What is the advantage of current mode DCDC modulator

[fantaci]

current mode advantage

What is the advantage of Current mode DCDC modulator compared to voltage mode DCDC modulator.
I thought both structure need saw-tooth wave and similiar compensation. So what is the big deal?

 

[pablomilanes]

current mode dcdc structure

I studied a little about this topic last month. Every structure its own trade-offs. For example:
Using Current Mode Control (cmc) you decrease the degree of your control loop because you are sensing the current at the input the pole associated with the inductor dissapears. Also you have some kind of feedforward control: variations in the voltage input are sensed by the variation in current. In voltage mode control you need to wait until the output senses this variation.
Two papers easy to find in google gives you more understanding:
- Switching Power Supply Topology Voltage Mode vs. Current Mode by Robert Mammano (Unitrode)
- Current-Mode vs. Voltage-Mode Control in Synchronous Buck Converters by Brian Lynch, Texas Instruments Incorporated.

 

[power-twq]

dcdc current mode advantage

current mode DCDC modulator is more stable,

and for the response to input voltage's variation,

a current mode DCDC modulator is faster.


best regards

What is the advantage of Current mode DCDC modulator compared to voltage mode DCDC modulator.
I thought both structure need saw-tooth wave and similiar compensation. So what is the big deal?