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SERVICE MANUAL
38
1.9 Switch-mode Power Supply STR- W68XX
(1) General Description
The STR-W6800 Series are thick-film ICs for Quasi-Resonant flyback SMPS with MOSFET and
control built-in, featuring fewer external components, simplified circuit design, small-size and
standard power supply.
“STR-W6800 Series ICs” offers three operation modes: Quasi-Resonant, Multi-Bottom Skip and
Time Fix Control, thus guaranteeing high efficiency in all loading areas by means of the automatic
change-over of the operation modes.
QR---- Quasi-Resonant operation at the time of heavy load
MBS---- Multi-Bottom Skip operation at the time of medium load for preventing oscillating frequency
rising up and fixing operating frequency
TFC---- Time Fix Control at the time of light load such as stand-by load
By adopting chip-on-chip construction, even small package can deal with big power.
(2) Features
Seven-pin small SIP style package FM207 (generally called TO220), affording dielectric
isolation
Guarantees space of 1.8mm between high voltage pin and other pins, thus high voltage
MOSFET built-in allowed
Offers low startup current by employing BCD-Process
Automatic change-over of QR and MBS operations
With MOSFET turn-on at the bottom of VDS, "STR-W 6800 Series ICs" offers high efficiency
and low noise at the wide areas from the heavy load to stand-by load and fixed operating
frequency, and enables SMPS to become smaller.
TFC operation delivers low-power standby mode for fixing turn-on time, enabling external
components to adjust turn-on time.
Avalanche breakdown energy-guaranteed and high damage-resistance power MOSFET
By guaranteeing avalanche breakdown energy of built-in power MOSFET, "STR-W 6800
Series ICs" simplifies design of absorption circuit of surge voltage without VDSS residual
considered during design.
MOSFET fixed voltage drive circuit built in
Various protection functions
Pulse-by-pulse over-current protection
Over-voltage protection
→
lockout
Over-load protection
→
lockout
Thermal protection
→
lockout (not for STR-W6854/6)
Содержание 34T18
Страница 29: ...SERVICE MANUAL 27 4 Block Diagram Fig 11 5 Refer to Table 13 about Functions and Data of the IC s Pins ...
Страница 42: ...SERVICE MANUAL 40 2 WAVEFORMS OF KEY POINTS Waveform during C802 Startup Waveform during B Voltage Startup ...
Страница 43: ...SERVICE MANUAL 41 ...
Страница 44: ...SERVICE MANUAL 42 ...
Страница 45: ...SERVICE MANUAL 43 ...
Страница 46: ...SERVICE MANUAL 44 ...
Страница 47: ...SERVICE MANUAL 45 Waveform during V404 s Base T 64us ...
Страница 48: ...SERVICE MANUAL 46 Waveform during V404 s C Electrode ...
Страница 49: ...SERVICE MANUAL 47 ...
Страница 59: ...Circuit Diagram 2 ...
Страница 60: ...MAIN PCB ...
Страница 61: ...CRT RGB PCB ...