Design a Champion AC Adapter

Jeffrey Hwang10 min to design your power supply (V)

1

Design a

Champion AC Adapter

Jeffrey H. Hwang

CM6805/CM6806/CM6201/CM6202


2

CM6805/CM6806/CM6201/CM6202

Championand

FairChild

Two Sources:


3

CM6805/CM6806/CM6201/CM6202

4


CM6805 + CM6202100W AC Adapter with SR and without SR

Efficiency vs. VinWith 442uH(RM8)at fsw = 67.5Khz

100W AC AdapterEfficiency with and without SR

Po = 100W

84

86

88

90

92

80 130 180 230

Vin (Vrms)

Effi

cien

cy (%

)

without SR

with SR

CM6805 + CM6202

Measure the Efficiency Data at the end of cables.

5

Jeffrey Hwang10 min to design your power supply (V) CM6805/CM6806/CM6201/CM6202

Average Sale Price ~ US $ 0.65for

Champion AC Adapter SolutionCM6805 (10 pin) + CM6202 (16 pin)

6


High Density AC Adapter

The Challenge: High Efficiency at Low Line (90VAC)

7


Typical Power vs. Efficiency

8


High Density AC Adapter


9

CM6805/CM6806/CM6201/CM6202

How to increase the Efficiency?(Rule of Thumb)

• Full Load due to Conduction Loss = I x I x R:

1. Spend the money to reduce R such as reduce Rdson of Mosfet

2. Reduce I by increasing VIN

• Light Load due to Switching Loss = fsw x C x V x V:

1. Reduce C

2. Reduce V = ZVS

3. Reduce fsw => Green Mode

10

Jeffrey Hwang10 min to design your power supply (V) Full Load Condition Analysis

Failure Rate Vs. Temperature

11


It is desired to have a uniform Surface Temperature for Convection and Radiation

By Proper Layout/Package/Enclosure

12


Maximum Power Dissipation vs. Shape


13


The Maximum Output Power vs. Shape

h , Po

h , Po


14


Use the better Core Shape


Due to the smooth surface, it has the better heat convection


15

Full Load Condition Analysis

A Good AC Adapter Layout

Keep the temperature uniform through out the board


16


36W Fly Back AC Adapter Experimental Result

Design a Flyback Converter

17


36W Fly Back AC Adapter Experimental Result


η~85.6% @ 90VAC with full load

18


How To Improve Flyback Transformer Power Loss?

1. Reduce the n, Turn Ratio to reduce the Secondary Peak Current

• When n ,Ip ,Is , D , Lm , Ls , then Maximum Secondary Voltage .

• When n , Ip , Is , D is , Lm , Ls ,then Maximum Secondary Voltage .

2. Increase the Flyback input voltage3. Use the better RM core instead of EPC core

Design Flyback Converter

19


How To Improve Flyback Transformer Power Loss?


20


How To Reduce Flyback Diode Rectifier Power Loss?

• Increase the Flyback input Voltage

• Use SR, Synchronous Rectification + DCM

• Reduce the secondary current by reducing n, the turn

ratio of Transformer (This will increase Mosfet Loss.)



21




Use a Synchronous Rectifier

22




CCM + Synchronous Rectification has the lower efficiencydue to Trr, body diode recovery issue

23




CCM + Synchronous Rectification has Trr, body diode recovery issue

24





25





DCM Efficiency vs. Input voltage

86%,Efficiency @ 200V, Vin


26





Solution:

•Use DCM + SR, Synchronous Rectifier + Vin >200V + Reduce n


27





Solution:Use DCM + SR, Synchronous Rectifier + Vin > 200V + Reduce n

Load=3A / Fans

75.00%

80.00%

85.00%

90.00%

60 80 100 120 140 160 180 200 220 240 260 280

Input Voltage

Effici

ency Only Schottky

Only SR

SR+Schottky

28


How To Improve Flyback MOSFET Power Loss?

• Increase the Flyback input voltage so conduction loss can be reduced due to D drops.

• Using DCM to prevent the Trr, diode reverse current issue

• Use a lower Rdson Mosfet• Use ZVS


29


Conventional Flyback Converter:


LC tank’s C is due to S1and

It is very small, so Ring frequency

(resonant frequency) is high.

30


Conventional Flyback Converter:


Vds,S1

Ip

The Energy Stored in leakage inductor is wasted in the ringing.

resonant f is high so it is difficult to control (manufacture control) it.

31


ZVS Flyback Converter: Active Clamp


LC tank’s C is due to Cclamp~1uFand

It is relative big, so Ring frequency

(resonant frequency) is lower.

