1. Designing a 90% efficiency 150W power supply with PFC in hours

2. Next 2.5 hours 2:30 – 2:45 Old vs New 2:45 – 3:15 Active Diode & IC
3:00 – 3:15 EMI Cancellation & IC
3:15 – 3:45 Design Methodology – How we trained?
3:45 – 4:00 Tea Break
4:00 – 4:45 Designed by PowerEsim – New design procedure
4:45 – 5:00 Q&A

3. Old VS
New

4. Old engineer vs Young engineer
20 years ago “
For a MOSFET
Conduction loss = 1/3
Switching loss = 2/3 ”
20 years old “
For a MOSFET
Conduction loss = 2/3
Switching loss = 1/3 ”

5. Old MOSFET VS Young MOSFET
47 ns vs 5 ns, 10 times different

6. How many of them are using ZVS circuit?
Where is the ZVS ?
Adaptor – A efficiency demanding product.
How many of them are using ZVS circuit?

7. Where is the ZVS ? Active Clamp  2 Switch Forward
Full Bridge  Phase Shift Bridge
Asym. Half-Bridge  Half-Bridge

8. Where is the losses?
Example :
82%
10W loss
30 %
10 %
15 %
25 %

9. Where money can buy After all, it is only 10% Pay for ZVS
Pay for lower Rds
Pay for lower tr, tf . .
10 %
After all, it is only 10%

10. Where money can’t buy
Copper & Ferrite
Copper Loss
Band Gap Loss

11. Why not use less copper? Active EMI Filter WT6001 Y-Cap Booster
Next section
Old
New

12. Why not of not using diode?
Old
New
STPS20H100
2*7A 100 deg
TO200 package
USD ?? / pcs
IRF540Z 22m Ohm
14A 100 deg
TO200 package
USD ?? / pcs

13. If TO220 has the same price . . . Active Diode WT6002 active diode IC
Next section
STPS20H100
2*7A 100 deg
TO200 package
USD ?? / pcs
IPP05CN10 5m Ohm
14A 100 deg
TO200 package
USD ?? / pcs

14. Transformer design calculation
After all those mathematics, how will it perform ?

15. Mathematics for the loss
Do you calculate it every time on your design stage?

16. What exactly you are doing?
Np = ?
Co=?
Wire =?
Ns = ?
Wire=?
M1=?
Just simple fill in the blank

17. Transformer – core and wire only
PowerEsim – It is not giving parameters for play with design, It is a tool to build the design.

18. 98% VS 99% - not 1% different
98% efficiency
2% loss
30W loss
99% efficiency
1% loss
15W loss
Efficiency is not just a figure, it does matter.

19. 98% VS 99% - 200% different Selling price double by 1% losses cut
98% efficiency
2% loss
150W converter
99% efficiency
1% loss
300W converter
Selling price double by 1% losses cut

20. What is all about Active Diode vs Diode – almost same cost.
EMI IC vs filter – greatly improve efficiency.
PowerEsim vs Paper design – no cost.

21. Active Diode
&
EMI IC

22. EMI solutions: Passive filter
Conventional EMI solutions depend on passive filter using inductors and capacitors:
Inductors: CMC, DMC
Capacitors: X-cap, Y-cap
There are limitations when using passive filters:
Inductors: Large size and high conduction loss
Capacitors: leakage current specifications

23. Active EMI cancellation IC WT6001: An effective EMI solution – Y-cap booster
A patented technology developed in PowerELab.
An SO-8 IC WT6001 developed with W2.
Equivalent to a Y-cap with very large value within the EMI concerned frequency range only.
No boosting effect in the leakage current test concerned frequency range (50 – 800Hz).
Greatly reduce the common mode inductor size and requirements.
Reduce converter size and improve conversion efficiency.
Provide effective and efficient EMI solution.
Built-in electrical surge protection which can easily pass the EN and EN immunity standard.

