Alan Courtay

March 7, 2016

Quasi-resonant Flyback Converter Simulation

Saber Tutorial

© 2016 Synopsys, Inc. 2

Agenda

• Quasi-Resonant Flyback Converter (AN1326)

–Principles of Operation

–Simulation vs. Measurement

• Accurate Datasheet-Driven Modeling

–Controller Chip

–MOSFET

–Transformer

• Automated Verification

–EMI

– Loss / Efficiency

© 2016 Synopsys, Inc. 3

Vin: 50/60Hz, 88 to 264 Vac

Vout1: 105 V ± 5%

Iout1: 0.1 to 0.35 A

Vripple1: 1%

Vout2: 14 V ± 10%

Iout2: 0.1 to 1 A

Vripple2: 1%

L6565-Based 50W QR ZVS Flyback

© 2016 Synopsys, Inc. 4

Vin: 50/60Hz, 88 to 264 Vac

L6565-Based 50W QR ZVS Flyback

Power Stage

Vds

tCurrents

t

Vr

Vr

Llk&Cd

Lp&Cd

Ipeak

Secondary

Vin

Primary Demagnetization

Ton

Llk+Lp

Cd

Llk+Lp

Vout1: 105 V ± 5%

Iout1: 0.1 to 0.35 A

Vripple1: 1%

Vout2: 14 V ± 10%

Iout2: 0.1 to 1 A

Vripple2: 1%

Discontinuous Conduction Mode

Peak Current Mode Control

© 2016 Synopsys, Inc. 5

Vin: 50/60Hz, 88 to 264 Vac

L6565-Based 50W QR ZVS Flyback

Power Stage

Vds

tCurrents

t

Ipeak

Vin

Ton Toff

Valley

Switching

Vout1: 105 V ± 5%

Iout1: 0.1 to 0.35 A

Vripple1: 1%

Vout2: 14 V ± 10%

Iout2: 0.1 to 1 A

Vripple2: 1%

Vr

Vr

© 2016 Synopsys, Inc. 6

Vin: 50/60Hz, 88 to 264 Vac

L6565-Based 50W QR ZVS Flyback

Power Stage

Vds

tCurrents

t

Ipeak

Vin

Ton Toff

ZVS

Vr

Vin < Vr

Vout1: 105 V ± 5%

Iout1: 0.1 to 0.35 A

Vripple1: 1%

Vout2: 14 V ± 10%

Iout2: 0.1 to 1 A

Vripple2: 1%

© 2016 Synopsys, Inc. 7

Vin: 50/60Hz, 88 to 264 Vac

L6565-Based 50W QR ZVS Flyback

Power Stage

Vds

tCurrents

t

Ipeak

Vin

Ton Toff

Skip Cycle

Vout1: 105 V ± 5%

Iout1: 0.1 to 0.35 A

Vripple1: 1%

Vout2: 14 V ± 10%

Iout2: 0.1 to 1 A

Vripple2: 1%

© 2016 Synopsys, Inc. 8

RCD

Clamp

Output Voltage Regulation Feedback

Vin: 50/60Hz, 88 to 264 Vac

Vout1: 105 V ± 5%

Iout1: 0.1 to 0.35 A

Vripple1: 1%

Vout2: 14 V ± 10%

Iout2: 0.1 to 1 A

Vripple2: 1%

L6565-Based 50W QR ZVS Flyback

Power Stage

Vcc

start-up

self-supply

© 2016 Synopsys, Inc. 9

L6565-Based 50W QR ZVS Flyback

© 2016 Synopsys, Inc. 10

Agenda

• Quasi-Resonant Flyback Converter (AN1326)

–Principles of Operation

–Simulation vs. Measurement

• Accurate Datasheet-Driven Modeling

–Controller Chip

–MOSFET

–Transformer

• Automated Verification

–EMI

– Loss / Efficiency

© 2016 Synopsys, Inc. 11

Current Sense and Primary Voltage

Full Load, Vin = 100 V

4µs 4µs

1V

100V

© 2016 Synopsys, Inc. 12

Current Sense and Primary Voltage

Full Load, Vin = 380 V

2µs 2µs

1V

100V

© 2016 Synopsys, Inc. 13

Current Sense and Primary Voltage

Half Load, Vin = 100 V

4µs 4µs

1V

100V

© 2016 Synopsys, Inc. 14

Current Sense and Primary Voltage

Half Load, Vin = 380 V

2µs 2µs

0.5V

100V

© 2016 Synopsys, Inc. 15

Cycle Skipping / Frequency Foldback

Light Load, Vin = 300 V

5µs 5µs

0.5V

100V

© 2016 Synopsys, Inc. 16

Current Sense and Primary Voltage

Standby, Vin = 380 VBurst Mode

100µs 100µs

0.5V

100V

© 2016 Synopsys, Inc. 17

Agenda

• Quasi-Resonant Flyback Converter (AN1326)