32




No RingandZVS

The energy is stored in the core;release to the input

33




No RingandZVS

34




4.5% Improvement

35




4.5% Improvement due to:•Energy in leakage L and Snubber is saved (Clamped)•Energy in Vds-parasitic capacitor is saved (ZVS)

However, it is expensive:• It needs a high side driver, an extra high side Mosfet

and a simple control circuit• Can we do it without additional cost?


36


ZVS Flyback:Secondary Synchronous Rectifier

with CM6201/CM6202 (smart driver)


LC tank’s C becomes to Co/(n x n)~25uF to 50uF

andIt is big,

so Ring frequency (resonant frequency) is very

low.


37


ZVS Flyback:Secondary Synchronous Rectifier

with CM6201/CM6202 (smart driver)


Benefits:• It does not need high side driver and high side mosfet

• Synchronous Rectification at DCM

Fly back full load Efficiency is increased from

~92% to~92.5% at Flyback input=220V


38


Summary:designing Flyback Converter @ full load & Vin=200V


Without additional cost: Efficiency~92.5% @Full load•Vin >= 220V (with PFC-PWM combo CM6805/06/CM6903)…. Δη =3%• n, turn ratio = 5 or 6….Reduce Is peak current• Full load at DCM but approach to CCM….remove Trr• ZVS by controlling LC variation….Δη=1.5%

With additional cost: Efficiency~94.5% @Full load• Secondary Synchronous Rectifier +ZVS: (CM6201) # Total additional Δ$~ $0.3 at high volume…. Δη=2%• RM 6 or RM 8 core #Δ$ ~$0.2 at high volume….. Δη=1.5%• ZVS Active Clamp at primary side….Δ$ ~$0.8 with Δη=2%

Without the proper design, efficiency could be below 80%.

39


Design a Follower Boost PFC

Choose Follower Boost InductorCM6805 family vs. CRM, 6561

• L ↑, Efficiency ↑• For CRM, 6561, it cannot increase boost inductance.

1. L↑, frequency needs to go lower and it can go below 20Khz2. Ton=2 x L / Rin; for a given load, Ton is a constant3. L ~ 471uH cannot go higher for the Po = 100W 4. Ipeak = Iin Peak x 2 (I x I x R is big; efficiency is poor!)5. At high line and light load, frequency can go above 400Khz (EMI

issue is severe.)• For CM6805/CM6806/CM6903 fixed switching frequency=67.5Khz,

1. Lcm6805 family ~ Lcrm (67.5khz) x 2 (Optimal Inductance Value)2. Lcrm ~ 192uH @ 90VAC and Vout=200V3. Loptimal = 384 uH @ 100W to L= 256 uH @150W4. L ↑, Efficiency ↑5. Both the cost of Boost Mos and Boost Rectifier can be reduced

40


Power Dissipation in Boost Diode


41


Power Dissipation in Boost Mosfet

Dominated One


42



4.5% Improvement

43


PFC Boost with 380V only


44


Continuous Boost Follower

Added Circuit

VlineDC needs to be closed to Dc and > = 5V.

4.5% Improvement….cost~$0.03


45


Two Level Boost Follower (Q1 on, 200V @ low line and Q1 off 380V @ high line)

4.0% Improvement….cost~$0.02

Added Circuit

VlineDC @ high line will turn off Q1 and @ low line will turn on Q1.


46


Two Level Boost Follower or

Continuous Boost Follower

4.0% to 4.5% Efficiency Improvement….cost~$0.02 to $0.03


47


η=91.37%, Vin=90VAC, Po=1KW

2%

MOSFETMOSFET

MOSFET

Boost Power Dissipation Breakdown

Boost 400V Cap


1%

48


η=91.37%, Vin=90VAC, Po=1KW


49


PFC Boost Rectifier Trr issue


50


Use SiC to solve PFC Boost Rectifier Trr issue

Δη~0.5%Δ$~$1.0


51


SiC will help if the frequency is high.


52


SiC will help if the frequency is high.