24. Applications: Replace passive Y-cap
Replaced by Y-cap booster
LISN

25. Effect measurable by oscilloscope when using Y-cap booster
Noise voltage across Y-cap in
switching converter
Noise voltage across Y-cap booster
in switching converter
More application examples can be found in the datasheet of WT6001

26. Practical application examples
The original EMI filter design cannot pass the EN55022 class B limit.
Filter component:
2 x 20mm high mu toroid for common mode filters
2 x 0.15uF X – cap
1 x 1n Y1-cap connected between primary and secondary

27. Practical application examples: Original filter schematic
It is a commonly used filter configuration
L2B is wound with many turns which intends to suppress the low to mid-frequency common mode noise. Its leakage inductance together with C1 also provides differential mode noise filtering
L1B is a single layer, bi-filer wound common mode choke for high frequency common mode noise filtering

28. Practical application examples: EMI measurement
Y-cap: From 1n to 3n3
DM noise
Improved but not enough
CM noise
Failure was identified to be caused by:
Insufficient leakage inductance of the common mode choke for DM noise attenuation.
The two common mode choke cannot effectively block out the common mode current.
Further increase of Y-cap can reduce CM noise but fail to meet leakage current specifications.

29. Practical application examples: Solution using Y-cap booster
Y-cap booster is used to replace the primary to secondary Y-cap
After using the Y-cap booster, L2B is replaced by a small differential mode filter and L1B is reduced to a 9mm toroid with only a few turns to tackle the high frequency common node noise. The test results pass the required limit lines

30. Practical application examples: Filter comparison: Before and After...
Failed design even with more
cost, loss and bigger size for the
filter
Passed design using Y-cap booster with much smaller filter size that saves cost, power and space

31. Another practical application examples: Filter comparison: Before and After...
Original EMI solution using passive filter
in ATX converter
New EMI solution using Y-cap booster
in ATX converter

32. Conclusion
Y-cap booster breaks the relationship between the Y-cap values and leakage current requirement.
Greatly reduce product design period and resources.
It can be applied to any position with conventional Y-cap.
Significantly reduce the size and loss of common mode choke implies higher power density and efficiency.
EMI less sensitive to transformer winding capacitance implies more rooms for improving transformer coupling.
Very suitable for equipment required low leakage current like medical equipment.

33. Active Diode – An easy to use and high efficiency rectifier suitable for all converters
Stringent requirements of nowadays converters:
Compact size
Low heat generation and high conversion efficiency
High output power and output current
Low cost
………!!!
Conventional technologies cannot meet the requirements!!

34. Synchronous rectifier
Use MOSFETs to replace diode rectifiers.
State of the Art 30V SCK
Average 30V SO8 MOSFET
9 m
0.24 V A K A K
7.8 m

35. Synchronous rectifier
Provides low conduction loss.
Can operate at higher high current without heatsink.
SCK 2.8W 10A
MOSFET 0.7W 10A

36. Synchronous rectifier
Usage not limited to converters with high profit margin.
Price of nowadays low RDSon MOSFETs comparable to schottky diodes using the state of the art technology.
Provide even lower converter cost because of reduced heatsink, more output power, higher conversion efficiency…..
Emerge in low cost converter like adaptors, standard open frame converters, ATX …… .

37. Synchronous rectifierAD AD
Problematic for some conventional topologies
Special and sometimes complicated driving circuits SR
are needed for different topologies
Performance sensitive to transformer leakage
inductance and operating conditions
Converter cannot be paralleled – Reverse current
Poor efficiency at low load
Limited input voltage range
Simple circuit
Discontinuous mode is allowed
Good low load efficiency
Converter can be paralleled
High conversion efficiency
Works just like a diode

38. Active diode – Operating principleK A A1 N1 N2 N3 N4
N1 is the current sense winding
N2 provides MOSFET driving signals
A1 driver circuit (IC WT6002)
N1 N3 & D1 form energy recovery circuit
N4 & D2 form reset circuit D1 D2

39. Active diode – Operating principle
Voltage across winding N2 or
gate drive voltage Von of SR
depends on ratio of N2 to N3
and voltage Vo
Toff Ii A K N1 N2 N3 N4 D1 D2 A1
Von
VN2
Voltage source Vo
can be any voltage
source in a converter,
e.g. output voltage Vo
VN3 Vo
VN4

40. Application of Active Diode in different topologies+ + f + C o V + o
Magnetic
Freewheel
Vin
Reset SR C o V o - S
Vin - -
Flyback SR S
Forward SR -
Flyback
Forward

