Quantization resolution and limit cycling in digitally controlled PWM converters

Peterchev, Angel V.; Sanders, S.R.

doi:10.1109/pesc.2001.954158

Cited by 128 publications

(124 citation statements)

References 7 publications

Supporting

Mentioning

124

Contrasting

Order By: Relevance

“…Beside the cases shown in this paper, Peterchev and Sanders (2001) as well as Peng et al (2004) show further special cases leading to limit cycle oscillations.…”

Section: No Limit Cycle Oscillationsmentioning

confidence: 58%

Challenges and implementation aspects of switched-mode power supplies with digital control for automotive applications

et al. 2016

View full text Add to dashboard Cite

Abstract. Switched-mode power supplies (SMPS) convert an input DC-voltage into a higher or lower output voltage. In automotive, analog control is mostly used in order to keep the required output voltages constant and resistant to disturbances. The design of robust analog control for SMPS faces parameter variations of integrated and external passive components. Using digital control, parameter variations can be eliminated and the required area for the integrated circuit can be reduced at the same time.Digital control design bears challenges like the prevention of limit cycle oscillations and controller-wind-up. This paper reviews how to prevent these effects. Digital control loops introduce new sources for dead times in the control loop, for example the latency of the analog-to-digitalconverter (ADC). Dead times have negative influence on the stability of the control loop, because they lead to phase delays. Consequently, low latency is one of the key requirements for analog-to-digital-converters in digitally controlled SMPS.Exploiting the example of a 500 kHz-buck converter with a crossover frequency of 70 kHz, this paper shows that the 5 µs-latency of a -analog-to-digital-converter leads to a reduction in phase margin of 126 • . The latency is less critical for boost converters because of their inherent lower crossover frequencies.Finally, the paper shows a comparison between analog and digital control of SMPS with regard to chip area and test costs.

show abstract

“…Beside the cases shown in this paper, Peterchev and Sanders (2001) as well as Peng et al (2004) show further special cases leading to limit cycle oscillations.…”

Section: No Limit Cycle Oscillationsmentioning

confidence: 58%

Challenges and implementation aspects of switched-mode power supplies with digital control for automotive applications

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Among these options, a good candidate is the no limit cycle conditions such as presented in [11], which proposes three conditions to be met to eliminate limit cycle in digital controller. Conditions under which no limit cycle exists are listed below.…”

Section: Quantization Resolution and Limit Cyclesmentioning

confidence: 99%

“…In fact, these two conditions are not enough [11] since nonlinearity of the quantizers in the feedback loop may still cause limit cycles in high loop gain. There are two quantizers in the system: ADC and DPWM.…”

Section: Quantization Resolution and Limit Cyclesmentioning

confidence: 99%

Design of low-power high-frequency digital controlled DC-DC switching power converter

Gao

Guo

Lin-Shi

et al. 2008

J. Shanghai Univ.(Engl. Ed.)

View full text Add to dashboard Cite

This paper models a low-power high-frequency digitally controlled synchronous rectifier (SR) buck converter. The converter is a hybrid system with three operation modes. Digital PID controler is used. Key problems such as quantization resolution of digital pulse-width modulation (DPWM) and steady-state limit cycles of digital control switching model power supply (SMPS) are discussed, with corresponding solutions presented. Simulation of a digital control synchronous buck is performed with a fixed-point algorithm. The results show that the described approach enables high-speed dynamic performance.

show abstract

“…As is well known, finding conditions to predict and to eliminate limit cycles, the so-called ripple instability, for these control systems, is an important task. Many authors have detailed various approaches for the exact determination of limit cycles in PWM systems [13][14][15][16]. The use of describing function theory analysis of PWM systems without a reference input is well documented in [7].…”

Section: Introductionmentioning

confidence: 99%

Kepler’s equation and limit cycles in a class of PWM feedback control systems

2010

View full text Add to dashboard Cite

The aim of this paper is to point out some new results concerning the ripple instability in the closed-loop control system using pulse width modulators (PWM), with natural sampling, as power amplifier. The presented analysis, based on the dual-input describing function method and the theoretical framework of Kepler's problem, shows an equivalence between the computation of switching instants of the PWM and the eccentric anomaly of the planet orbit around the sun, giving a simple stability criterion and a sufficient condition for the absence of solutions of the harmonic balance equation and, therefore, the probable absence of limit cycles of a period of a multiple of that characteristic of the modulator. The derived stability criterion, by using the describing function method, is successively compared with the local stability of the closed-loop PWM system for first-and second-order plants. In the first case it has been formally proved that the proposed criterion ensures the local stability of an equilibrium point, while in the second one a Monte Carlo simulation has confirmed that the selection of the modulator parameters, according to the proposed criterion, gives an effective method to avoid limit cycles and to ensure the local stability.

show abstract

Quantization resolution and limit cycling in digitally controlled PWM converters

Cited by 128 publications

References 7 publications

Challenges and implementation aspects of switched-mode power supplies with digital control for automotive applications

Challenges and implementation aspects of switched-mode power supplies with digital control for automotive applications

Design of low-power high-frequency digital controlled DC-DC switching power converter

Kepler’s equation and limit cycles in a class of PWM feedback control systems

Contact Info

Product

Resources

About