With Po=100W and Vo=200V for the boost followerfsw = 67.5Khz, Difference Pi=0.05W; Difference

Efficiency=0.042%fsw = 130Khz, Difference Pi=0.2W; Difference Efficiency=0.167%fsw=150Khz, Difference Pi=0.05W; Difference Efficiency=0.042%

With Po=100W and Vo=360V for the regular boostfsw = 67.5Khz, Difference Pi=0.08W; Difference

Efficiency=0.067%fsw = 130Khz, Difference Pi=0.31W; Difference Efficiency=0.254%fsw=150Khz, Difference Pi=0.45W; Difference Efficiency=0.366%

53


Use Soft Switching to solve Trr issue


54


Use Soft Switching to solve Trr issue

Δη=2%Δ$~$1.3@200W


Δη<0.5%Δ$~$1.3@100W

55


Bridgeless PFC


56


Bridgeless PFC

Δη=0.5%......Δ$~$0.5


57


Efficiency Improved due to LETE


58


Efficiency Improved due to LETE


59


CM68XX

CM68XX

Δ$ = -0.1 at no cost…Δη=1% with LETE


60



Without Cost: Efficiency~93.2% @full load•Lboost = 2 x Lcrm (r=1) …. Δη~3%

•2 level Boost Follower(220V/380V)….Δη~4%•CM6805/CM6806/CM6903…. Δη~1%

Summary:design a Boost PFC @ full load and Vin=90Vac

With Cost: Efficiency~95% @full load•SiC…. Δ$~1.0 and Δη~0.5%

•Soft Switching…. Δ$~1.0 and Δη~0.5%•Bridgeless PFC…. Δ$~1.0 and Δη~0.5%


61

•Without Additional Cost (CM6805/CM6806/CM6903):Efficiency~86.1% @full load & Vin = 90VAC

η pfc x η flyback = 93.2% x 92.4%= 86.1%



Summary:Design a Champion AC Adapter @ Full Load and Vin=90Vac

Po=100W

•With Δ$~$0.3 (CM6202):Efficiency~88% @full load & Vin = 90VAC

η pfc x η flyback = 93.2% x 94.5%= 88%

•With Δ$~$3.3 :Efficiency~90.2% @full load & Vin = 90VAC

η pfc x η flyback = 95% x 95%= 90.2%

62


Green Mode

No Load Pi < 0.3WCM6805/CM6806/CM6903

The Best Way

to Save Energy

is to “Turn Off”

Your Appliance

Light Load Efficiency ↑, Goes up, as fpwm↓, Goes down

63


Green Mode

No Load < 0.3 WCM6805/CM6806/CM6903

User Defined GMth, Green-Mode Threshold


64


CM6805/CM6806/CM6903 Build-In Green Mode Functions

No Load Pi < 0.3 WCM6805/CM6806/CM6903

•Reduce the switching frequency when the load is light

•Turn off PFC @ GMth

•Bleed Resistor can be 2 Mohm or higher

without influence the turn-on time

•Reduce operating current


65


Green Mode



66


The Timing Diagram of fRtCt = 2 x fPWM = 4 x fPFC in CM6805, CM6806 and CM6903

CLK

RTCT

TIME

TIME

TIME

280K Hz

280K Hz

140K HzPWMCLK=Maximum

PWM Duty Cycle

Exactly 50%

No Jitter

TIME

TIME

70K Hz

70K HzPFCCLK

PFC Modulation Ramp

fRtCt

fpwmCM6805

fPFC

fpwmCM6806

Pulse Skipping from the controller



67


280K Hz TIME

280K Hz

CLK

TIME

RTCTPin 7

140K HzPWMComparatorOutput

TIME

TIME

PWM DutyCycle 140K Hz

No Jitter

Exactly 50% 140K HzMaximum

TIME

PWMCLK=

PWM Duty Cycle

PWM Green Mode Pulse Skipping Timing Diagram

70K Hz/

70K Hz/

70K Hz/



68


Light Load Efficiency ↑, Goes up, as V↓& fpwm↓, Goes down


Turn Off PFC!When Load is below

Green Mode Threshold, GMth

69




Po=100W Design for V+I pin and PWMtrifault

70




Spread Sheet for the PWM Design for a FlyBackCM6805/CM6806 PWM SECTION for FlyBack Design User Inputs All Resistors, inductor and VCC Units User Inputs the Optical Couple Current and VCC Units

If the cell is filled with yellow color, it is a user input cell. Flyback Input Voltage (minimum) 200 V 200 V

Flyback Output Voltage 19 V 19 VLm p (Primary Side Flyback Inductance) 3.36E-04 H 3.36E-04 HLs (Secondary Side Flyback Inductance) 9.33E-06 H 9.33E-06 H

Turn Ratio, n = Np/Ns 6.00 6.00Switching frequency, fsw 6.75E+04 Hz 6.75E+04 Hz

Switching Period 1.48E-05 S 1.48E-05 SDuty Cycle, D (DCM but use CCM formula) 36.31% % 36.31% %

