Primary side control circuit of a flyback converter

Nalepa, Radoslaw; Barry, Noel; Meaney, Paul M.

doi:10.1109/apec.2001.911699

Cited by 45 publications

(11 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead of using feedback loop in output side, the PSR flyback converter senses the auxiliary winding voltage during the turn-off period of main switch to indirectly obtain the output voltage [1]- [3], which is shown in Fig.1. Moreover, lots of single-stage PSR flyback control ICs utilize the auxiliary winding voltage to get the off time of main switch in order to realize power factor correction (PFC) without multiplier [4]- [5].…”

Section: Introductionmentioning

confidence: 99%

Analysis on ringing effect of auxiliary winding in primary side regulated flyback converter

Zhang

Qian

et al. 2014

2014 IEEE Energy Conversion Congress and Exposition (ECCE)

View full text Add to dashboard Cite

The ringing effect in auxiliary winding of transformer, which may cause faulty estimation in primary side regulated flyback converter, is detailed discussed in this paper for the first time. It has been found that: (a) Ringing of auxiliary winding occurs after main switch turns off and is derived from oscillation of the current in primary winding's leakage inductance; (b) This ringing is delivered through the leakage inductance of auxiliary winding. Basis on these discussions, several schemes have been proposed for the design of converter and transformer in order to suppress this ringing effect. Simulation results and experimental results of a singlestage 16-W primary side regulated flyback converter with active power factor correction are given to validate proposed discussion.

show abstract

Section: Introductionmentioning

confidence: 99%

Analysis on ringing effect of auxiliary winding in primary side regulated flyback converter

Zhang

Qian

et al. 2014

2014 IEEE Energy Conversion Congress and Exposition (ECCE)

View full text Add to dashboard Cite

show abstract

“…1 [12]. It is comprised of a bridge rectifier BD, EMI filter, RCD clamp circuit, freewheel diodes D 0 and D 1 , capacitors C 0 and Ca, transformer, power switch M 1 , primary current sensing resistor R CS , pull-up resistor R 1 , pull-down resistor R 2 , and control IC.…”

Section: A System Reviewmentioning

confidence: 99%

Design of a High-Precision Constant Current AC-DC Converter with Inductance Compensation

Chang¹,

Yang²,

Bian³

et al. 2016

Journal of Power Electronics

View full text Add to dashboard Cite

A primary-side regulation AC-DC converter operating in the PFM (Pulse Frequency Modulation) mode with a high precision output current is designed, which applies a novel inductance compensation technique to improve the precision of the output current, which reduces the bad impact of the large tolerance of the transformer primary side inductance in the same batch. In this paper, the output current is regulated by the OSC charging current, which is controlled by a CC (constant current) controller. Meanwhile, for different primary inductors, the inductance compensation module adjusts the OSC charging current finely to improve the accuracy of the output current. The operation principle and design of the CC controller and the inductance compensation module are analyzed and illustrated herein. The control chip is implemented based on a TSMC 0.35μm 5V/40V BCD process, and a 12V/1.1A prototype has been built to verify the proposed control method. The deviation of the output current is within ±3% and the variation of the output current is less than 1% when the inductances of the primary windings vary by 10%.

show abstract

“…To eliminate the opto-coupler from the converter circuit, Nalepa et al [1] suggested using an observer to extract the output voltage from the primary winding voltage. This primary-side sensing idea was then extended to work with an auxiliary winding in [2][3][4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

“…2). In principle, any piece of information contained in V sv from t 2 to t 3 can be used for output voltage extraction [1]. Recent investigations [2][3][4][5][6][7] proposed sampling V sv at the knee point (the time instant t 3 ) which is the moment when the secondary current I 2 drops to zero in DCM or just before the switch turns on in CCM, as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

“…Though an opto-coupler offers a direct and easy way to capture the output voltage, its transfer function is highly nonlinear and dependent on both time and ambient temperature. This drawback imposes an upper constraint on the converter operating temperature, efficiency and size [1]. Therefore, a non-opto-coupler solution is expected to bring a significant improvement for both system performance and production cost.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Primary-side sensing for a flyback converter in both continuous and discontinuous conduction mode

O’Driscoll

Ringwood

2012

IET Irish Signals and Systems Conference (ISSC 2012)

View full text Add to dashboard Cite

-Primary-side sensing is an observer-based approach to estimate the output voltage of flyback converters from a primary winding (or an auxiliary winding). Various observer-laws have been recently developed for flyback converters operating in discontinuous conduction mode (DCM). The extension to continuous conduction mode (CCM), however, has not been considered due to the difficulties in compensating for the voltage drop in the secondary winding. From the possibility to predict the winding voltage drop using the magnetizing current and the transformer model, this paper presents a new observer method that can work accurately and smoothly in both CCM and DCM. The methodology can be combined with any controller to provide either output voltage regulation or output current regulation. The proposed sensing technique is verified by simulation.Keywords -Primary side sensing, flyback converter, continuous conduction mode, discontinuous conduction mode. I IntroductionConventional flyback converters make use of a transformer and an opto-coupler to achieve a galvanic isolation in the power transmission and feedback path, respectively. Though an opto-coupler offers a direct and easy way to capture the output voltage, its transfer function is highly nonlinear and dependent on both time and ambient temperature. This drawback imposes an upper constraint on the converter operating temperature, efficiency and size [1]. Therefore, a non-opto-coupler solution is expected to bring a significant improvement for both system performance and production cost.To eliminate the opto-coupler from the converter circuit, Nalepa et al.[1] suggested using an observer to extract the output voltage from the primary winding voltage. This primary-side sensing idea was then extended to work with an auxiliary winding in [2][3][4][5][6][7][8]. Since Nalepa's approach can be equally applied to either the primary or auxiliary winding, we will concern ourselves with the auxiliary winding, as illustrated in Fig. 1. Where and V o are the converter input and output voltage, respectively. For simplicity, the flyback transformer is exemplified by an ideal model with L m

show abstract

Primary side control circuit of a flyback converter

Cited by 45 publications

References 3 publications

Analysis on ringing effect of auxiliary winding in primary side regulated flyback converter

Analysis on ringing effect of auxiliary winding in primary side regulated flyback converter

Design of a High-Precision Constant Current AC-DC Converter with Inductance Compensation

Primary-side sensing for a flyback converter in both continuous and discontinuous conduction mode

Contact Info

Product

Resources

About