Bee Technologies Design Kit Flyback Converter using PWM IC LTspice Version 1Copyright (C) Siam Bee Technologies 2015 02JUL2015.

Bee Technologieshttp://www.bee-tech.info/

Design KitFlyback Converter using PWM IC

LTspice Version

1Copyright (C) Siam Bee Technologies 2015

02JUL2015

http://www.bee-tech.info/

http://www.bee-tech.info/

Contents

1. 50W Off-Line Adapter Circuit (VIN=85Vac)1.1) Input Waveform1.2) Output Waveform1.3) Output Power

1.4) Gate Drive Output and Oscillator Timing (IC)2. 50W Off-Line Adapter Circuit (VIN=110Vac)

2.1) Input Waveform2.2) Output Waveform2.3) Output Power

2.4) Gate Drive Output and Oscillator Timing (IC)3. 50W Off-Line Adapter Circuit (VIN=265Vac)

3.1) Input Waveform3.2) Output Waveform3.3) Output Power

3.4) Gate Drive Output and Oscillator Timing (IC)4. Transformer Specification5. Operation Waveform (VIN=110Vac, Example)

5.1) Transformer Turn Ratio5.2) Transformer Primary Side Inductance (LP)

5.3) VCC Output Waveform5.4) MOSFET Switching Device (UQ101)5.5) Output Rectifier Diode (D201 - D202)

5.6) Current Sensing and Feedback Circuit

ConclusionSimulation DetailsAppendix A - Initial Condition SettingsAppendix B - Bill of MaterialsSimulation Index


1. 50W Off-Line Adapter Circuit (VIN=85Vac) - Simulation Circuit


.tran 0 50m 0 10n

.Option Gmin=75E-9

.Option Abstol=1.0E-9

.Option Vntol=1.0u

.Option Trtol=1000

.Option Method=Gear* Engine Solver: Alternate

Initial condition are set ,so the simulation starts near the steady state.

VIN=85VacV(Out) starts from 11V by the initial condition

V(Vcc) starts from 12V

1.1) Input Waveform- Simulation Result

Copyright (C) Siam Bee Technologies 2015 4

Time [sec]

VDC,AVG = 104.33V

VAC = 85VrmsVDC, MIN = 85.8V

1.2) Output Waveform- Simulation Result


The output voltage is regulated at 12.12V

Time [sec]

The output current is 4.04A (RL=3)

V(Out) starts from 11V by the initial condition

1.3) Output Power- Simulation Result


Time [sec]

The simulation result shows the output power is 48.90W

1.4) Gate Drive Output and Oscillator Timing (IC) - Simulation Result


Time [sec]

VOSC

Oscillator frequency = 105kHz

PW = 3.877us



.tran 0 50m 0 10n

.Option Gmin=75E-9


.Option Vntol=1.0u

.Option Trtol=1000



VIN=110Vac





Time [sec]

VDC,AVG = 142.41V

VAC = 110Vrms

VDC, MIN = 128.621V




Time [sec]





Time [sec]




Time [sec]

PW = 3.282us

VOSC




.tran 0 50m 0 10n

.Option Gmin=75E-9


.Option Vntol=1.0u

.Option Trtol=1000



VIN=265Vac





Time [sec]

VDC,AVG = 367.58V

VAC = 265Vrms

VDC, MIN = 361.264V




Time [sec]





Time [sec]




Time [sec]

PW = 1.706us

VOSC


4. Transformer Specification


NP NS

NSUB

Pin (S--F) Turns

NP 1 → 3 54

NS 9 → 12 10

NSUB 5 → 6 10

Winding Specification

Pin Value

Inductance 1 - 3 600uH

Leakage 1 - 3 15uH

Electrical Specification

To model the transformer (or coupled inductors), we can use the SPICE primitive k,

which describes the coupling ratio between a primary and a secondary.

5. Operation Waveform (VIN=110Vac, Example) - Simulation Circuit


+VDS

-

ID

- + VKA

IF

The system parameter are as follows:- Maximum output power : 50W- Input voltage : 110Vrms- AC line frequency : 50Hz- Switching frequency :

100kHz

VIN=110Vac

+

VCC

-

V(Out) starts from 11V


5.1) Transformer Turn Ratio- Simulation Result


Time [sec]

VP

VS

VCC

This figure shows the waveforms of the voltages at each side of the transformer.

