How come in some schematics I see many parallel caps? Why don't they combine them into one?
For example, in a TI ADC EVM(ADS5444) schematic it has 3 parts that say "Bypass caps for DRVX" where X goes from 1 to 3 and all are identical. Each one uses 3 different types of caps all in parallel.
1x10uF 10V (polar) 3x0.1uF 16V 3x470pF 50VI assume that this is simply to get the required capacitance in terms of standard values?
If my calculations are correct then the 6 parallel non-polar caps should have an equivilent capacitance of about 0.3uF.
Now this brings up an issue. The 3 pF caps do not really add much capacitance so what are they for? They are rated at 50V but surely at 10V the first cap will go(theoretically) making the others useless? (although maybe they exist for transient reasons?)
Any ideas?
Thanks, Jon