–Principles of Operation

–Simulation vs. Measurement

• Accurate Datasheet-Driven Modeling

–Controller Chip

–MOSFET

–Transformer

• Automated Verification

–EMI

– Loss / Efficiency

© 2016 Synopsys, Inc. 18

Modeling

Controller IC

© 2016 Synopsys, Inc. 19

Modeling

Controller IC

© 2016 Synopsys, Inc. 20

Modeling

Controller IC

Turn-on

Valley detection model

with StateAMS toolBlanking time

model with TLU tool

Frequency foldback

© 2016 Synopsys, Inc. 21

Modeling

Controller IC

Turn-on

Turn-off

Line voltage feedforward

function implemented in MAST

Limits power capability

at high line voltage

© 2016 Synopsys, Inc. 22

Modeling

Power MOSFET

© 2016 Synopsys, Inc. 23

Modeling

Power MOSFET

• DC Characteristics

Characterized

Temperatures

© 2016 Synopsys, Inc. 24

Modeling

Power MOSFET

• DC Characteristics

• Interelectrode Capacitances

© 2016 Synopsys, Inc. 25

Modeling

Power MOSFET

• DC Characteristics

• Interelectrode Capacitances

• Gate Charge Characteristic

© 2016 Synopsys, Inc. 26

Modeling

Transformer

© 2016 Synopsys, Inc. 27

Modeling

Transformer

• Ferrite Core 3C85

–Hysteresis (major and minor BH loops)

–Frequency dependent losses (hysteresis

and eddy currents)

© 2016 Synopsys, Inc. 28

Modeling

Transformer

• Ferrite Core 3C85

–Hysteresis (major and minor BH loops)

–Frequency dependent losses (hysteresis

and eddy currents)

© 2016 Synopsys, Inc. 29

Modeling

Transformer

• Ferrite Core 3C85

–Hysteresis (major and minor BH loops)

–Frequency dependent losses (hysteresis

and eddy currents)

© 2016 Synopsys, Inc. 30

Modeling

Transformer

• Ferrite Core 3C85

–Hysteresis (major and minor BH loops)

–Frequency dependent losses (hysteresis

and eddy currents)

• Core geometry

–Air gap

– Lamination

© 2016 Synopsys, Inc. 31

Modeling

Transformer

• Ferrite Core 3C85

–Hysteresis (major and minor BH loops)

–Frequency dependent losses (hysteresis

and eddy currents)

• Core geometry

–Air gap

– Lamination

• Windings (Cauer - 1D Model)

–Flux leakage

–Frequency dependent loss (skin and

proximity effects)

–Winding capacitances

© 2016 Synopsys, Inc. 32

Modeling

Transformer

• Ferrite Core 3C85

–Hysteresis (major and minor BH loops)

–Frequency dependent losses (hysteresis

and eddy currents)

• Core geometry

–Air gap

– Lamination

• Windings (Cauer - 1D Model)

–Flux leakage

–Frequency dependent loss (skin and

proximity effects)

–Winding capacitances

© 2016 Synopsys, Inc. 33

Agenda

• Quasi-Resonant Flyback Converter (AN1326)

–Principles of Operation

–Simulation vs. Measurement

• Accurate Datasheet-Driven Modeling

–Controller Chip

–MOSFET

–Transformer

• Automated Verification

–EMI

– Loss / Efficiency

© 2016 Synopsys, Inc. 34

© 2016 Synopsys, Inc. 35

LISN

© 2016 Synopsys, Inc. 36

© 2016 Synopsys, Inc. 37

© 2016 Synopsys, Inc. 38

© 2016 Synopsys, Inc. 39

Experiment Editor Basic Tasks

© 2016 Synopsys, Inc. 40

© 2016 Synopsys, Inc. 41

Parallel

Computing

© 2016 Synopsys, Inc. 42

© 2016 Synopsys, Inc. 43

Most dissipative

components

© 2016 Synopsys, Inc. 44

Conduction Losses Switching Losses

© 2016 Synopsys, Inc. 45

Conduction Losses Switching Losses

Rac = 35kΩ added across primary

to account for air gap fringing field

losses

NTC thermistor

adjusted to 2.8Ω

© 2016 Synopsys, Inc. 46

NTC thermistor

adjusted to 2.8Ω

Rac = 35kΩ added across primary

to account for air gap fringing field

losses

© 2016 Synopsys, Inc. 47

Conclusion

• High fidelity models characterized from datasheets

• Automated design verification / regression testing over broad

operating conditions

–Experiment Analyzer

–Fault Injection

–Worst Case Analysis / Extreme Value Analysis

–Statistical variations (Monte Carlo)

• Scalable solution

–Capacity for large designs (network of power converters)

–User or site (company wide) model library management

–Distributed/grid iterative analysis (parametric Vary, Monte-Carlo,

Worst-Case Analysis, Fault)

© 2016 Synopsys, Inc. 48

Thank You

• Flyback design available on Synopsys Forum

• Improved IGBT Tool in 2016.03

Thank you to Sophia LI, Min ZHANG and Balaji EMANDI for their contributions.

Special thanks to Claudio ADRAGNA and Giovanni GRITTI from ST for their valuable feedback.