This figure shows the waveforms of ID(UQ101) and IF(D201, D202) in the CCM mode.

The primary-side inductance (LP) of the transformer determines the converter operation mode.

5.2) Transformer Primary Side Inductance (LP)

- Simulation Result


Time [sec]

ΟNΤ

Τ

IF(D201, D202)

VPWM

ID(UQ101)

5.3) VCC Output Waveform

- Simulation Result


Time [sec]

VCC = 12.367V

5.4) MOSFET Switching Device (UQ101)- Simulation Result


Time [sec]

VDS(t)

ID(t)

Switching loss (turn-off)

Switching loss (turn-on)

Conduction loss (VDS x ID)

5.5) Output Rectifier Diode (D201 - D202)- Simulation Result


Time [sec]

VKA(t) IF(t)

Peak magnitude current

Conduction loss (VF,AK x IF)

PLOSS_(D201, 202) (t)

5.6) Current Sensing and Feedback Circuit- Simulation Result


Time [sec]

1V Comparator

VCS

Conclusion


Input voltage Output power Oscillator frequency PW

85Vac 48.95 W 105 kHz 3.877 us

110Vac 48.95 W 105 kHz 3.278 us

265Vac 48.70 W 105 kHz 1.706 us

Simulation Results

Simulation Details

Analysis directives:

.Tran 0 50m 0 10n

.Option Gmin=75E-9


.Option Vntol=1.0u

.Option Trtol=1000

.Option Method=Gear

* Engine Solver: Alternate

Libraries:

.LIB 2sk4101ls.lib

.LIB an1431t.lib

.LIB pc817c.lib

.LIB d2sba60.lib

.LIB mbrf20100ct.lib

.LIB era91-02.lib

.LIB 1n5408.lib

.LIB fan7601.lib


Appendix A- Initial Condition Settings


Initial phase= 90

.IC V(Vdc_in)= Vac*√2

.IC V(Vcc)= 12V

.IC V(Out) = 11V

.IC V(Cs)= 0V

.IC V(Rt_Ct)= 0V

.IC V(Ls)= 2V

Appendix B- Bill of Materials


Designator Manufacturer Part Number Comment Designator Manufacturer Part Number Comment

R1 - 10Ω - C109 - 0.47uF -

R103 - 56kΩ - C112 - 0.1uF -

R105 - 100Ω - C201 - 1000uF -

R107 - 0.5Ω - C202 - 1000uF -

R108 - 1kΩ - C203 - 1nF -

R109 - 8kΩ - C222 - 2.2nF -

R110 - 3.9kΩ - D1 Fairchild 1N5408 Spice model



R204 - 27kΩ - D103 Fuji Electric ERA91-02 Spice model

R205 - 7kΩ - D201 ON Semi. MBRF20100CT Spice model

R206 - 10Ω - D202 ON Semi. MBRF20100CT Spice model

C1 - 1nF - U1 Shindengen D2SBA60 Spice model

C103 - 150uF - U101 Fairchild FAN7601 Spice model

C105 - 10pF - UQ101 Sanyo 2SK4101LS Spice model

C106 - 2.7nF - U201 Panasonic AN1431T Spice model

C107 - 47uF - U301 Sharp PC817C Spice model

C108 - 0.01uF -

Simulation Index

30

Simulations Folder name

1. 50W Off-Line Adapter Circuit (VIN=85Vac)................

2. 50W Off-Line Adapter Circuit (VIN=110Vac)..............

3. 50W Off-Line Adapter Circuit (VIN=85Vac)................

4. Operation Waveform (VIN=110Vac, Example)...........

../Simulation data/VIN_85VAC



../Simulation data/Operation Waveform

Copyright (C) Siam Bee Technologies 2015

Bee Technologies Design Kit Flyback Converter using PWM IC LTspice Version 1Copyright (C) Siam Bee Technologies 2015 02JUL2015.

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