这一章介绍峰值电流模控制占空比duty ratio. 也叫current-programmed mode (CPM) 或者 peak current mode (PCM) control. CPM不直接控制duty ratio d(t), 而是通过限制开关管的峰值电流. 控制信号是电流ic(t), 占空比duty ratio d(t)包括电感电流和输出电压取决于ic(t). ic(t)的来源是输出电压和基准Vref经...
Peak current-mode control is preferred by power supply designers because it provides a first-order frequency response characteristic in the control-to-output transfer function. A control-loop design procedure based on the first-order model predicts a phase margin close to 90 degrees. It ...
In a current mode control, the output of the voltage loop provides a command reference for the operation of the current loop. In a closed loop operation, the current loop can be visualized as a mechanism that provides a constant gain between the sensed current and the commanded current. To ...
Current-mode control (CMC) is an extremely popular dc-dc converter loop architecture —and with good reason. Simple operation and dynamics are achieved even though two loops, a wide-bandwidth current loop lurking inside an outer voltage loop, are required. Peak, valley, average, hysteretic, ...
First, the fundamental limitation of average models for current-mode control is identified. The sideband components are generated and coupled with the fundamental component through the PWM modulator in the current loop. Moreover, the switching frequency harmonics cannot be ignored in the current loop ...
关键词: DC-DC power convertors PWM power convertors cascade control compensation control system analysis control system synthesis electric current control feedforward PWM DC/DC power convertors average current mode control 会议时间: 2000/11/01 ...
By the mathematical interpretation of a practical sampler representing the sampling effect of a current control loop, the small signal models of an average current mode control can be easily derived. The instability of the current control loop, which gives rise to the subharmonic oscillation, can ...
A novel small-signal model for current-mode control of PWM (pulse width modulation) converters is extended to the analysis of converters with constant on-time control, constant off-time control, and discontinuous conduction mode (DCM). Constant on or off-time converters in continuous conduction mo...
I decided to choose open-loop peak current mode control, which has simple circuit. Open-loop structure is easy to design, and stable. Microchip’s HV9910B and Diodes AL9910/A are similar open-loop peak current mode controller. They have the same internal circuit and the same pin out, and...
CURRENT-MODE CONTROL Figure 1 shows the two-loop current-mode control system in a typical buck regulator application. A clock signal initi- ates power pulses at a fixed frequency. The termination of each pulse occurs when an analog of the inductor current reaches a threshold established by the...