41. Application of Active Diode in different topologies+ S + + 1 C
SR1 S C 1 1 C V 1
SR1 C o o o
Vin -
Vin + SR 2 - S 2 C S C 2 SR 2 V - 2 2 L - o f2
Half Bridge centre tap
Current Doubler

42. Application of Active Diode in different topologies
SR1 + C V o o - I
SIN
and many others…. SR 2
Resonant converter

43. Successful application of Active Diode in converter products
AD on 150W ACDC
AD on 120W ACDC
AD on 1.5 V 200 A ACDC
AD on 50W ACDC
AD on 300W ACDC
AD on 60W ACDC
AD on 100W DCDC

44. Conclusion A new “Active Diode” technology is presented.
A kind of current driven synchronous rectifier technology that provides high conversion efficiency and eliminates many conventional synchronous rectifier application problems.
Patented technologies.
An Active Diode driver IC WT6002 for easy implementation of the technology.
Well proven by many converter product design.

45. References
Liu, J.C.P.; Poon, F.N.K.; Xuefei Xie; Pong, M.H.; current driven synchronous rectifier with energy recovery sensor Power Electronics and Motion Control Conference, Proceedings. PIEMC The Third International , Volume: 1 , 2000, page(s): vol.1
Xuefei Xie; Liu, J.C.P.L.; Poon, F.N.K.; Man Hay Pong; Current-driven synchronous rectification technique for flyback topology, Power Electronics Specialists Conference, PESC IEEE 32nd Annual , Volume: 1 , 2001, Page(s): vol. 1
Xuefei Xie; Liu, J.C.P.; Poon, F.N.K.; Man Hay Pong; A novel high frequency current-driven synchronous rectifier for low voltage high current applications, Applied Power Electronics Conference and Exposition, APEC Sixteenth Annual IEEE , Volume: 1 , 2001, Page(s): vol.1
Liu, J.C.P.; Xuefei Xie; Poon, F.N.K.; Pong, B.M.H.; Practical solutions to the design of current-driven synchronous rectifier with energy recovery from current sensing, Applied Power Electronics Conference and Exposition, APEC Seventeenth Annual IEEE , Volume: 2 , 2002, Page(s): vol.2
Xuefei Xie; Joe Chui Pong Liu; Poon, F.N.K.; Man Hay Pong; A novel high frequency current-driven synchronous rectifier applicable to most switching topologies, Power Electronics, IEEE Transactions on , Volume: 16 Issue: 5 , Sep 2001, Page(s):
Xie Xuefei; Liu, J.C.P.; Poon, F.N.K.; Pong, B.M.H.; Two methods to drive synchronous rectifiers during dead time in forward topologies, Applied Power Electronics Conference and Exposition, APEC Fifteenth Annual IEEE , Volume: 2 , 2000, Page(s): vol.2
US patent "Current driven synchronous rectifier with energy recovery" patent number 6,134,131
US patent “Self-driven synchronous rectifier by retention of gate charge” patent number 6,377,477
US patent “Current driven synchronous rectifier with energy recovery using hysterisis driver”, patent number 6,597,587

46. fill in a value design a circuit
We are trained to
fill in a value
NOT
design a circuit

47. Fill in values by experience . . .
Vi=100
Vo=12
Vo=Vi*D*Ns / (1-D)*Np
Vi+Vo*Np/Ns=0.8Vds_max
Vo=Ns*0.3*fs/(1-D)
0.5*Vo_ripple=Q/Co
Vds_max_M1=lowerest cost in stock
Ids_max_M1=lowerest cost in stock
IF_max_Do=2*Io
VR_max_Do=1.2*(Vi*Ns/Np+Vo)
Core_T1=recommended table from ferrite manufacturer
Wire_Np=fully filled
Wire_Ns=fully filled

48. Replace 100pcs of components at bench
Then again . . .
Replace 100pcs of components at bench

49. Fine, but no need to replace at the bench . . .
Why not replace 100pcs of components at PowerEsim

50. www.powerEsim.com It’s free It’s on-line It’s for everyone
Worldwide access
100% server side simulation
It’s free

51. Build virtual and real converter
PFC
Developed under
Infineon
TDA4863 Evaluation Design
DC-DC
Developed under
Infineon
ICE3DS01 Evaluation Design
150W 90% LCD Converter