1-D 63.69% % 63.69% % Maximum Output Power 100 W 100 W

PWM system only efficiency 86% % 86% %Maximum input Power 116 W 116 W

Primary Peak Current @ Full load & Steady State 3.20E+00 A 3.20E+00 A Primary Peak Current with D=Dmax=50% @200V 4.41E+00 A 4.41E+00 A

Secondary Peak Current @200V 2.65E+01 A 2.65E+01 ARpwmsense 3.90E-01 OHM 3.90E-01 OHM

RV+I 500 OHM 500 OHMQphoto Couple Current @ 100% load 5.00E-04 A 5.00E-04 A

Voltage Drop cross RPWMRSENSE @ 100% load 1.25E+00 V 1.25E+00 V Voltage Drop cross RV+I @ 100% load 2.50E-01 V 2.50E-01 VQphoto Couple Current @ 50% load 1.75E-03 A 1.75E-03 A

Voltage Drop cross RPWMRSENSE @ 50% load 6.25E-01 V 6.25E-01 VVoltage Drop cross RV+I @ 50% load 8.75E-01 V 8.75E-01 VQphoto Couple Current @ 20% load 2.50E-03 A 2.50E-03 A

Voltage Drop cross RPWMRSENSE @ 20% load 2.50E-01 V 2.50E-01 VVoltage Drop cross RV+I @ 20% load 1.25E+00 V 1.25E+00 V

RPWMTRIFAULT1 2.60E+03 OHM 2.68E+03 OHMRPWMTRIFAULT2 + RNTC1 4.20E+04 OHM 4.20E+04 OHM

VCC=15V 15 V 15 VPWMTRIFAULT Voltage @ 20% load VCC="B12" 7.76E+00 V 6.80E+00 VPWMTRIFAULT Voltage @ 50% load VCC="B12" 9.71E+00 V 9.57E+00 V

Short Threshold ~ 14.3 V 14.3 VGreen Mode Threshold ~ 6.8 V 6.8 V





CPWMTRIFAULT 2.24E-07 F 2.24E-07 F CV+I 1.50E-10 F 1.50E-10 F

Design OK or Not TRUE TRUE

71


Increase Start-Up Resistor above 2M ohm without

Increasing Turn-On Time


Light Load Efficiency ↑, Goes up, as Rac ↑,V↓& fpwm↓

72




73




RAC functions:

• Serve as a Start-Up Resistor

• Feed-forward input Sine wave for PFC

1. Leading-edge-modulation-PFC-current-loop

slope compensation

2. Power Limit


74Light Load Efficiency ↑, Goes up, as Rac ↑,V↓& fpwm↓


Improve Efficiency @ Light Load

CM6805/CM6806:

•Reduce PWM switching frequency by pulse skipping

•Turn Off PFC @ Green-Mode Threshold, GMth

•Increase Start-Up resistor, RAC > 2M ohm

@ No Load, Pin<0.3W

75


CM6805, CM6806 and CM6903

PFC - FlyBack

AC Adapter Controller

CM6805/CM6806/CM6903/CM6201

76


PFC Start Up then PWM Start Up

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

77


Soft Start for both PFC and Flyback

PFC Soft Start with PWM Soft StartCM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

78


Fast PFC Voltage Loop

Speed up the PFC Voltage Loop

by 3X

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

79



Error Amplifier

Transconductance Amp, GM vs.

Operational Amp, OP

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

80



Transconductance Amp, GM

Operational Amp, OP

Output Impedance, Zout ?

Output Impedance, Zout ?

Input Impedance Zin?

Input Impedance Zin ?

Zin ~ High

Zin ~ High

Zout ~ High

Zout ~ Low

Transconductance Amp, GM vs.

Operational Amp, OP

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

81



2 Main Purposes of the Error Amp

1. Force V+ = V- and it means Vfb = 2.5V

2. Compensation: It needs the Rc and Cc

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

82



VFB

OP Integrator

The Miller Effect slows down the Vfb node.Also, PFC Voltage Loop is very slow.The consequence: Vfb becomes very slow.

This local feedback is bad!

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

83



For GM,there is no local feedback.There is only one outer loop and there is no inner loop.Vfb is a much faster node.

