FA5526 Fuji Electric holdings CO.,Ltd, FA5526 Datasheet

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... Fuji Switching Power Control IC FA5526/5527/5528 FA5536/5537/5538 Application Note Rev.0.1 Jun 2007 FA5526/5527/5528/5536/5537/5538 1 February-2007 Fuji Electric Device Technology ...

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... If you have any question about any portion of this Data Book, ask Fuji Electric Device Technology Co., Ltd. or its sales agencies. Neither Fuji Electric Device Technology Co., Ltd. nor its agencies shall be liable for any injury or damage caused by any use of the products not in accordance with instructions set forth herein. Rev.0.1 Jun 2007 FA5526/5527/5528/5536/5537/5538 Warning 2 Fuji Electric Device Technology ...

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... 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 １ ...

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... Outline FA5526/27/28/36/37/38 series are current-mode switching power control ICs that can directly drive power MOSFETs. Low-power dissipation is achieved due to adoption of high break-down voltage CMOS process. In addition, stand-by power consumption can substantially be reduced due to a built-in start-up circuit. Many functions are incorporated in an eight pin package, reducing the number of external parts and allowing compact and high cost performance power supply 2 ...

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... Block diagram 5V reg 5V UVLO 4.0V/3.5V 2.9V 7.4k OverLoad FB (2) 60k 20k FA5526 / FA5527 / FA5528 for Timer Latched OCP 5V reg 5V UVLO 4.0V/3.5V 2.9V 7.4k OverLoad FB (2) 60k 20k FA5536 / FA5537 / FA5538 for Auto-Recovery OCP 5. Pin assignments Pin Symbol Function CS Soft start/latch-mode stop １ FB Feedback input ２ ３ IS Current sensor 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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... Condition MIN FA5526/36 117 FB=3V FA5527/37 90 FA5528/38 54 Vcc = 10 to 26V - -30 to 85℃ 0.95 FA5526/36 ⊿f/⊿VFB 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 THFB0 FB pin = 0V -620 fb0 7 ...

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... Charging current I Threshold voltage for V changing charging current Input threshold voltage V Over Current Protection circuit (CS pin) : Latch OFF for FA5526/27/28 and Auto-Recovery for FA5536/37/38 Item Charging current Sink current Cutoff threshold voltage Hysteresis width Clamp voltage at latch mode Cutoff circuit at overload (FB pin) ...

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... VH pin = 100V CCL 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 FA5527/37 FB pin CCOP1 =3V, FA5528/38 no load Duty cycle = 0％, CCOP2 FB pin = 0V FB pin, CS pin : open ...

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... IC characteristics and not for guaranteeing performance. Variation Ratio of Switching Frequency (delta fosc) vs. VCC pin voltage (Vcc) 2 1.5 1 0.5 0 -0 Vcc (V) Switching Frequency (fosc) vs. FB pin voltage 140 120 FA5526 / 36 100 FA5527 / FA5528 / 0.5 1 1.5 VFB (V) Maximum Duty Cycle (Dmax) vs. Junction Temperature (Tj) 81.0 80.5 80.0 79 ...

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... Vcs (V) UVLO ON threshold voltage (Vccon) vs. Junction Temperature (Tj) 16.0 15.8 15.6 15.4 15.2 15.0 14.8 14.6 14.4 14.2 14.0 -40 - (degree) Rev.0.1 Jun 2007 FA5526/5527/5528/5536/5537/5538 -3.5 CS=4V -4 -4.5 -5 -5.5 -6 -40 -20 80 100 120 140 CS pin current (Ics) vs. CS pin voltage (Vcs FB= -10 - 10.0 9.8 9.6 9 ...

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... IS pin maximum input threshold volatge(Vthis1) vs. Junction Temerature (Tj) 0.53 0.52 0.51 0.50 0.49 0.48 0.47 -40 - (degree) FB pin source current (IFB) vs. FB pin voltage (VFB) 0 -100 -200 -300 -400 -500 -600 VFB (V) Rev.0.1 Jun 2007 FA5526/5527/5528/5536/5537/5538 0.8 IOL = 100mA 0.7 0.6 0.5 0.4 0 0.6 Duty cycle = 50% 0.5 0.4 0.3 0.2 0 100 120 140 0 30.0 29.5 29.0 28.5 28.0 27.5 27.0 26 ...

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... Vcc (V) Start-up Circuit VCC pin Source Current vs. VH pin voltage (VVH) -6 -6.2 -6.4 -6.6 -6.8 -7 -7.2 -7.4 0 100 200 VVH (V) IS pin threshold voltage (Vthis) vs. Duty Cycle( pin = 3V for FA5528/5538 0.50 0.45 0.40 0.35 0. (%) Rev.0.1 Jun 2007 FA5526/5527/5528/5536/5537/5538 -5.5 -6.0 -6.5 -7.0 -7.5 -8 -40 0.60 Vcc = 0V 0.55 0.50 0.45 0.40 300 400 500 0 0.30 FB=3V 0.25 0.20 0.15 0. ...

