UC2842 STMicroelectronics, UC2842 Datasheet
UC2842
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UC2842 Summary of contents
Page 1
... BLOCK DIAGRAM (toggle flip flop used only in U3844 and UC3845) October 1998 UC2842/3/4/5 UC3842/3/4/5 CURRENT MODE PWM CONTROLLER Minidip logic to insure latched operation, a PWM compara- ...
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... UC2842N UC2843N UC2844N UC2845N UC3842N UC3843N UC3844N UC3845N Min id ip max. Value Unit 30 V Self Limiting – 0 725 mW – 150 C 300 C Minidip SO14 UC2842D UC2843D UC2844D UC2845D UC3842D UC3843D UC3844D UC3845D SO14 Unit 100 165 C ...
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... Input Bias Current b Delay to Output I Output Low Level OL I Output High Level OH t Rise Time r t Fall Time f UC2842/3/4/5-UC3842/3/4/5 = 15V (note 5 10K UC284X T est Cond ition s Min. T yp. Max. Min. Typ . Max. REFERENCE SECTION 4.95 5.00 5.05 4.90 5.00 5. 1mA ...
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... UC2842/3/4/5-UC3842/3/4/5 ELECTRICAL CHARACTERISTICS (continued) Symbo l Parameter UNDER-VOLTAGE LOCKOUT SECTION Start Threshold Min Operating Voltage After Turn-on Maximum Duty Cycle Minimum Duty Cycle I Start-up Current st I Operating Supply Current i V Zener Voltage iz N otes : 2. These parameters, although guaranteed, are not 100% tested in production. ...
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... Pin 6 should be shunted to groundwith a bleederresistor Figure 3 : Current Sense Circuit . Peak current ( determined by the formula s 1 max small RC filter may be required to suppress switch transients. UC2842/3/4/5-UC3842/3/4/5 to preventactivating the power switch with extrane- ous leakage currents. 5/11 ...
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... UC2842/3/4/5-UC3842/3/4/5 Figure 4. 1.72 for R > Figure 6 : Timing Resistance vs. Frequency. Figure 8 : Error Amplifier Open-loop Frequency Response. 6/11 Figure 5 : Deadtime vs > Figure 7 : Output Saturation Characteristics. ...
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... Timing and bypass capacitors should be connected close Figure 10 : Shutdown Techniques. Shutdown of the UC2842 can be accomplished by two methods; either raise pin 3 above1V or pull pin 1 below a voltage two diode drops above ground. Either method cause the output of the PWM com- parator to be high (refer to block diagram) ...
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... UC2842/3/4/5-UC3842/3/4/5 Figure 11 : Off-line Flyback Regulator. Power Supply Specifications 1. Input Voltage : 95 VAC to 130 VAC (50 Hz/60 Hz) 2. Line Isolation : 3750 V 3. Switching Frequency : 40 KHz 4. Efficiency @ Full Load : 70 % Figure 12 : Slope Compensation. A fraction of the oscillator ramp can be resistively summed with the current sense signal to provide slope compensation for converters requiring duty cycles over 50 % ...
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... D and F do not include mold flash or protrusions. Mold flash or potrusions shall not exceed 0.15mm (.006inch). inch OUTLINE AND TYP.. MAX.. MECHANICAL DATA 0.069 0.009 0.063 0.018 0.010 0.020 0.344 0.244 0.050 0.300 0.157 0.209 0.050 0.027 UC2842/3/4/5-UC3842/3/4/5 SO14 9/11 ...
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... UC2842/3/4/5-UC3842/3/4/5 mm DIM. MIN. TYP. MAX. MIN. A 3.3 a1 0.7 0.028 B 1.39 1.65 0.055 B1 0.91 1.04 0.036 b 0.5 b1 0.38 0.5 0.015 D 9.8 E 8.8 e 2.54 e3 7.62 e4 7.62 F 7.1 I 4.8 L 3.3 Z 0.44 1.6 0.017 10/11 inch OUTLINE AND TYP. MAX. MECHANICAL DATA 0.130 0.065 0.041 0.020 0.020 0.386 0.346 0.100 0.300 0.300 0.280 0.189 0.130 Minidip 0.300” ...
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... The ST logo is a registered trademark of STMicroelectronics 1998 STMicroelectronics – Printed in Italy – All Rights Reserved STMicroelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Mexico - Morocco - The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. UC2842/3/4/5-UC3842/3/4/5 http://www.st.com 11/11 ...