GM Integrator

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

84



GMV (mho)

0

12u/div

2.5V0V 3.0V

Iveao (uA)

12u/div69.3u mho

-208.6nA

0uA

-60uA

60uAFB

VEAOV ΔV

ΔIGM

VFB

VFB=2.51V

CM6805, CM6806 and CM6903CM6805/CM6806/CM6903/CM6201

85


Easy to meet UL1950

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

86


• Leading Edge Modulation PFC• Synchronize with Trailing Edge Modulation PWM• Smaller 400V Bulk Capacitor with 1% better efficiency and 30% ripple reduction• Simplest PFC control, Input Current Shaping Technique, ICST (Open Loop Current Mode)• It works for both CCM or DCM• Fixed Switching Frequency, fpfc = 67.5Khz for easy input EMI filter design• Automatic Slope Compensation with IAC• Rac at IAC pin serves as a Start-Up Resistor• 3X PFC Voltage Loop• PFC has a Tri-fault protections for UL1950• PFC Soft Start• PFC OVP + VCC OVP• PFC Current Limit• Universal Input• AC Brown Out• Automatic Turn Off @ Green Mode• Easy to configure into Boost Follower

PFC Features

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

87


PWM Features

• Design for FlyBack Converter• Constant Maximum Power• Current Mode with inherent slope compensation• Constant Switching Frequency, fpwm = 67.5Khz (CM6805 and

CM6903), fpwm = 135Khz (CM6806)• Exact 50% maximum duty cycle• PWM has a PWMTri-fault protections for short and Green Mode• PWMTrifault can be programmed to turn off PFC @ Green Mode• PWMTrifault can be programmed to detect the short or can be

programmed to do thermal protection• PWM has 10 mS digital soft start• CM6805/CM6806 in 10 pin SOIC packages• CM6903 in 9 pin SIP package

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

88


More Features

· Input Power, Pin<0.3 W @ No Load

· 23V BiCMOS (it can drive IGBT)

· ISTART ~ 100µA

· IOPERATING ~ 2mA without load

· Industry First CM6805/CM6806 PFC-PWM Combo in 10 pin

SOIC packages

· Industry First PFC-PWM Combo CM6903 in 9 pin SIP package

CM6805, CM6806 and CM6903

CM6805/CM6806/CM6903/CM6201

89


CM6903

Input Current Shaping Technique PFC with Leading Edge Modulation

CM6805, CM6806 and CM6903

90


CM


CM6805, CM6806 and CM6903

91


CM6903


CM6805, CM6806 and CM6903

92


How does it work?


CM6805, CM6806 and CM6903

93


10pin SOIC PFC-PWM combo: CM6805/CM6806


94


9pin SIP PFC-PWM combo: CM6903


95


Typical CM6805/CM6806 & CM6903 application circuit

Circuit configuration has been modified.

400V Rated Capacitors Can Be Used!

6

ISENSE

8VFB

4

PFCOUT

7

VEAO

9IAC

2

VCC

3

PWMOUT

1

DCILIMIT

5

GND

VOUT

2.5V

VREF OK

2.75V

2.5V

-1V

0.5V

18V

VCC_CIRCLE

PWM CLK

19.4V

VREF OK

2.5V

VCC

VFB

1.5V

0.75V

0.5V

VEAO

SS

VCC

+

-

PWMCMP

-

.-

+

R13R14

UVLO

. .

R17

R16

SR1

C21

R2

D8

R15

D10

C1

U2

R10Q3

F1

L1

D1

D2Z1

S

R

Q

Q

R

100K ohm

VCC OVP+

-

.-

+

-

.

PFC OVP+

-

.-

PFC ILIMIT+

-

.

+

-

.

PFCCMP+

-

.

RAC

VIN OK

+

-

.+

. .

S

R

Q

Q

R

D10

R5

400K ohm

R4

10mS

. .

.

C5

C4

D8D9D11

R19

C13

D6

C14R11

C15

C11 C7

C16

C8

R3

C9

D3

R11

C8

R7

R20 T2

C9

T1

C10

D7

R8

R12

PFCCLKB

PWMCLK.

.

R9

Q1

CFilter

Q2

D5

PWMOFF

+

-

.

S

R

Q

Q

R

R

RFIlter

T1

+

+ OUT

U1

SUM

..

.

.

D13

D12

D4

C17

L2

1K ohm

C19

C18

VREFOK

AC IN

FAULTB

PFCCLKB

RAMP

fpfc= 67KHz

R1A

fpwm= 67KHz

67KHz

fpwm=

R1B

fpfc=

134KHz

CM6903 CM6904

Tri-FaultDetect

gmv

ISENSEAMP

OSC

R1C

UVLO

SS

PWMCLK

1V


96


PWM SECTIONCM6805, CM6806 and CM6903

97


CM6805/CM6806/CM6903 PFC Controller:

Leading Edge Modulation

with Input Current

Shaping Technique

(ICST)


PFC Control

98


•ICST is based on the following equations:

in

ine IVR

inl II

•Equation 2 means: average boost inductor current equals to input current.•Assume that input instantaneous power is about to equal to the output instantaneous power.

