FA5304 Fuji Electric holdings CO.,Ltd, FA5304 Datasheet
FA5304
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FA5304 Summary of contents
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... FA5304AP(S)/FA5305AP(S) Description The FA5304AP(S) and FA5305AP(S) are bipolar ICs for switching power supply control and can directly drive a power MOSFET. These ICs contain many functions in a small 8-pin package. With these ICs, a high-performance power supply can be created compactly because not many external components are needed ...
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... FA5304AP(S)/FA5305AP(S) Block diagram FA5304AP(S) FA5305AP(S) 2 Pin Pin Description No. symbol IN (–) 1 Inverting input to error amplifier FB 2 Error amplifier output IS (+) 3 Overcurrent (+) detection GND 4 Ground OUT 5 Output VCC 6 Power supply CT 7 Oscillator timing capacitor CS 8 Soft-start and ON/OFF control Pin Pin Description No ...
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... Input bias current Open-loop voltage gain Unity-gain bandwidth Maximum output voltage (Pin 2) Output source current (Pin 2) Pulse width modulation circuit section Common to FA5304AP(S) and FA5305AP(S) Item Input threshold voltage (Pin 2) Maximum duty cycle Soft-start circuit section Common to FA5304AP(S) and FA5305AP(S) Item ...
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... Output section Common to FA5304AP(S) and FA5305AP(S) Item L-level output voltage H-level output voltage Rise time Fall time Output ON/OFF control circuit section Common to FA5304AP(S) and FA5305AP(S) Item CS terminal source current OFF-to-ON threshold voltage (Pin 8) ON-to-OFF threshold voltage (Pin 8) Overall device Common to FA5304AP(S) and FA5305AP(S) ...
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... When the IC is powered up, CS pin voltage start operation. The output pulse then begins to widen gradually. During normal operation, the output pulse width is determined within the maximum duty cycle (FA5304A, FA5305A: 45%) set by DT voltage under the condition set by feedback signal , to stabilize the output voltage. ...
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... PWM comparator. The device is in soft-start mode while the CS pin voltage is between 1.0V and 1.9V common to FA5304A and FA5305A. During normal operation, the CS pin is clamped at 3.6V by internal zener diode Zn. If the output voltage drops due to an overload, etc., the clamp voltage shifts from 3 ...
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... A or more must be supplied by the optocoupler in order to raise the CS pin voltage above 7.0V. S =9V When the CS 6 below 8. Fig. 12 Overvoltage shutdown timing chart FA5304AP(S)/FA5305AP(S) Fig. 9 Overload shutdown circuit Fig. 10 Overload shutdown timing chart Fig. 11 Overvoltage shutdown circuit 7 ...
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... Overcurrent limiting circuit The overcurrent limiting circuit detects the peak value of every drain current pulse of the main switching MOSFET to limit the overcurrent. The detection threshold is 0.24V for FA5304A with respect to ground as shown in Figure 15. The drain current of the MOSFET is converted to voltage by resistor R and fed to the IS pin of the IC ...
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... The detection threshold is -0.17v for FA5305A with respect to ground as shown in Figure 17. The operation is similar to that of FA5304A except the threshold is minus voltage compared to that which is plus voltage for FA5304A. Figure timing chart which illustrates current limiting operations. 6. Undervoltage lockout circuit The IC incorporates a circuit which prevents the IC from malfunctioning when the supply voltage drops ...
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... FA5304AP(S)/FA5305AP(S) Design advice 1. Startup circuit It is necessary to start-up IC that the voltage inclination of VCC terminal “dVcc/dt” satisfies the following equation(4). dVcc/dt(V/s)>1.8/(Cs( F)).................................( capacitor connected between CS terminal and GND Note that equation (4) must be satisfied in any condition. Also necessary to keep “latch mode” for overload protection or ...
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... Startup circuit connected to rectified line This method is not suitable for FA5304A and FA5305A, especially concerned with re-startup operation just after power- off or startup which AC input voltage goes up slowly. Fig. 21 shows a startup circuit that a startup resistor R to rectified line directly. The period from power-on to startup is determined by R and C ...
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... Fig. 24 Disabling overload shutdown function Fig. 25 Independent setting of soft-start period and OFF latch delay . L Fig. 26 Vcc line and ground line for FA5304A Fig. 27 Vcc line and ground line for FA5305A CS VCC Fig. 28 Setting sink current for CS terminal 7.5k 18V Zener diode Under 500 A ...
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... OSC timing capacitor capacitance ( Output duty cycle vs. FB terminal voltage (V Output duty cycle vs. CS terminal voltage (V Oscillation frequency (f ambient temperature (Ta) ) Output duty cycle vs. FB terminal source current (Isource H-level output voltage (V CS output source current (I FA5304AP(S)/FA5305AP(S) ) vs. OSC ) vs SOURCE 13 ...
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... TH IS(–) ambient temperature (Ta) FA5305AP(S) IS (–) terminal current (I ) vs. IS(–) IS (–) terminal voltage (V ) IS(–) FA5305AP( (+) terminal threshold voltage (V ambient temperature (Ta) FA5304AP(S) ) vs. IS (+) terminal current (I IS (+) terminal voltage (V FA5304AP(S) CS terminal sink current (I CS terminal voltage (V ) vs. TH IS(+) ) vs. IS(+) ) IS(+) ) vs. SINK ...
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... Error amplifier frequency (f) vs. voltage gain (Av) /phase ( ) Supply current (I ) vs. supply voltage (V CC OFF or OFF latch mode Supply current (I Normal operation ) CC FA5304AP(S)/FA5305AP(S) ) vs. supply voltage ( ...
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... FA5304AP(S)/FA5305AP(S) Application circuit Example of FA5304AP(S) application circuit (1) Example of FA5304AP(S) application circuit (2) 16 ...
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... Example of FA5304AP(S) application circuit (3) Example of FA5305AP(S) application circuit 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. Fuji Semiconductor, Inc. - P.O. Box 702708 - Dallas, TX 75370 - 972-733-1700 - www.fujisemiconductor.com ...