FA5527 FUJI [Fuji Electric], FA5527 Datasheet

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Fuji Switching Power Control IC FA5526/5527/5528 FA5536/5537/5538 Application Note Fuji Electric Co., Ltd. AN-087E Rev.1.0 April-2011 FA5526/5527/5528/5536/5537/5538 1 April.-2011 Fuji Electric Co., Ltd. http://www.fujielectric.co.jp/products/semiconductor/ ...

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This Data Book contains the product specifications, characteristics, data, materials and structures as of April in 2011. The contents are subject to change without prior notice for specification changes or other reasons. When using a product listed in this ...

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Outline 2． Features 3． External dimension diagram 4． Block diagram 5． Pin assignments 6． Selection Guide of FA5526/27/28/36/37/38 series 7． Ratings and characteristics 8． Characteristic curves 9． Description of block circuits 10． Design advice 11． Examples of application circuits ...

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... Supply Current in Operating Mode : 1.4mA (typ.) ( for FA5528 and FA5538 ) ▪ Built-in frequency-decreasing function at light load ▪ Oscillating frequency FA5526/5536 : 130kHz(typ.), FA5527/5537 : 100kHz(typ.), FA5528/5538 : 60kHz(typ.) ▪ Built-in latch-mode cutoff function of overload ( over current ) for FA5526/5527/5528 ▪ Built-in Auto-Recovery cutoff function of overload ( over current ) for FA5536/5537/5538 ▪ ...

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... Block diagram 5V reg 5V UVLO 4.0V/3.5V 2.9V 7.4k OverLoad FB (2) 1Meg 60k 20k FA5526 / FA5527 / FA5528 for Timer Latched OCP 5V reg 5V UVLO 4.0V/3.5V 2.9V 7.4k OverLoad FB (2) 1Meg 60k 20k FA5536 / FA5537 / FA5538 for Auto-Recovery OCP 5. Pin assignments Pin Symbol Function 1 CS Soft start/latch-mode stop 2 FB Feedback input ...

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... Line-up of FA5526/27/28/36/37/38 series Type Switching Frequency (kHz) FA5526P/N 130 (typ.) FA5527P/N 100 (typ.) FA5528P/N 60 (typ.) FA5536P/N 130 (typ.) FA5537P/N 100 (typ.) FA5538P/N 60 (typ.) 7. Ratings and characteristics ＊In defining a current, “＋” represents a sink current and “－” a source current. ...

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... FA5526/36 117 FB=3V FA5527/37 90 FA5528/38 54 Vcc = 10 to 26V - -30 to 85℃ 0.95 ⊿ f/⊿ VFB FA5526/36 FA5527/ pin =0.8V FA5528/38 to 0.9V FA5526/36 FB pin FA5527/37 =0.6V FA5528/38 0.4 Condition MIN FB pin = 3V, CS pin = 3V 76 MAX FB pin = 0V, CS pin = 3V MIN Duty cycle = 0% 200 FB pin = 0V -620 7 MAX Unit 26 V 450 ...

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... VFB/⊿ VIS 3 pin = 4V, duty = 10% 470 IS1 FA5526/36 FB pin=4V FA5527/37 FA5528/38 FA5526/36 FB pin=3V FA5527/37 CS pin=0V IS pin=1V FA5528/38 FA5526/36 FA5527/37 FA5528/38 IS pin to OUT pin IS Condition MIN CS pin = 0V -15 Ics = -12  -4µA OUT pin width = Tmin, FB pin = 3V Symbol Condition MIN I CS pin = 4V -6 ...

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... VH pin = 100V Vcc = 10V, VH pin = 100V at start-up or protection mode ( OCP, OVP ) Vcc = 13V, VH pin = 100V at start-up or protection mode ( OCP, OVP ) Condition MIN Duty cycle FA5526/ MAX FB pin FA5527/37 =3V, FA5528/38 no load Duty cycle = 0％, FB pin = 0V FB pin, CS pin : open Iz = 2mA 9 TYP MAX Unit 15.0 16.8 V 9.0 10 ...

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... Junction Temperature (Tj 100 120 140 Tj (degree) Minimum Switching Frequency (fmin) vs. Junction Temperature (Tj) - 100 120 140 Tj （ degree ） Minimum ON Width (Tmin) vs. Junction Temperature (Tj) FA5528 / 38 FA5527 / 37 FA5526 / 100 120 140 Tj（degree） http://www.fujielectric.co.jp/products/semiconductor/ ...

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CS pin source current (Ics) vs. Junction Temperature (Tj) -9 CS=0V -10 -11 -12 -13 -14 -40 - （degree） CS pin current (Ics) vs. CS pin voltage (Vcs FB=open ...

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OUT pin High Output Voltage (VOH) vs. VCC pin Voltage (Vcc) 3 IOH = -100mA 2 Vcc (V) IS pin maximum input threshold volatge(Vthis1) vs. Junction Temerature (Tj) 0.53 0.52 0.51 0.50 0.49 0.48 ...

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Start-up Circuit VCC pin Source Current (Ipre) vs. VCC pin voltage (Vcc) -5.0 VVH = 100V -5.5 -6.0 -6.5 -7.0 -7.5 -8 Vcc (V) Start-up Circuit VCC pin Source Current vs. VH pin voltage (VVH) -6 -6.2 Vcc ...

