Can't comprehend Texas Instruments' Error Amplifier.

Discussion in 'General Electronics Chat' started by BlackMelon, May 1, 2016.

  1. BlackMelon

    Thread Starter Member

    Mar 19, 2015
    Hello guys,

    The amplifier, which is used in current mode control of a buck converter, is on page 2 of this link: I want to analyze this because I want to know its transfer function.

    As the attached images, I applied miller theorem to the C3. Its miller capacitance at the output side was so low that it could be neglected. After doing this, I progressed through many many equations and finally got stuck. Could you please help me find its transfer function?

    (Vcc in the image is exactly the same as the Vo in the TI's link)

    Thank you

    PS. If you can give the time-domain relation between Vcc and Vo in the attached picture, I will appreciate.
    PS2. I did all this bcuz I want to understand the peak current mode pwm control. I know that the current mode control is just feeding switching devices' current in addition to the output voltage of the dc-dc converter. So, we can adjust a suitable duty cycle.
    But why there is the word "peak"? How is it different from normal current mode control?