Electronic – What are Y5V or Z5U capacitors good for

capacitor

I was thinking decoupling, but you would have to overdimension them because of the high tolerance and temperature stability. And doesn't a 1uF capacitor (instead of 100nF) have the same inductance problems as a 1uF X7R for decoupling?
Are there other applications where the tolerances and variations are so little important that a Y5V or Z5U could be preferred over X5R or X7R? I realize they're somewhat cheaper but that doesn't count if the quality is too bad to be useful, IMO.

Best Answer

I would say the uses can vary depending on your initial project goals/specifications (e.g. what temperature range you want the circuit to perform under, voltage range etc)
You decide the specs/tolerance limits for a particular project, so if you run the numbers and the circuit will function under worst case scenario with slacker tolerance on certain components then all should be well.
This may mean in one project you avoid them completely and in another you use nothing but.
Generally I would agree that they are commonly used as cheap decoupling/bulk capacitance, but there is no reason why you couldn't use them for e.g. a rough timer/oscillator if it still works as intended within your specifications.
Check the datasheet for graphs over temperature, frequency, voltage, etc and decide whether the part will be suitable for a particular use.
Monte Carlo SPICE analysis is a useful tool for determining how a circuit will perform with component variations.