CM6802SAH/SBH
http://www.championmicro.com.tw
(Turbo-Speed PFC+Green PWM)
EPA/85+ ZVS-Like PFC+PWM COMBO CONTROLLER
Design for High Efficient Power Supply at both Full Load and Light Load
GENERAL DESCRIPTION
CM6802SAH/SBH is a turbo-speed PFC and a Green PWM
controller. It is designed to further increase power supply
efficiency while using the relatively lower 380V Bulk
Capacitor value.
Switching to CM6802SAH/SBH from your existing CM6800
family boards can gain the following advanced
performances:
Around 2% efficiency gain when the output load is
below 40% of the full load
2.) Hold Up time can be increased ~ 30% from the
existing 6800 power supply
3.) Turbo Speed PFC may reduce 420 Bulk Capacitor
size
4.) 420V bulk capacitor value may be reduced and PFC
Boost Capacitor ripple current can be reduced
5.) No Load Consumption can be reduced 290mW at
270VAC
6.) Better Power Factor and Better THD
7.) Clean Digital PFC Brown Out
8.) PWM transformer size can be smaller
9.) Superior Surge Noise Immunity
10.) To design 12V, 5V, and 3.3V output filters can be
easy
11.) The stress over the entire external power device is
reduced and EMI noise maybe reduced; PFC inductor
core might be reduced
12.) Monotonic Output design is easy
13.) And more… Of course, the cost can be reduced
CM6802SAH/SBH is pin to pin compatible with CM6800
family.
Beside all the goodies in the CM6800, it is designed to meet
the EPA/85+ regulation. With the proper design, its efficiency
of power supply can easily approach 85%.
To start evaluating CM6802SAH/SBH 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
ohm to 8 Mega ohm. Start with 6 Mega ohm for RAC
first.
2.) Change RTCT pin (pin 7) from the existing value to
RT=5.88K ohm and CT=1000pF to have
fpfc=68Khz,
fpwm=68Khz,
frtct=272Khz
for
CM6802SAH and
fpfc=68Khz, fpwm=136Khz,
frtct=272Khz for CM6802SBH
3.) Adjust all high voltage resistor around 5 mega ohm or
higher.
4.) VRMS pin(pin 4) needs to be 1.14V at VIN=80VAC
for universal input application from line input from
80VAC to 270VAC. Both poles for the Vrms of the
CM6802SAH/SBH 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 when the load triggers the light load
comparator.
6.) Soft Start pin (pin 5), the soft start current has been
reduced from CM6800’s 20uA to CM6802SAH/SBH’s
10uA.Soft Start capacitor can be reduced to 1/2 from
your original CM6800 capacitor.
1.)
FEATURES
Patents Pending
Pin to pin compatible
ML4800, and FAN4800
23V Bi-CMOS process
Designed for EPA/85+ efficiency
Selectable Boost output from 380V to 342V during light
load
Digitized Exactly 50% Maximum PWM Duty Cycle
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 CM6802SAH
fRTCT = 4*fpfc =2*fpwm for CM6802SBH
Dynamic Soft PFC to ease the stress of the Power
Device and Ease the EMI filter design
Clean Digital PFC Brown Out and PWM Brown Out
Turbo Speed PFC may reduce 420 Bulk Capacitor size
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
Better Power Factor and Better THD
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
Precision Current Limit, over-voltage protection, UVLO,
soft start, and Reference OK
with
CM6800,
CM6800A,
2009/11/02
Rev. 1.5
Champion Microelectronic Corporation
1
CHAMP [ CHAMPION MICROELECTRONIC CORP. ]
