FA13842 Fuji Electric holdings CO.,Ltd, FA13842 Datasheet
FA13842
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FA13842 Summary of contents
Page 1
... FA13843N FA13844P 16. FA13844N FA13845P 9. FA13845N Dimensions, mm SOP-8 0.4 DIP Maximum duty Package 96% DIP SOP 96% DIP SOP 2.54 48% DIP SOP 48% DIP SOP CMOS IC FA13842, 13843, 13844, 13845 For Switching Power Supply Control 4.9 0.1 0.2 1. 9.3 1.5 7.62 0.25 0.1 0.46 1 ...
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... FA13842, 13843, 13844, 13845 Block diagram FA13842, 13843 VCC 7 UVLO VCC 5V REF 30V ENB 2.5V UVLO RT/CT OSC 4 ER AMP COMP ISNS 3 5V Controlled block FA13844, 13845 VCC 7 UVLO VCC 5V REF 30V ENB 2.5V UVLO RT/CT 4 OSC ER AMP COMP ISNS 3 5V ControlIed block Absolute maximum ratings (Ta=25˚ ...
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... COMP=2.5V, Tj=25˚C 2.4 65 0.7 FB=2.3V, COMP=0V –0.8 FB=2.7V, COMP=1V 2 FB=2.3V, R =15k to GND 4.0 L FB=2.7V, R =15k to VREF L Test condition Min. Tj=25˚C 2.85 FB=0V 0.9 Tj=25˚C, ISNS to OUT FA13842, 13843, 13844, 13845 Unit kHz Typ. Max. Unit 5.00 5. 0.3 mV/˚ Typ. Max. ...
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... FA13842, 13843, 13844, 13845 Output section Item Symbol High-level output V OH Low-level output V OL Rise time tr Fall time tf Under-voltage lockout section Item Symbol Start threshold Min. operating voltage V TH OFF Hysteresis V HYS PWM section Item Symbol Maximum duty cycle Dmax Minimum duty cycle ...
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... Output dead time vs. oscillation frequency FA13844, FA13845 100 100 1000 Output max. duty cycle vs. timing resistance FA13842, FA13843 100 100 150 FA13842, 13843, 13844, 13845 = 15V 2.2nF C =10nF T 100 Oscillation frequency (kHz 15V CC Ta= 25˚C 2.2nF C =10nF T 100 Oscillation frequency (kHz timing resistance ( 470pF ...
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... FA13842, 13843, 13844, 13845 ISNS threshold voltage vs. COMP voltage 1200 V = 15V CC FB= 0V 1000 OUT= off 800 600 400 200 COMP voltage (V) COMP to ISNS offset voltage vs. temperature 2.5 2 1.5 1 0.5 0 – Temperature (˚C) Error amp open loop voltage gain and phase vs. ...
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... VCC voltage (V) Output waveform Vcc=15V, OUT CL=1nF, Ta=25˚ 15V CC OUT CL= 1nF Ta= 25˚C 25.0ns 2.50V FA13842, 13843, 13844, 13845 VCC startup current vs. VCC supply voltage FA13842, FA13844 14 Ta= 25˚ 14.5 30 Vcc=15V, OUT CL=2.2nF, Ta=25˚ 15V CC OUT CL= 2.2nF Ta= 25˚C 2 ...
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... CC REF The threshold level of the V comparator is set at 16.5V/9V for CC FA13842/44 and 9.6V/9V for FA13843/45. In the standby mode, in which the V is under ON threshold, the power CC supply current is maintained at nearly 0 (zero). However, a maximum current required to change from standby mode to operating mode . ...
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... Synchronized operation is started when the RT/CT terminal voltage is raised to about 3V or higher. (Synchronized at leading edge.) The external synchronizing signal should be higher than the free-run frequency. In the case of FA13844/45, the output frequency of the OUT terminal is 1/2 that of the synchronizing signal frequency. FA13842, 13843, 13844, 13845 INPUT ~ is ...
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... FA13842, 13843, 13844, 13845 Latched shutdown 3. A typical circuit for latched shutdown is shown in Fig. 8. The voltage of the OUT terminal is kept low if the voltage of the COMP terminal is low. The voltage of the COMP terminal must be set at 0.7V or less in the application temperature range. (See characteristic curve on page 46 ”COMP to ISNS offset voltage vs temperature” ...
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... The method of detecting an overcurrent (detection of secondary current) A typical secondary overcurrent detection circuit is shown in Fig. 14 INPUT ~ ZD1 FA13842 Tr2 Tr1 R3 C6 Fig INPUT R4 Tr1 MOSFET Rs AC INPUT R6 R4 Tr2 Tr1 C6 FA13842, 13843, 13844, 13845 FA13842 MOSFET Tr2 D5 PC1 Fig INPUT FA13842 ...
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... FA13842, 13843, 13844, 13845 4. Soft start A soft-start circuit is shown in Fig. 15. An aproximate soft-start time is determined with the following calculation. This soft-start time is defined as the time the ISNS terminal threshold voltage increases from 0V to 1V. t [ms]=4.3•C9[ F] soft-start 5. Suppression of noise at the current sensing ...
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... OFF same T, Is, Lu and –Ld assumed in Fig. 21 that the inductor current varies t0, the variation i ’ of the inductor current larger than t0. Thereafter, this inductor current variation gradually L increases, and as a result, subharmonic oscillation occurs. FA13842, 13843, 13844, 13845 1 C11 2R PC2 R19 2.5V 3 ...
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... FA13842, 13843, 13844, 13845 Fig. 22 illustrates a case when the inductor current variation i ’ smaller than i at t0. In this case, inductor current L L variations gradually converges and the inductor current becomes stable necessary to apply slope compensation to the control signals in order to prevent such subharmonic oscillations when the inductor current is continuous and the duty cycle is greater than 50% ...
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... F D9 ERA22-10 MOSFET 2SK2101 R29 R30 4.7k 33 R31 D11 100 ERA91-02 VREF 8 OUT OUTPUT 6 ENB GND C14 0.1 F FA13842, 13843, 13844, 13845 L1 YG902C 3 4700 F 2 R27 100k C17 + + + C7 C18 1000 F C15 470pF R28 R20 D10 1k 1.2k ERA22-10 R32 Rs 2.2k PC2 0.33 ...