etc and has a tolerance of 1%,%5 and power rating of 1/10W,1/16W.For Capacitor has voltage rating of 10V,16V and 25V.

What is the significance in tolerance of i.e the same value with different tolerance and its power rating? for eg: 2.2K,1% and 2.2K 5%
What is the significance its power rating and for capacitor wrt its Voltage rating?
for eg: 0.1uF 10V and 16V

 

[alexan_e]

Depending on where a resistor is used it may be important to use a tolerance as low as possible, for example assume that you are making a voltage divider for the ADC input, you don't want to have +-5% because this will limit the accuracy of the result.
The power rating of resistors and voltage of capacitors should be above the values calculated for each circuit, when you have a resistor connected to a led and consumes 1/4W you can't use a 1/16W device, this is also true for capacitors , the voltage rating should be above the max voltage that will be seen across it while the circuit is working.

Alex

 

[riyazm]

Is it decided wrt to the given power supply?

For ex: My device has a main supply of 5V, then what tolerance should be considered and the package.

 

[alexan_e]

Is it decided wrt to the given power supply?

For ex: My device has a main supply of 5V, then what tolerance should be considered and the package.

What does wrt mean?
You can't decide the parameters of the devices from the power supply of the board.

Alex

 

[riyazm]

wrt- with respect to
Then how it is decided?

 

[alexan_e]

wrt- with respect to
Then how it is decided?

First of all SMS abbreviations are not allowed in the forum so that we can understand each other, consider this a warning for the future.

I have already explained to you that the components are selected based on where they are used, I can give you some magic numbers.

Alex