In a current-mode SMPS, is error-amp output really constant?

It is said that the error amplifier ouput Veao is a constant value, but I have some doubt. Let's consider the load regulation case as an example.

Assuming the transient load resistance R decreases, then the average inductance current Iav shall increase to make Vo(=R*Iav) remain the same. On the other hand, the duty cycle D(=Vo/Vin) is not changed, since both Vo and Vin are contants. And both the upwards and downwards current rates (m1 and m2, respectively) are not changed, for the same reason. So, in order to make all the requirements above satisfied simultaneously, the only way seems to move the whole current curve up, while keeping D, m1, m2 the same. This way, Veao (no matter with or without the ramp compensation) has to be increased to an appropriate value, and keep there, in the following steady states. Since the gain of the error amplifier is quite large, the voltage of the inverting input node could still be considered equal to Vref.

Re: In a current-mode SMPS, is error-amp output really const

If load change,assume EA output is constant,how to change pulse width to implement PWM function?,so out voltage cann't be stable.

huojinsi,

So you agree with me? I remember the book by A. Pressman says that the Veao will increase at first, then goes back down to its original place in the coming steady states. But I can't figure out how. Shouldn't it keep there?

Added after 5 minutes:

I think I made some mistake on the topic name. What I really mean is "Is it really constant in steady states?" Sorry for the confusion...

Re: In a current-mode SMPS, is error-amp output really const

I don't agree with ur viewpoint.But i consist with u in steady states!