Please, share your professional rules you follow when designing a circuit with several voltage regulators (for example 5V, -5V, +2.5V, -2.5V, 3.3V).
It`s understandable and can be read in datasheet how to operate with one voltage regulator (adding capacitors). But what should one additionally do to have different voltages stable and accurate?
I have decoupling caps at input and output of all LDOs. I use only LDOs, not switched. They are connected this way: (1) 9V => LP2992 => 5V (2) 5V => LP5907 => 3.3V (3) 5V => TLV700 => 2.5V (4) 5V => LP2664 => -5 (5) -5 => NCP4586 => -2.5
I come to this question when I realized that 3 of 5 voltage regulators in my device do its work perfectly, but two voltage outputs from other LDO`s were wrong: 4V instead of 2.5, 1V instead of 3.3.
Also I have decoupling, which is shown on the image (DVDD = 3.3V, AVDD = 2.5, AVSS = -2.5).