CM6802A/B/AH/BH
(Dynamic Soft PFC/Green PWM)
http://www.championmicro.com.tw
EPA/80++ ZVS-Like PFC/PWM COMBO CONTROLLER
Design for High Efficient Power Supply at both Full Load and Light Load
GENERAL DESCRIPTION
Switching to CM6802A/B/AH/BH from your existing
CM6800 family boards can gain the following advanced
performances:
1.)
2.)
3.)
Around 2% efficiency gain when the output load is
below 40% of the full load.
Hold Up time can be increased ~ 30% from the
existing 6800 power supply.
420V bulk capacitor value may be reduced PFC
boost ripple current can be reduced; therefore, the
boost inductor core size maybe reduced.
No Load Consumption can be reduced 290mW at
270VAC.
PWM transformer size can be smaller.
To design 12V, 5V and 3.3V output filters can be
easy.
The stress over the entire external power device is
reduced and EMI noise maybe reduced.
Monotonic Output design is easy and more…Of
cause, the cost will be reduced.
FEATURES
Patents Pending
Pin to pin compatible
ML4800 and FAN4800.
23V Bi-CMOS process.
Designed for EPA/80++ efficiency.
CM6802A/B : Selectable Boost output from 380V to
300V during light load.
CM6802AH/BH: Selectable Boost output from 380V to
342V during light load.
All high voltage resistors can be greater than 4.7 Mega
ohm (4.7 Mega to 8 Mega ohm) to improve the no load
consumption.
Rail to rail CMOS Drivers with on, 60 ohm and off, 30
ohm for both PFC and PWM with two 17V zeners.
Fast Start-UP Circuit without extra bleed resistor to aid
VCC reaches 13V sooner.
Low start-up current (55uA typ.)
Low operating current (2.5mA typ.)
16.5V VCC shunt regulator
Leading Edge Blanking for both PFC and PWM.
fRTCT = 4*fpfc =4*fpwm for CM6802A//AH
fRTCT = 4*fpfc =2*fpwm for CM6802B/BH
Dynamic Soft PFC to ease the stress of the Power
Device and Ease the EMI filter design.
PFC Brown Out and PWM Brown Out
Internally synchronized leading edge PFC and trailing
edge PWM in one IC to Reduces ripple current in the
420V storage capacitor between the PFC and PWM
sections.
Low total harmonic distortion, THD and Power Factor
approaches 1.0.
Average current, continuous or discontinuous boost
leading edge PFC.
PWM configurable for current mode or feed-forward
voltage mode operation.
Current fed Gain Modulator for improved noise immunity.
Gain Modulator is a constant maximum power limiter.
Brown-out control, over-voltage protection, UVLO, and
soft start, and Reference OK.
PWM Short Circuit Protection
Power Fold Back Protection
Green Mode PWM for less no load consumption.
with
CM6800,CM6800A,
4.)
5.)
6.)
7.)
8.)
CM6802A/B/AH/BH is pin to pin compatible with CM6800
family.
Beside all the goodies in the CM6800, it is designed to meet
the EPA/80+ regulation. With the proper design, its
efficiency of power supply can easily approach 85%.
To start evaluating CM6802A/B/AH/BH from the exiting
CM6800,CM6800A or ML4800 board, 6 things need to be
taken care before doing the fine tune:
1.) Change RAC resistor (on pin 2, IAC) from the old
value to a higher resistor value between 4.7 Mega
ohms to 8 Mega ohms.
2.) Change RTCT pin (pin 7) from the existing value to
RT=7.75K ohm and CT=1000pF to have
fpfc=55Khz, fpwm=55Khz, frtct=220Khz.
3.) Adjust all high voltage resistor around 5 mega ohm
or higher.
4.) VRMS pin (pin 4) needs to be 1.125V at
VIN=85VAC for universal input application from line
input from 85VAC to 270VAC. Both poles for the
Vrms of the CM6802A/B/AH/BH needs to
substantially slow than CM6800 about 5 to 10 times.
5.) At full load, the average Veao needs to around 4.5V
and the ripple on the Veao needs to be less than
250mV.
6.) Soft Start pin (pin 5), the soft start current has been
reduced
from
CM6800’s
20uA
to
CM6802A/B/AH/BH’s 10uA.Soft Start capacitor can
be reduced to 1/2 from your original CM6800
capacitor.
2009/11/02
Rev. 1.4
Champion Microelectronic Corporation
1
CHAMP [ CHAMPION MICROELECTRONIC CORP. ]
