Features: Patents Pending
u Pin to pin compatible with CM6800, CM6800A, ML4800, and FAN4800
u 23V Bi-CMOS process
u Designed for EPA/85+ efficiency
u Selectable Boost output from 380V to 342V during light load
u Digitized Exactly 50% Maximum PWM Duty Cycle
u 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
u Rail to rail CMOS Drivers with on, 60 ohm and off, 30 ohm for both PFC and PWM with two 17V zeners
u Fast Start-UP Circuit without extra bleed resistor to aid
VCC reaches 13V sooner
u Low start-up current (55uA typ.)
u Low operating current (2.5mA typ.)
u 16.5V VCC shunt regulator
u Leading Edge Blanking for both PFC and PWM
u fRTCT = 4*fpfc =4*fpwm for CM6802SAH
u fRTCT = 4*fpfc =2*fpwm for CM6802SBH
u Dynamic Soft PFC to ease the stress of the Power
Device and Ease the EMI filter design
u Clean Digital PFC Brown Out and PWM Brown Out
u Turbo Speed PFC may reduce 420 Bulk Capacitor size
u 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
u Better Power Factor and Better THD
u Average current, continuous or discontinuous boost leading edge PFC
u PWM configurable for current mode or feed-forward voltage mode operation
u Current fed Gain Modulator for improved noise immunity
u Gain Modulator is a constant maximum power limiter
u Precision Current Limit, over-voltage protection, UVLO, soft start, and Reference OK
ApplicationEPA/85+ related Power Supply
u Desktop PC Power Supply
u Internet Server Power Supply
u LCD Power Supply
u PDP Power Supply
u IPC Power Supply
u UPS
u Battery Charger
u DC Motor Power Supply
u Monitor Power Supply
u Telecom System Power Supply
u Distributed Power
Specificationsoing 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=67Khz, fpwm=67Khz, frtct=268Khz for CM6802SAH and fpfc=67Khz, fpwm=134Khz, frtct=268Khz 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 CM6800s 20uA to
CM6802SAH/SBHs 10uA.Soft Start capacitor can be reduced to 1/2 from your original
CM6800 capacitor.
DescriptionAround 2% efficiency gain when the output load CM6802SAH/SBH 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 Data Sheet