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... Operating Mode Supply Current vs. VCC pin voltage (Vcc) 1.7 FA5526 / 36 1.6 FA5527 / 37 1.5 FA5528 / 38 1.4 1 Vcc (V) Fuji Electric Co., Ltd. AN-087E Rev.1.0 April-2011 FA5526/5527/5528/5536/5537/5538 1.7 1.6 1.5 1.4 1.3 -40 - Operating Mode Supply Current (Iccop1) vs. Junction Temperature (Tj) FA5526 / 36 FA5527 / 37 FA5528 / 100 120 140 Tj (degree) http://www.fujielectric.co.jp/products/semiconductor/ ...

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Description of block circuits (1) Start-up circuit The FA5526/27/28/36/37/38 has built-in start-up circuits with maximum rated voltage of 500V. Wiring is shown in Figs When power is turned on, a current is supplied to the VCC pin ...

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... Oscillator The oscillator determines switching frequency. For steady operation at heavy load, the oscillating frequency is set at 130kHz for FA5526/36, 100kHz for FA5527/37 or 60kHz for FA5528/38 inside the IC. In addition, the IC has a function to automatically decrease oscillating frequency at light load to reduce standby power dissipation. When FB pin voltage becomes 1 ...

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... As a result, the IS pin input voltage is ignored for a blanking time (200ns for FA5526/36, 400ns for FA5527/37 and 600ns for FA5528/38) immediately after an output pulse has been generated from the OUT pin and does not respond to a surge current at turn-on. ...

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... Slope compensation In the current mode control, subharmonic oscillation may occur at a continuous current mode operation with a duty cycle of 50% or more. To avoid this, FA5526/36, FA5527/37 and FA5528/38 have built-in slope compensation circuits. For details of subharmonic oscillation phenomenon and slope compensation effect, see p.32. ...

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... CS pin voltage is 0.68V or less, same as FB pin. (See “9-(14) Timing chart.”) (8) Overload protection of FA5526/27/28 FA5526, FA5527 and FA5528 have built-in time-latch type overload protection. Fig.12 shows its block diagram and Fig.13 its Timing chart. In steady operation, FB pin voltage less and CS pin voltage is clamped zener diode in the IC ...

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When the output voltage momentarily drops due to abrupt load change and FB pin voltage restores to the voltage at steady state before CS pin voltage reaches 8.5V, the 4V clamp circuit restarts, producing no latch mode. The latch mode ...

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... Over-Voltage Protection of FA5526/27/28 FA5526, FA5527 and FA5528 have built-in over-voltage protection circuits to monitor Vcc voltage. Fig.16 shows its block diagram and Fig.17 its timing chart. When VCC voltage increases and exceeds comparator (OVP) reference voltage, 28V, an internal 1.3mA constant current source is tuned on. ...

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Output circuit The output circuit consists of push-pull configuration, capable of directly driving a MOSFET. The maximum peak currents at the OUT pin are 0.25A for source current and 0.5A for sink current. If the IC stops operation when ...

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FA5526/5527/5528/5536/5537/5538 Oscillator (OSC) Trigger (T) Output Blanking CLR Signal Blanking Output signal (set pulse) FB pin Voltage IS pin Voltage IS comp. output (reset pulse) FF “Q” output OSC Q output OUT pin Output voltage Fig.19 Timing chart at maximum ...

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FA5526/5527/5528/5536/5537/5538 Oscillator (OSC) Trigger (T) Output Blanking CLR Signal Blanking Output signal (set pulse) FB pin Voltage CS pin Voltage IS pin Voltage IS comp. output (reset pulse) FF “Q” output OSC Q output OUT pin Output voltage Minimum ON ...

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Start-up and stop To properly start up and stop the power supply, optimum values shall be set for capacitors connected to the CS pin and VCC pin. (1-1) At start-up (1) It takes certain time until the ...

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When Vcc capacitance is too small, Vcc drops to the OFF threshold voltage as shown in Fig.25 before the auxiliary winding voltage increases sufficiently. In this case, Vcc repeatedly goes up and down between the ON and OFF threshold voltages, ...

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Protection using CS pin for FA5526/27/28 In steady operation, the CS pin voltage is clamped zener diode. Externally forcing CS pin voltage to increase to the threshold voltage, 8.5V, for the latch mode allows the IC ...

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When not using an overload protection function As shown in Fig.34, connect a resistor R3 of 18k ohm between FB pin and GND result, FB pin voltage does not increase to the threshold voltage for overload protection ...

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Improvement of input power at light load This IC is provided with a function to lower switching frequency at light load in order to reduce power dissipation. However, depending on the circuit used, switching frequency cannot be sufficiently reduced, ...

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Over Temperature Protection as latch mode for FA5526 / Over Temperature Protection as latch mode can be achieved by the circuit shown in Fig.39 for FA5526/27/28. Here, a diode D1 connected to separated line from VCC ...

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Loss calculation IC loss shall be determined to use the IC within its rating. Since it is hard to directly measure IC loss, an example of calculating approximate IC loss is given below. Total IC loss, Pd, is obtained ...

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Sub-harmonic oscillation and slope compensation In a peak-value-control current mode, when the converter operates in an inductor-current continuous mode and at duty cycle of 50% or more, the current may oscillate at an integral multiple of switching frequency. This ...

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Example of an application circuit The following circuit is common to both of FA5528 and FA5538. FA5526/27/28/36/37/38 can be used for same topology except the protection circuit and the transformer design which depends on switching frequency. Note : The ...