FAN4800C − PFC + PWM Controller Combination

Not recommended for new design as of 10-Feb-2011

The highly integrated FAN4800A/C and FAN4801/02/02L are specially designed for power supplies that consist of boost PFC and PWM. They require very few external components to achieve versatile protections / compensation. They are available in 16-pin DIP and SOP packages.

The PWM can be used in either current or voltage mode. In voltage mode, feed-forward from the PFC output bus can reduce the secondary output ripple.

Compared with older productions, ML4800 and FAN4800, FAN4800A/C and FAN4801/02/02L have lower operation current that save power consumption in external devices. FAN4800A/C and FAN4801/02/2L have accurate 49.9% maximum duty of PWM that makes the hold-up time longer. Brownout protection and PFC soft-start functions are not in ML4800 and FAN4800.

To evaluate FAN4800A/C, FAN4801/02/02L for replacing existing FAN4800 and ML4800 boards, five things must be done before the fine-tuning procedure:

1. Change R_AC resister from the old value to a higher resister: between 6MΩto 8MΩ.

2. Change RT/CT pin from the existing values to R_T=6.8KΩand C_T=1000pF to have f_PFC=64KHz, f_PWM=64KHz.

3. VRMS pin needs to be 1.224V at V_IN=85 V_AC for universal input application from line input from 85V_AC to 270 V_AC. Both poles for the V_rms of FAN4801/02/02L don’t need to substantially slower than FAN4800; about 5 to 10 times.

4. At full load, the average V_EA needs to ~4.5V and the ripple on the V_EA needs to be less than 400mV.

5. Soft-Start pin, the soft-start current has been reduced to half from the FAN4800 capacitor.

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Product Status/Packaging

Index	Product	Product & Eco Status	Replacement Part Number	Packaging & Packing Info	**Package Marking Convention	Qualification Support	Compliance Certificates
1	FAN4800CNY	Not recommended for new design as of 10-Feb-2011 Green as of Jan 2009	FAN4800CSNY	MDIP 16L Details MDIP 16L Drawing  RAIL	Line 1:$Y (Fairchild logo) &Z (Plant Code) &4 (4-Digit Date Code) &K Line 2:FAN4800C Line 3:NYJ	FIT :  1   ESD (HBM) :  4500  V Moisture Sensitivity Level (MSL) :  NA   Show more... Max Reflow Temp :  999	RoHS IPC1752 RoHS/REACH/JIG RoHS/REACH/JIG
1	FAN4800CMY	Not recommended for new design as of 10-Feb-2011 Green as of Jan 2009	FAN4800CSMY	SO 16L NB Details SO 16L NB Drawing  TAPE REEL	Line 1:$Y (Fairchild logo) &Z (Plant Code) &2 (2-Digit Date Code) &K Line 2:FAN4800C Line 3:MYJ	FIT :  1   ESD (HBM) :  4500  V Moisture Sensitivity Level (MSL) :  3   Show more... Max Reflow Temp :  260	RoHS IPC1752 RoHS/REACH/JIG RoHS/REACH/JIG

Features

• ￭ Pin-to-Pin Compatible with ML4800 and FAN4800 and CM6800 and CM6800A
  ￭ PWM Configurable for Current-mode or Feed-forward Voltage-Mode Operation
  ￭ Internally Synchronized Leading-Edge PFC and Trailing-Edge PWM in one IC
  ￭ Low Operating Current
  ￭ Innovative Switching-Charge Multiplier Divider
  ￭ Average-Current-Mode for Input-Current Shaping
  ￭ PFC Over-Voltage and Under-Voltage Protections
  ￭ PFC Feedback Open-Loop Protection
  ￭ Cycle-by-Cycle Current Limiting for PWM
  ￭ Power-On Sequence Control and Soft-Start
  ￭ Brownout Protection
  ￭ Interleaved PFC/PWM Switching
  ￭ FAN4801/02/02L Improve Efficiency at Light Load
  ￭ f_RTCT=4
• f_PFC=4
• f_PWM for FAN4800A and FAN4801
  ￭ f_RTCT=4
• f_PFC=2
• f_PWM for FAN4800C and FAN4802/02L
  

Application Notes