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... Operating Mode Supply Current vs. VCC pin voltage (Vcc FA5526 / 36 1.6 FA5527 / 37 1.5 FA5528 / 38 1.4 1 Vcc (V) Rev.0.1 Jun 2007 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) Fuji Electric Device Technology ...

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... VH pin input current becomes 25uA (typ.). When IC enters to the latch mode due to any abnormal condition, the start-up circuit is activated again, the latch condition is maintained and Vcc voltage is held at approximately 23V. Here, FA5526/27/28 enters to the latch mode by overload ...

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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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... Consequently, the sum of blanking time and output delay time (100ns) is the minimum ON pulse width at the OUT pin of the IC. The minimum ON pulse width for FA5526/36, FA5527/37 and FA5528/38 are 300ns, 500ns and 700ns, respectively. ...

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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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... (OLP) stop period t (stop Cvcc [ Vcc(sw/OL) – Vccoff ] / ( I Here, Vcc(sw/OL) : Vcc in switching period at overload [ V ] Vccoff : OFF threshold voltage of U.V.L (typ.)) I : Consumption current in latch mode ( 290uA (typ.)) CCL FA5526/5527/5528/5536/5537/5538 Secondary Side DC Output Voltage FB pin Voltage CS pin Voltage the time from ...

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... Fig.17 Over-Voltage protection timing chart 21 Quality is our message Reg. Latch VCC 5V ENB 1.3mA 8.5V/7.7V 5V Reg. UVLO OVP UVLO 2.8V ENB 4.8V Overload F.F. ( only for FA5526 / 5527 / 5528 ) 28V 8.8V 8.5V Latch Off Over Voltage Detection ( only for FA5526 / 5527 / 5528 ) Fuji Electric Device Technology 6 VCC 28V OUT 5 ...

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... OUT pin are 0.25A for source current and 0.5A for sink current. If the IC stops operation when the under-voltage lockout circuit operates or in the latch mode, OUT pin voltage is forced to be low to shut down the MOSFET. (14) Timing chart FA5526/5527/5528/5536/5537/5538 Fig.18 Timing chart at steady operation 22 Quality is our message ...

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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 duty cycle operation Quality is our message Oscillator (OSC) ...

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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 width ( The sum of Blanking Time and Delay Time to OUT pin ) Fig ...

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... Vcc does not drop to the OFF threshold voltage in any condition. We recommend that you choose the capacitance connected to VCC pin so that the bottom of Vcc becomes larger than 11V as the result of typical experiment. FA5526/5527/5528/5536/5537/5538 Fig.22 CS pin voltage waveform at start-up (1) Secondary Side DC Output Voltage ...

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... In such a case, the circuit shown in Fig.28 is effective. Reducing C2 shortens start-up time, and hold time can be kept long because power is supplied via C4 after start-up. Fig.28 Vcc circuit FA5526/5527/5528/5536/5537/5538 Fig.25 Vcc waveform at start-up (2) （when the power supply can not start up） Secondary Side DC ...

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... ZD2 is cut VCC pin voltage decreases below OFF threshold ( FA5526/5527/5528/5536/5537/5538 Fig.29 Over Voltage protection (1) for FA5526/27/28 Fig.30 Over Voltage protection (2) for FA5526/27/28 Fig.31 Over Voltage protection (3) for FA5526/27/28 Fig.32 Over Voltage protection (1) for FA5536/37/38 27 Quality is our message Fuji Electric Device Technology ...

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... R5 is several hundreds of k ohm to several Meg ohm. Note that the above correction slightly decreases the value of overload current limit to stop the IC in the latch mode even if input voltage is low. FA5526/5527/5528/5536/5537/5538 Fig.33 Over Voltage protection (2) for FA5536/37/38 Fig.34 When not using overload protection Fig.35 Correction of overload detection current ...

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... IC. Pay full attention to capacitance and characteristics of the capacitor between the VCC pin and GND to reduce noise as much as possible. FA5526/5527/5528/5536/5537/5538 Fig.36 Input power improvement circuit at light load FA5526 /27/28/ 36/37/ Fig.37 Prevention of malfunction caused by noise Fig.38 Prevention of malfunction caused by noise ...

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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 pin, because the start-up time of IC may become too long when the circuit including a thermistor is connected to VCC pin of IC directly ...

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... When using FA5528 or FA5538, according to the specifications IHrun = 25uA = 0.025mA ( typ. ), Iccop1 = 1.4mA ( typ. ) and f = 60kHz = 0.06MHz ( typ.). Thus, typical IC loss Pd 18V * ( 1.4mA + 80nC * 0.06MHz ) + 119V * 0.025mA = 115mW ( typ. ) FA5526/5527/5528/5536/5537/5538 is VH pin VH 31 Quality is our message Fuji Electric Device Technology ...

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... Here, Lu：Gradient of an inductor current during the ON period Ld：Gradient of an inductor current during the OFF period Kc：Gradient of slope compensation The above parameters are shown in Fig.45. FA5526/5527/5528/5536/5537/5538 Fig.43 Inductor current without slope compensation Fig.44 Inductor current with slope compensation IL Slope : Lu Fig.45 Inductor current without slope compensation ...

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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 example of an application circuit is intended to be used only for reference and not to guarantee performance or characteristics ...