doutlin IVIV

•For steady state and for the each phase angle, boost converter DC equation at continuous conduction mode is:

)1(1

dVV

in

out

(3)


PFC ControlCM6805, CM6806 and CM6903

99


•Rearrange above equations, (1), (2),(3), and (4) in term of Vout and d, boost converter duty cycle and we can get average boost diode current equation (5):

e

outd R

VdI 2)1(

•Also, the average diode current can be expressed as:

dttIT

IoffT

dsw

d )(1

0

(5)



100


•If the value of the boost inductor is large enough, we can assume

dd ItI ~)(

•It means during each cycle or we can say during the sampling, the diode current is a constant.•Therefore, equation (6) becomes:

)1(' dIdITtI

I ddsw

offdd

, Id is constant during each switching period, 1/67.5khz.



101


•Using this simple equation (8), we implement the PFC control section of the PFC-PWM controller, CM6805, CM6806, CM6903 & CM6501

sw

off

e

outd

e

outd

e

outd

T

t

R

VI

RVdI

RVddI

'

2'' )(

(8)

Input Current Shaping Technique (ICST) PFC with Leading Edge

Modulation

PFC Control

CM6805, CM6806 and CM6903

102

Jeffrey Hwang10 min to design your power supply (V) Input Current Shaping Technique (ICST) PFC with Leading Edge

Modulation

PFC Control

Review Leading Edge Modulation & Average Current Mode PFC Control

CM6805, CM6806 and CM6903

103


ModulationCM6805, CM6806 and CM6903

104



105


Usually, the pole of Isense filter ~ 1/6 of the switchingfrequency, and it is 67.5khz/6 = 1/(2×π×Rfilter×Cfilter)

If Rfilter =1K Ω, Cfilter=14.15nF.

2 purposes to add Isense filter:• Protect IC during inrush current• Using smaller inductor and still having good THD



106


Modulation

D<50% needs Slope Compensation

CM6805, CM6806 and CM6903

107


Modulation


CM6805, CM6806 and CM6903

108


Modulation


CM6805, CM6806 and CM6903

109


Modulation


CM6805, CM6806 and CM6903

110


Modulation


CM6805, CM6806 and CM6903

111


Modulation


CM6805, CM6806 and CM6903

112


Modulation


CM6805, CM6806 and CM6903

113


Modulation


CM6805, CM6806 and CM6903

114


Modulation


CM6805, CM6806 and CM6903

115


PFC Section

For CM6805/CM6806 & CM6903,Bleed Resistor Not Required

Negative Charge Pump Not Requiredfor the PFC section


Modulation

D<50% needs Slope CompensationCM6805, CM6806 and CM6903

116


TIME

IACTIME

ISENSEOUT

TIME

ISENSEOUT+IAC

IAC enhances the THD during light load and high line ftSinB 2

ftSinA 2

ftSinBA 2)(


Modulation


CM6805, CM6806 and CM6903

117


CM6800 or CM6805 Family

For CM6800 family, ΔVEAO=6V-0.625V=5.375V and For CM6805, CM6806 and CM6903, ΔVEAO=(6V-0.625V)/4=1.34V


Voltage LoopCM6805, CM6806 and CM6903

118


CM6805/CM6806 & CM6903 PWM Control:

1.5V Precision Current CMP +

10 ms Digital Soft Start


Modulation&

Trailing Edge Modulation PWM

119


PWM Section

6

ISENSE

8VFB

4

PFCOUT

7

VEAO

9IAC

2

VCC

3

PWMOUT

1

DCILIMIT

5

GND

VOUT

2.5V

VREF OK

2.75V

2.5V

-1V

0.5V

18V

VCC_CIRCLE

PWM CLK

19.4V

VREF OK

2.5V

VCC

VFB

1.5V

0.75V

0.5V

VEAO

SS

VCC

+

-

PWMCMP

-

.-

+

R13R14

UVLO

. .

R17

R16

SR1

C21

R2

D8

R15

D10

C1

U2

R10Q3

F1

L1

D1

D2Z1

S

R

Q

Q

R

100K ohm

VCC OVP+

-

.-

+

-

.

PFC OVP+

-

.-

PFC ILIMIT+

-

.

+

-

.

PFCCMP+

-

.

RAC

VIN OK

+

-

.+

. .

S

R

Q

Q

R

D10

R5

400K ohm

R4

10mS

. .

.

C5

C4

D8D9D11

R19

C13

D6

C14R11

C15

C11 C7

C16

C8

R3

C9

D3

R11

C8

R7

R20 T2

C9

T1

C10

D7

R8

R12

PFCCLKB

PWMCLK.

