Join Seminar with Infineon in Shenzhen 25/Aug/06 PowerELab Limited 1 Quality Design for Valued Engineer

Join Seminar with Infineon in Shenzhen 25/Aug/06Join Seminar with Infineon in Shenzhen 25/Aug/06 PowerELab LimitedPowerELab Limited www.PowerESIM.comwww.PowerESIM.com 11

Quality DesignQuality Design

forfor

Valued EngineerValued Engineer


PowerESIM FeaturesPowerESIM Features








SPICE vs PowerESIMSPICE vs PowerESIM

PowerESIM asking for SPICE asking for

K

Np

Ns

Co

Do

M1

Vi

Rp

Rp_ac

Rs

Rs_ac

Rm


PowerESIM is all about - Select and DecisePowerESIM is all about - Select and Decise


Result orientated – Loss analysisResult orientated – Loss analysis

Conversion Efficiency

01020304050607080

70 120 170 220 270

Input voltage RMS (V)

Efficie

ncy (

%)

Measurement

Simulation


Result orientated – Thermal analysisResult orientated – Thermal analysis

Measured

Simulated


Result orientated – Waveform analysisResult orientated – Waveform analysis

Measured

Simulated


Result orientated – Loop Stability & TransientResult orientated – Loop Stability & Transient

1 10 100 1 103

1 104

1 105

200

150

100

50

0

50

100

150

200200

200

Phasei

3 1041 f i

Measured

Simulated


Result orientated – Input Current HarmonicResult orientated – Input Current Harmonic

-0.1

0

0.1

0.2

0.3

0.4

3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39

Harmonic number

Cur

rent

RM

S (A

)

Measured

Class D Limits

Measured

Simulated


Result orientated – MTBF & Life TimeResult orientated – MTBF & Life Time

Simulated

Measured

Will be reported at 1/Mar/2100


Result orientated – DVT reportResult orientated – DVT report

Simulated

Measured


Build a XformerBuild a Xformer

Simulated

Lk=2.982uH

Measured

Lk=2.787uH


Add your own component to all analytical toolsAdd your own component to all analytical tools


Consideration on MOSFETConsideration on MOSFET

Gate drive

Drain voltage

Drain current

t0 t1 t2 t3 t4

t0-t1 drain current catch up with load current

t1-t2 drain voltage falling period

t2-t3 MOSFET fully turn on

t3-t4 drain voltage rising period with miller effect

t4-t5 drain current falling period


Ns Voltage

Diode voltage

Diode current

t1 t2 t3 t4 t5

t0-t1 diode in forward bias

t1-t2 forward current drop to zero

t2-t3 from zero current to peak reverse current (ta)

t3-t4 reverse current droping period

t4-t5 leakage current with reverse voltage

t0

Consideration on DiodeConsideration on Diode


RdcRskin Rskin

Rdc

Rproximity

RcoreRfringe

Ipri ImagIsec

• Rdc – wire dc losses

• Rskin – wire skin effect losses

• Rproximity – wire proximity effect losses

• Rfringe – fringing flux losses

• Rcore – core losses

Consideration of MagneticConsideration of Magnetic


Freq.

Loss

Loss=1W@100kHz

Loss=3W@200kHz

B

Loss

[email protected]

[email protected]

Core Loss Characteristics – Core Loss Characteristics – frequency and fluxfrequency and flux

• Every Engineer know, but . . .


Idc_bias

Loss

D

Loss

Idc_bias

D

Core Loss Characteristics – Core Loss Characteristics – dc bias and duty cycledc bias and duty cycle

• Data sheet Loss is Idc_bias =0

• Large loss @ Idc_bias >Bs

• Somewhere in between must exist rising slope @B

• Higher Freq. higher loss

• Higher flux change rate higher loss

• Smaller D means higher flux change rate


ESR

Irms

Temp.

ESR

ESR=1@25oC

ESR=3@-40oC

Freq.

ESR

ESR=1@100kHz

ESR=2@100Hz

Consideration on CapacitorConsideration on Capacitor


Fm

d(s)

ve(s)

Rs

R s D T s

2 LR s D T s

2 L

-

+

-

+

Cc(s)

Ac(s)Zp(s)

Vi(s)

Vo(s)

iL(s)Bc(s)

++

+

Consideration on Loop AnalysisConsideration on Loop Analysis


By introducing a second order (two pole) transfer functionwith resonate frequency at half of the switching frequencyand a damping factor

2

13

23

2

2

2

ln12

ln

5.05.021

1)(

mm

mm

sssF

swsw

Consideration on Subharmonic InstabilityConsideration on Subharmonic Instability


Fm

d(s)

ve(s)

Rs

R s D T s

2 LR s D T s

2 L

-

+

-

+

Cc(s)

Ac(s)Zp(s)

Vi(s)

Vo(s)

iL(s)Bc(s)

++

+

F(s)

More complicated graphical modelMore complicated graphical model


Automatic compensationAutomatic compensation

• After all, you only need a final compensated design


Consideration on MTBFConsideration on MTBF

p = bArscQET . . .

Where p is the part failure rate

b is the base failure rate

is factors modify the base failure rate


MTBF result with a clickMTBF result with a click


• Consideration on Thermistor

• Consideration on PWM

• Consideration on Bridge:

:

:

• Consideration on Resistor

More Consideration . . . More Consideration . . .


• Drop a business card to me to get one month free trail

Don’t forgetDon’t forget

Documents

Join Seminar with Infineon in Shenzhen 25/Aug/06 PowerELab Limited 1 Quality Design for Valued Engineer