Power Stage MOSFETs Segmentation in Ripple Controlled Step-Down SMPS

2018 ◽  
Author(s):  
Juri Mihhailov ◽  
Marko Koort ◽  
Toomas Rang
Keyword(s):  
Power Stage ◽  
Step Down

scholarly journals Optimized Digital Controllers for Switching-Mode DC-DC Step-Down Converter

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 412 ◽  
Author(s):  
Ghulam Abbas ◽  
Jason Gu ◽  
Umar Farooq ◽  
Muhammad Abid ◽  
Ali Raza ◽  
...  
Keyword(s):  
Least Squares ◽  
Dynamic Performance ◽  
Nonlinear Least Squares ◽  
Optimization Method ◽  
Buck Converter ◽  
Digital Controllers ◽  
Real Zeros ◽  
Power Stage ◽  
Step Down ◽  
Zeros And Poles

In this paper, a nonlinear least squares optimization method is employed to optimize the performance of pole-zero-cancellation (PZC)-based digital controllers applied to a switching converter. An extensively used step-down converter operating at 1000 kHz is considered as a plant. In the PZC technique, the adverse effect of the (unwanted) poles of the buck converter power stage is diminished by the complex or real zeros of the compensator. Various combinations of the placement of the compensator zeros and poles can be considered. The compensator zeros and poles are nominally/roughly placed while attempting to cancel the converter poles. Although PZC techniques exhibit satisfactory performance to some extent, there is still room for improvement of the controller performance by readjusting its poles and zeros. The (nominal) digital controller coefficients thus obtained through PZC techniques are retuned intelligently through a nonlinear least squares (NLS) method using the Levenberg-Marquardt (LM) algorithm to ameliorate the static and dynamic performance while minimizing the sum of squares of the error in a quicker way. Effects of nonlinear components such as delay, ADC/DAC quantization error, and so forth contained in the digital control loop on performance and loop stability are also investigated. In order to validate the effectiveness of the optimized PZC techniques and show their supremacy over the traditional PZC techniques and the ones optimized by genetic algorithms (GAs), simulation results based on a MATLAB/Simulink environment are provided. For experimental validation, rapid hardware-in-the-loop (HiL) implementation of the compensated buck converter system is also performed.

scholarly journals Small-signal transmittances of DC-DC step-down PWM converter in various operation modes

2015 ◽  
Vol 64 (3) ◽  
pp. 505-529
Author(s):  
Włodzimierz Janke
Keyword(s):  
Buck Converter ◽  
Numerical Calculations ◽  
Small Signal ◽  
Pwm Converter ◽  
Operation Modes ◽  
Power Stage ◽  
Step Down ◽  
Averaged Models ◽  
And Control ◽  
Theoretical Considerations

Abstract Small-signal transmittances: input-to-output and control-to-output of BUCK converter power stage working in CCM or DCM mode are discussed. Ideal converter case and converter with parasitic resistances are considered separately. Derivations of small-signal transmittances, based on different approaches to finding the converter averaged models, are presented and the results are compared. Apart from theoretical considerations, some results of numerical calculations are presented.

Rem Study of Current Effect on the Structure of Clean Si(111) Surface

1990 ◽  
Vol 48 (1) ◽  
pp. 306-307
Author(s):  
A. Yamanaka ◽  
H. Ohse ◽  
K. Yagi
Keyword(s):  
The Other ◽  
Current Direction ◽  
Clean Surface ◽  
Current Effect ◽  
Atomic Steps ◽  
Step Bunching ◽  
Terrace Width ◽  
Step Down ◽  
A Current

Recently current effects on clean and metal adsorbate surfaces have attracted much attention not only because of interesting phenomena but also because of practically importance in treatingclean and metal adsorbate surfaces [1-6]. In the former case, metals deposited migrate on the deposit depending on the current direction and a patch of the deposit expands on the clean surface [1]. The migration is closely related to the adsorbate structures and substrate structures including their anisotropy [2,7]. In the latter case, configurations of surface atomic steps depends on the current direction. In the case of Si(001) surface equally spaced array of monatom high steps along the [110] direction produces the 2x1 and 1x2 terraces. However, a relative terrace width of the two domain depends on the current direction; a step-up current widen terraces on which dimers are parallel to the current, while a step-down current widen the other terraces [3]. On (111) surface, a step-down current produces step bunching at temperatures between 1250-1350°C, while a step-up current produces step bunching at temperatures between 1050-1250°C [5].In the present paper, our REM observations on a current induced step bunching, started independently, are described.Our results are summarized as follows.(1) Above around 1000°C a step-up current induces step bunching. The phenomenon reverses around 1200 C; a step-down current induces step bunching. The observations agree with the previous reports [5].

Step-Down Tx Helpful in Refractory Gastroparesis

2006 ◽  
Vol 39 (20) ◽  
pp. 54
Author(s):  
SHERRY BOSCHERT
Keyword(s):  
Step Down
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