.

R9

Q1

CFilter

Q2

D5

PWMOFF

+

-

.

S

R

Q

Q

R

R

RFIlter

T1

+

+ OUT

U1

SUM

..

.

.

D13

D12

D4

C17

L2

1K ohm

C19

C18

VREFOK

AC IN

FAULTB

PFCCLKB

RAMP

fpfc= 67KHz

R1A

fpwm= 67KHz

67KHz

fpwm=

R1B

fpfc=

134KHz

CM6903 CM6904

Tri-FaultDetect

gmv

ISENSEAMP

OSC

R1C

UVLO

SS

PWMCLK

1V


Modulation&

Trailing Edge Modulation PWM


120


Modulation


121

Design High Density AC Adapter

8 Pin 12V Secondary Fly Back Smart Driver, CM6201

VREF1

VCC2

VL_VTH3

VL4

AGND6

DCM_DET5

SRDRV7

PGND8

VCC

VOUT

VBUS

PWM

D2

D3

D4

R3

R2

R1

D1

C3

C2

C1

R5

R4

+

-

R6

-25mVM2

DIGITALCONTROL

DRV

CM62

01

VCC

DCM_DET

VREF

AGNDVL_VTH

VL

SRDRV

PGND

+

-

UVLOBIASBG

M1

OSC


122

Design High Density AC Adapter

8 Pin 12V Secondary Fly Back Smart Driver, CM6201

• Pin to pin compatible with STSR30• Supply voltage range: 7 to 13.2V• Feed-Forward Peak Detect for wide input range• CCM or DCM Fly-back operation• Operating Frequency: up to 750 KHz• Automatic turn off for duty cycle less than 12.5%• Smart turn off (240nS)• Output driver: 15 Ohms sourcing and 6 Ohms

sinking capability


123

24-hour Engineering Supports

• Champion Design Center– www.champion-micro.com

• Design Excel Spread Sheets– PWM design for Flyback Converter Section– CM6805, CM6806, CM6903 Design Tool



124

PWM design for Flyback Converter Section


CM6805/CM6806 PWM SECTION for FlyBack Design User Inputs All Resistors, inductor and VCC Units User Inputs the Optical Couple Current and VCC

If the cell is filled with yellow color, it is a user input cell. Flyback Input Voltage (minimum) 200 V 200

Flyback Output Voltage 19 V 19Lm p (Primary Side Flyback Inductance) 3.36E-04 H 3.36E-04Ls (Secondary Side Flyback Inductance) 9.33E-06 H 9.33E-06

Turn Ratio, n = Np/Ns 6.00 6.00Switching frequency, fsw 6.75E+04 Hz 6.75E+04

Switching Period 1.48E-05 S 1.48E-05Duty Cycle, D (DCM but use CCM formula) 36.31% % 36.31%

1-D 63.69% % 63.69%Maximum Output Power 100 W 100

PWM system only efficiency 86% % 86%Maximum input Power 116 W 116

Primary Peak Current @ Full load & Steady State 3.20E+00 A 3.20E+00Primary Peak Current with D=Dmax=50% @200V 4.41E+00 A 4.41E+00

Secondary Peak Current @200V 2.65E+01 A 2.65E+01Rpwmsense 3.90E-01 OHM 3.90E-01

RV+I 500 OHM 500Qphoto Couple Current @ 100% load 5.00E-04 A 5.00E-04

Voltage Drop cross RPWMRSENSE @ 100% load 1.25E+00 V 1.25E+00Voltage Drop cross RV+I @ 100% load 2.50E-01 V 2.50E-01

Qphoto Couple Current @ 50% load 1.75E-03 A 1.75E-03Voltage Drop cross RPWMRSENSE @ 50% load 6.25E-01 V 6.25E-01

Voltage Drop cross RV+I @ 50% load 8.75E-01 V 8.75E-01Qphoto Couple Current @ 20% load 2.50E-03 A 2.50E-03

Voltage Drop cross RPWMRSENSE @ 20% load 2.50E-01 V 2.50E-01Voltage Drop cross RV+I @ 20% load 1.25E+00 V 1.25E+00

RPWMTRIFAULT1 2.60E+03 OHM 2.68E+03RPWMTRIFAULT2 + RNTC1 4.20E+04 OHM 4.20E+04

VCC=15V 15 V 15PWMTRIFAULT Voltage @ 20% load VCC="B12" 7.76E+00 V 6.80E+00PWMTRIFAULT Voltage @ 50% load VCC="B12" 9.71E+00 V 9.57E+00

