FA3647 Fuji Electric holdings CO.,Ltd, FA3647 Datasheet
FA3647
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FA3647 Summary of contents
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... FA3641P(N), FA3647P(N) FA3641P(N), FA3647P(N) Description The FA3641P(N) and FA3647P(N) are the PWM type switching power supply control ICs that can directly drive power MOSFET. These ICs use a CMOS device with high dielectric strength (30V) to implement low power consumption. They feature a number of functions that are equivalent to those of the FA531X series consisting of bipolar devices ...
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... Sink current +1.0 Source current –0.5 –0.3 to 5.0 –10 –0.3 to 5.0 2 =25˚C DIP 800 * * 2 SOP 400 –30 to +85 125 –40 to +150 Maximum power dissipation curve 400mW (SOP) 800mW (DIP) 0 –30 25 Ambient temperature Ta [˚C] FA3641P(N), FA3647P(N) Unit ˚C ˚C ˚C 85 125 59 ...
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... FA3641P(N), FA3647P(N) Recommended operating condition Item Supply voltage REF pin bypass capacitor Soft-start capacitor Oscillation frequency (FB >1.2V) Min.oscillation frequency at light load mode (FB <1.2V) Electrical characteristics (Vcc=18V, R Reference voltage section Item Reference voltage Voltage variation 1 (Line regulation) Voltage variation 2 (Load regulation)) Voltage variation 3 (Temperature stability) ...
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... CC tr OUT=1000pF tf OUT=1000pF Symbol Test condition I V =14V CC STB CCON I No load =17V, Cs=0V CCOF =10V CCL CC FA3641P(N), FA3647P(N) Min. Typ. Max. Unit –4.0 –6.5 –9.0 A 0.82 0.95 V 0.50 0.68 V Min. Typ. Max. Unit 8.0 8.5 9.0 V 7.4 7.9 8.4 V 0.6 V Min ...
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... FA3641P(N), FA3647P(N) Characteristic curves (Ta=25˚C) Oscillation frequency (fosc) vs. timing resistor resistance ( 1000 100 V = 18V 1. Oscillation frequency (fosc) vs. junction temperature (Tj) 105 Rt = 47k FB = 2.5V 104 103 102 101 100 – Supply current (Icc) vs. supply voltage (Vcc) Operating mode 2 1.95 1.9 1.85 1.8 ...
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... Supply current (Icc) vs. supply voltage (Vcc) OFF mode 3000 2500 2000 1500 1000 500 UVLO ON-to-OFF thrreshold voltage (Vcc off) vs. junction temperature (Tj) 9.2 9.1 9 8.9 8.8 100 150 –50 FA3641P(N), FA3647P( Vcc [ Vcc [V] 0 100 150 ...
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... FA3641P(N), FA3647P(N) CS terminal current (Ics) vs. CS terminal voltage (Vcs Open –5 – Vcs [V] CS terminal charge current (Ichg) vs. junction temperature (Tj) –5 –6 –7 –8 –9 Vcc =18V –10 – (+) terminal current (I ) vs. IS (+) IS (+) terminal voltage ( (+) FA3641 0 –0.1 –0.2 –0.3 –0.4 0 0.5 1 ...
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... During normal operation, the output pulse width is determined within the maximum duty cycle (70%) set by DT voltage under the condition set by FB pin voltage stabilize the output voltage controls soft , to Fig. 5 PWM comparator timing chart FA3641P(N), FA3647P(N) Fig. 1 Oscillator Fig. 2 Oscillator output Fig. 3 Oscillation frequency Fig. 4 PWM comparator 65 ...
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... FA3641P(N), FA3647P( pin circuit As shown in Figure 6, capacitor Cs is connected to the CS pin. The CS pin voltage varies depending on the charging voltage of this capacitor Cs. When the power is turned on, the constant current source (6.5 A) begins to charge capacitor. Accordingly, the CS pin voltage rises as shown in Figure 7. The CS pin ...
