| 摘要 |
Hysteretic performance with fixed frequency may be achieved in controlling a power/voltage regulator, by adapting fixed frequency PWM (Pulse Width Modulation) to current-mode hysteretic control. In steady state, the current waveform may be inferred without having to measure the current. In current-mode control, the current may be adjusted proportional to the error voltage. The change in load current may be related to the change in duty-cycle, and the change in duty-cycle may be related to the error voltage, with the change in duty-cycle expressed as a function of the error voltage, to establish current-mode control. This current-mode control may be adapted to perform current-mode hysteretic, if instead of duty-cycle, the same duty-cycle or current shift was effected by a change in phase. A fraction of ripple current (Forc) may be defined as a specified fraction of the peak-to-peak ripple current, establishing a linear relationship between the Forc and the ripple current. |
