FAN4800I Fairchild Semiconductor, FAN4800I Datasheet
FAN4800I
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FAN4800I Summary of contents
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... Telecom System Power Supply Distributed Power Ordering Information Part Number Temperature Range FAN4800IN FAN4800IN_G © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 Description The FAN4800 is a controller for power-factor-corrected, switched-mode power supplies. Power Factor Correction (PFC) allows the use of smaller, lower-cost bulk capaci- ...
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... I SENSE 3 RAMP1 7 RAMP2 350 8 0. 20μA SS 350 5 V REF DC I LIMIT 9 © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0 POWER FACTOR CORRECTOR EAO V OVP 2.78V 17.9V Low Power TRI-FAULT Detector 0.5V PFC CMP 3.5k OSCILLATOR DUTY CYCLE LIMIT PWM CMP SS CMP 1 ...
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... RAMP1 (RtCt) 8 RAMP2 (PWM RAMP LIMIT 10 GND 11 PWM OUT 12 PFC OUT REF EAO © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0 EAO EAO SENSE REF RMS ...
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... Peak PWM OUT Current, Source or Sink PWM_OUT PFC OUT, PWM OUT Energy per Cycle T Junction Temperature J T Storage Temperature Range STG T Operating Temperature Range A T Lead Temperature (Soldering,10 Seconds) L θ Thermal Resistance JA © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 Parameter 4 Min. Max. Unit 5.5 V -3.0 0.7 V GND-0.3 V +0.3 ...
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... LOW-POWER DETECT COMPARATOR V (lp) Threshold Voltage th VCC OVP COMPARATOR V Threshold Voltage CC_OVP HY(V ) Hysteresis CC_OVP TRI-FAULT DETECT t Time to Fault Detect HIGH d(F) F(L) Fault Detect LOW © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 = 15V 52.3KΩ Condition ( 25° 25° 3V ...
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... Line Regulation ref1 ΔV Load Regulation ref2 ΔV Temperature Stability ref4 (1) V Total Variation ref2 ΔV Long Term Stability ref5 © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 (Continued) = 15V 52.3kΩ Condition – Gain Modulator I = 100μ RMS 25°C ...
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... V Under-Voltage Lockout Hysteresis th(hys) Notes: 1. This parameter, although guaranteed by design, is not 100% production tested. 2. Includes all bias currents to other circuits connected to the V 3. Gain = K × 5.375V SENSE © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 (Continued) = 15V 52.3kΩ Condition V > ...
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... V (V) FB Figure 3. Voltage Error Amplifier (gmv) Transconductance 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0.0 0.5 1.0 1.5 2.0 2.5 V (V) RMS Figure 5. Gain Modulator Transfer Characteristic (K) − GAINMOD OFFSET K × − 0.625) AC © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 100 -10 2.6 2.7 2.8 2.9 3.0 -0.8 Figure 4. Current Error Amplifier (gmi) 2.2 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 3.0 3.5 4.0 4.5 5.0 0.0 − ...
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... Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 One of these conditions is that the output voltage of the boost converter must be set higher than the peak value of the line voltage ...
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... The negative voltage on I SENSE currents flowing in the PFC circuit and is typically derived from a current sense resistor in series with the negative terminal of the input bridge rectifier. © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 . The The inverting input of the current error amplifier is a vir- EAO tual ground ...
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... Figure 4. This raises the gain-bandwidth product of the voltage loop, resulting in a much more rapid voltage loop response to such perturbations than would occur with conventional linear gain characteristics. © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0 POWER FACTOR CORRECTOR ...
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... SENSE 2) To reduce L, the boost inductor: The I can reduce the boost inductor value since the I filter behaves like an integrator before the I which is the input of the current error amplifier, I © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 The I SENSE I filter is between 100Ω and 50Ω because I ...
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... PWM power cycle. When the DC I LIMIT © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 cycle current, it also softly discharges the voltage of the soft-start capacitor. It limits the PWM duty cycle mode and the power dissipation is reduced during the dead- short condition ...
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... In most applications, an electrolytic capacitor of between 47μF and 220μF is also required across the part both for filtering and as a part of the startup boot- strap circuitry. © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 2.8 Leading/Trailing Modulation Conventional PWM techniques employ trailing-edge modulation, in which the switch turns on right after the trailing edge of the system clock ...
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... VIN DC SW1 REF U3 VEAO EA RAMP OSC CLK U4 SW2 VIN DC SW1 U3 VEAO EA REF RAMP OSC CLK U4 © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0 DFF CMP CLK Figure 10. Typical Trailing-Edge Control Scheme DFF CMP ...
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... Typical Application Circuit © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 Figure 12. Current-Mode Application 16 www.fairchildsemi.com ...
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... Typical Application Circuit © 2005 Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 (Continued) Figure 13. Voltage-Mode Application 17 www.fairchildsemi.com ...
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... Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specif- ically the warranty therein, which covers Fairchild products. Always visit Fairchild Semiconductor’ ...
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... Fairchild Semiconductor Corporation FAN4800 Rev. 1.0.6 19 www.fairchildsemi.com ...