Short Threshold ~ 14.3 V 14.3Green Mode Threshold ~ 6.8 V 6.8





CPWMTRIFAULT 2.24E-07 F 2.24E-07CV+I 1.50E-10 F 1.50E-10

Design OK or Not TRUE TRUE


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CM6805 CM6806 CM6903 Design Tool


CM6803 CM6804 CM6805 CM6806 CM6903 CM6904 Design Tool / Jeffrey H. Hwang Yellow cells are for user inputGreen-Mode Design USER INPUT INDUCTOR and CAPACITOR CALCULATED INDUCTOR and CAPACITOR

Output Pow er (Watt) 300 300PFC Output Voltage (V) 380 380

High LineEff iciency at High Line (%) 96 96High Line; Maximum Line Input Voltage (Vrms) (V) 260 260Peak Input Voltage at High Line(V) 367.6955262 367.6955262Input Line Current at High Line (Irms) (A) 1.201923077 1.201923077Peak High Line Current (A) 1.699775916 1.699775916Peak High Line Sw itching Current (A) 1.87616188 2.124719895Ripple Current at Peak High Line (%) 9.40142561 50Ripple Current at Peak High Line (A) 1.76E-01 0.424943979 Input Pow er at High Line (Watt) 312.5 312.5System Sw itching Frequency (Hz); Fixed fsw = 67.5 Khz 6.75E+04 6.75E+04Tperiod, Sw itching Cycle (Sec); Fixed fsw = 67.5 Khz 1.48E-05 1.48E-05Sw itch-On-Time at Peak input voltage (Sec) Assumed in CCM 4.80E-07 4.80E-07Sw itch-Off-Time at peak input voltage (Sec) Assumed in CCM 1.43E-05 1.43E-05Sw itching Duty Cycle at peak input voltage (%) Assumed in CCM 3.24E+00 3.24E+00

Low LineEff iciency at Low Line (%) 94 94Low Line; Minimum Line Input Voltage (Vrms) (V) 80 80Peak Input Voltage at Low Line (V) 113.137085 113.137085 Input Line Current at Low Line (Irms) (A) 3.989361702 3.989361702Peak Low Line Current (A) 5.641809424 5.641809424 Peak Low Line Sw itching Current (A) 6.82E+00 7.06E+00Ripple Current at Peak High Line (%) 17.26204392 20.08431848Ripple Current at Peak High Line (A) 1.18E+00 1.42E+00 Input Pow er at Low Line (Watt) 319.1489362 319.1489362Sw itch-On-Time at Peak input voltage (Sec) Assumed in CCM 1.04E-05 1.04E-05Sw itch-Off-Time at peak input voltage (Sec) Assumed in CCM 4.41E-06 4.41E-06Sw itching Duty Cycle at peak input voltage (%) Assumed in CCM 7.02E+01 7.02E+01

EXTERNAL POWER COMPONENTS RSENSE (Ohm) 0.08862405 0.08862405RAC (Ohm) 1.430E+06 1.430E+06 OPTION1: RACvcc (Ohm): the resistor betw een VCC and IAC 5.000E+05 5.000E+05Input Inductor for PFC Boost (H) 5.000E-04 4.151E-04Output Capacitor for PFC Boost (F) 2.50E-04 9.72E-05PFC Boost Output Before Droping for the Hold-Up Time Calculation

(V) 380 380PFC Boost Output After Droping for the Hold-Up Time Calculation

(V) 114 114Hold-Up Time (Sec) 0.051466567 0.02

COMPENSATION AND FEEDBACK for PFC Voltage Loop VEAO is a GMv, a Slew Rate Enhancement Transconductance

Amplif ier, a Voltage Loop Error Amplif ier

GMv, Transconductance at the w orse condition (mho) 9.00E-05 9.00E-05dVEAO for the maximum Pow er (V) 1.980E+00 1.980E+00Rvfb1 + Rvfb2 (Ohm) 3.00E+06 3.00E+06 Rvfb1 (Ohm) for VFB=2.5V 2.98E+06 2.98E+06Rvfb2 (Ohm) for VFB=2.5V 1.97E+04 1.97E+04R1c, Compensation Resistor for f tv =20Hz (Ohm) 1.25E+05 4.86E+04


126

Summary High Density AC Adapter Design

• without additional cost– PFC: Efficiency~95.5% without additional cost

• 2 Level Boost Follower (200V and 380V)• Use LETE, CM6805, CM6806 and CM6903 family

– FlyBack: Efficiency~87.5% (without SR)– FlyBack: Efficiency~90% (with SR,

CM6201)– Total Efficiency ~ from 83.56% to 86%


Design a Champion AC Adapter

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