PSRR transfer problem in a system

[langzizhengfan]

Blocks(A,B,C) have PSRR (a,b,c) at DC respectively.How they effect the whole system`s PSRR? In other words, what`s the relationship between them? If I what to improve the whole system`s PSRR, do I have to improve A ,B ,C`s PSRR at the same time? or ……Could anyone give me some information ? Thx

 

[mengcy]

In this system,obviously the power noise injected to A influence the output most .because it's amplified by B loop and C.
power noise injected to C could transmit to output directly.it's less important.
power noise injected to B can be suppressed by the negative feedback system.it's lest important.

 

[langzizhengfan]

In this system,obviously the power noise injected to A influence the output most .because it's amplified by B loop and C.
power noise injected to C could transmit to output directly.it's less important.
power noise injected to B can be suppressed by the negative feedback system.it's lest important.

So can i say that the whole system`s PSRR equal to block A`s PSRR ?