The compensation technology for stability in power IC

[staric]

I want to know how many the compensation technology for stability for power IC. For example, miller compensation and slope compensation and so on. Is there any other compensation technology for stability?

 

[analogic]

lead lag compensation. for 2-stage opamp with first stage cascode, there is a modified miller compensation, refer to razavi's book.
for multi-stage opamp, there r lots of compensation techniques, try to search in IEEE. i remember a professor in hongkong, called T.K. Mok had some good papers on it.

 

[staric]

The stability I mean is about close loop. It used for system. And not for a op circuit.

 

[electronrancher]

slope comp is for current mode ic's only. better to start with voltage mode (simply comparing error voltage to a ramp) because it is more clear.

so there are a few kinds of compensation. if your output cap has a lot of ESR, you get a free low-frequency zero and can use type 2 compensation (1 pole, 1 zero). if you have a low-esr output cap, you need type 3 - (one pole two zeros)

 

[jordan76]

Hi,

I think there are basically two compensation methods:
miller compensation and parallel compensation. Lead lag compensation seems like
a mix of both.

I have no idea of what is slope compensation. Could anyone talk more details about it? Thanks.

regards,
jordan76

 

[muldersun]

In PWM application circuit, there are series R and C at Input of OPAMP, I don't know how to determine the compesation.Anyone can explain it? Thanks!

 

[ambreesh]

Dear jordan76,
YOu could have alook at the following

hope it helps

 

[qutang]

I think the compensation is the most difficult in analog design.

 

[Pavka]

In PWM application circuit, there are series R and C at Input of OPAMP, I don't know how to determine the compesation.Anyone can explain it?

Looks like this circuit leg is used to minimise the op-amp gain at higher frequency to improove the overall closed-loop stability. But also this could be done to introduse a supplementary pole (zero) in the transfer function. It depends on a concrete circuit.

 

[kanbin　]

nested Miller compensation
Use three stage compensation.