52. 160 W PFC – simulation vs measurement
Input Votlage Vs Efficiency %
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00 85
110
230
265
160W PFC Input Voltage Vac
Measured
PowerEsim

53. 150 W Flyback – simulated vs measured
I/P Votlage Vs Efficiency %
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
300
350
405
150W flybackInput Votlage Vdc
Measured
PowerEsim

54. Loss and Temp.

55. Component Based Approach
Real components
Abstract Concept
Find MOSFET
Find Diode
Find Capacitor
Find Core
Find Wire
Rds*Crss
Vf*trrm CV
k1, k2, k3
Current density

56. PowerEsim vs Traditional Design
PowerEsim turn design into
result oriented adaptive iteration
instead of
skill of knowledge application

57. But first . . .
Find a circuit that has closest specification to your need, e.g. 160W TDA4863 for PFC front end.

58. Ask our expert Enter the input & output specification
Chose an application
Click “Recommend Design”

59. How our expert system work.
Specification
Search for closest evaluation design
Search for best topologies

60. If you like more freedom
Click “Topologies”
Chose the topology you like
Enter the input & output specification

61. Re-define specification
Click “Detail Spec.”
Change specification as you like

62. Click the main MOSFET

63. How we model component?

64. Click, click, click and select
A particular one – total & individual loss
Highlighted one – total, individual loss and stress
Selected one – total individual loss and stress

65. Other than loss, Stress is important

66. More clever method – Smart Optimizer
Click “Select All”
All MOSFET will dump into a optimizer pool

67. Smart Optimizer – just a click
Enter maximum iterations
Wait a few seconds
Click “Smart Optimizer”

68. Multi dimensional optimization
10 resistor 1 x
10 MOSFET 2 x : : x 10
10 diode
= 1010 combination
= 31 years simulation

69. Smart Optimizer – how it work
Data set
Smart Scan
Search for good component
Genetic Algorithm
BU60
BU60
SPD07N60C3
SPD07N60C3
SPN04N60C2
SPN04N60C2
SPB07N60S5
SPB07N60S5
IPP50R520CP
IPP50R520CP

70. Sorted one by one Result will be ranked Click to view each result
Optimized Component will be shown

71. Now Active Diode
Click the diode you like to replace by Active Diode or Sync Rect.
In the Component Finder, change it’s “Rectifier Type” to Active Diode

72. Search more MOSFET Extend to higher current range is usually needed
Extend the body diode’s trrm can find more MOSFET

73. Select a better Sync Rect.
0.5W Active Diode loss
2.54W SCK loss

74. Which component is more critical?
Why M1, D3 & T1
Loss Analysis – the most useful page
It rank the loss and it’s details

75. Follow the step Follow the tips from the header is a good practice.
Just click the box, it will redirect you to other tools
Go through each box step by step

76. Click T1 and go to Magnetic Builder

77. Step 1 – select the core you like
Chose the range of Ae
Select Core shape
Select Manufacturer

78. Instant preview winding when thing change
Click the “preview winding”
Corresponding winding cross section will be shown
Supported on Core, N and Wire.

79. Step 2 – find the best Lm Click the “Inductance” button
Enter the range of inductance
Highlight each in the list, select according to total loss and stress.
Double check OCP is not be triggered.

80. Step 3 – find the best N0 Click the “Number of turn” button
Enter the range of turn
Highlight each in the list, select according to total loss and stress.
Double check OCP is not be triggered.

81. Don’t forget preview winding
Click the “Preview Winding” button
Observe how winding structure change with number of turn.

82. Step 4 – need more copper? Click the “Change Wire” button
Click the “No. of Parallel Wire”
Add more parallel wire as you like.

83. 160 W PFC – simulation vs measurement
Input Votlage Vs Efficiency %
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00 85
110
230
265
160W PFC Input Voltage Vac
Measured
PowerEsim

84. 150 W Flyback – simulated vs measured
I/P Votlage Vs Efficiency %
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
300
350
405
150W flybackInput Votlage Vdc
Measured
PowerEsim

85. DVT – check the stresses
DVT Report check every components stress and also circuit design constraint.

86. Thermal – knowing Temp. at day 1

87. MTBF – how long it last

88. Designing a 90% efficiency 150W power supply with PFC in minutes
Live Demonstration