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... CS pin voltage exceeds 0.82V (typ). This turns on the 5V REF circuit and results in automatic soft start. The power supply then restarts operation. Fig. 12 External output ON/OFF control circuit FA3641P(N), FA3647P(N) Fig. 10 Overload shutdown circuit Fig. 11 Overload shutdown timing chart Fig. 13 Output ON/OFF control circuit timing chart ...
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... Rs and fed to the IS pin of the IC. If the voltage exceeds the reference voltage +0.235V (FA3641) or –0.168V (FA3647) of comparator C4, comparator C4 works to set flip- flop output Q to high. The output is immediately turned off to shut off the current. Flip-flop output Q is reset on the next cycle to turn on the output again ...
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... Therefore, check the operation using a practical circuit to make a final decision. Calculation example To set the fixed frequency f = 100kHz and minimum frequency O in light-load mode 20kHz, the following can be obtained from expressions (5 185 Decrease Rr to permit the frequency to vary in a wider range. ............................ (5) 2500 ....... (6) RtRr + 6 FA3641P(N), FA3647P(N) Fig. 18 Oscillator circuit 69 ...
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... FA3641P(N), FA3647P(N) 2. Deciding the startup circuit These ICs, which use CMOS process, consume less current, and therefore can use larger startup resistance than the conventional bipolar type of IC. To decide the startup resistance, the following conditions must be satisfied: (a) The IC is started when the power is turned on. ...
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... If the overload shutdown or overvoltage shutdown functions raise the CS pin voltage to around 5V, zener diode Zn becomes conductive to charge capacitor CL. The OFF latch delay can be thus prolonged by capacitance CL. FA3641P(N), FA3647P(N) When the capacitor value is adequate Fig. 21 Vcc voltage at startup with an adequate capacitor When the capacitor value is inadequate Fig ...
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... FA3641P(N), FA3647P(N) 6. Overvoltage protection using the VCC pin These ICs contain an overvoltage protection function detecting the Vcc voltage using internal ZD (See item 6 in “Description of each circuit”). If Vcc voltage exceed about 32V, the current of 13mA flows through the internal ZD and the overvoltage protection function operates ...
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... Polarities for overcurrent detecting and their characteristics The FA3641 uses positive polarity detection for overcurrent limiting (number 3 pin of IS pin) and the FA3647 uses negative polarity detection. The characteristics of positive and negative polarity detection are summarized below. Select one in accordance with the circuit used. (See item 5 in “Description of each circuit.” ...
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... FA3641P(N), FA3647P(N) 13. Correcting overload detection current (FA3641 only) If the power supply output is overloaded, the IC overcurrent limiting function restricts the output power and the overload shutdown function stops the IC. The output current when an overload occurs varies depending on the input voltage; the higher the input voltage, the more the overload detection current may increase ...
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... When the total gate charge of the power MOSFET is Qg, the switching frequency the supply voltage is Vcc, and SW gate resistance is Rg, the loss caused at the IC output circuit is given by Ron Pdr = Vcc Qg fsw 2 Rg Ron ) Roff ....... (16) Rg Roff FA3641P(N), FA3647P(N) Fig. 35 Output stage 75 ...
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... FA3641P(N), FA3647P(N) When gate resistance differs between ON and OFF as shown in Figure 36, the loss is given by Ron Pdr = Vcc Qg fsw 2 Rg1 Rg2 Ron Example: When Vcc = 18V 80nC, fsw = 100kHz, and the typical IC loss is given by Pdr = 18V 80nC 100kHz 2 10 =72.8mW (3) Total loss ...
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... Application circuit FA3641 FA3647 Parts tolerances characteristics are not defined in the circuit design sample shown above. When designing an actual circuit for a product, you must determine parts tolerances and characteristics for safe and economical operation. FA3641P(N), FA3647P(N) 77 ...
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... FA3641P(N), FA3647P(N) Electrical characteristics of application circuit Input power vs. input voltage 0.6 0.5 0.4 0.3 0.2 0.1 0 150 200 0 50 100 Input voltage [Vac] Oscillation frequency vs. output power 90 80 100V 230V Output power [W] 78 Input power vs. output power Condition:No-load 250 300 50 60 ...