SA57250-50GW NXP Semiconductors, SA57250-50GW Datasheet
SA57250-50GW
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SA57250-50GW Summary of contents
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... SA57250-XX CMOS switching regulator (PWM controlled) Product data Supersedes data of 2001 Aug 01 INTEGRATED CIRCUITS 2003 Nov 12 ...
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... The regulator has a high precision output with 2.4% accuracy. Few external components are required. The SA57250 has an ON/OFF control that may be used to turn off the converter and conserve power in battery powered applications. Power off supply current is no more than 0 built-in, soft-start circuit reduces current inrush and voltage overshoot during start up ...
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... Part number marking Each device is marked with a four letter code. The first three letters designate the product. The fourth letter, represented by ‘x’ date tracking code. Part number SA57250-20GW SA57250-25GW SA57250-28GW SA57250-30GW SA57250-33GW SA57250-36GW SA57250-50GW PIN DESCRIPTION PIN SYMBOL 1 ON/OFF ...
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... OUT V = output voltage 0.95 – OUT I = 1.0 mA – OUT ON/OFF pin = 0 V – output voltage 0.95 – OUT V = output voltage 0.95 – OUT -20 -25 -28 -30 -33 -36 -50 4 Product data SA57250-XX MIN. TYP. MAX. UNIT – – 9.0 V – – 0.9 V 0.7 – 0.8 V 0.7 – – V – 11.6 19.4 A – 14.3 23.9 A – 16.1 26 ...
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... SL01458 Figure 6. Supply current 1, 2 versus amb 60 f (kHz) OSC SL01462 . Figure 8. Oscillator frequency versus V OUT 5 Product data SA57250- 100 T C) amb SL01457 (V) OUT SL01459 . OUT ...
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... Figure 12. Start-up characteristic mA 1.8 V OUT IN I OUT LOAD CURRENT (20 mA/div) V OUT OUTPUT VOLTAGE (50 mV/div) SL01476 : 0 V 3.0 V. Figure 14. Output load regulation, increasing current. 6 Product data SA57250- 1 (10 s/div) SL01473 = 10 mA. OUT OUT t (1 ms/div) SL01475 : 100 1.8 V ...
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... V ST1 100 0.0 0.5 SL01482 Figure 20. Input voltage versus supply current. 7 Product data SA57250- 1 OUT t (100 s/div) SL01479 V ST1 OUTPUT CURRENT (mA) OUT ...
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... F). 0 OUT 2003 Nov 12 100 100 1000 0.01 0.1 SL01484 Figure 22. Output current versus efficiency (100 H inductor). 100 1000 SL01486 8 Product data SA57250 100 1000 I , OUTPUT CURRENT (mA) OUT SL01485 ...
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... Each device is set to provide a fixed output voltage by having a fully compensated internal voltage feedback loop. The SA57250-XX operates at a fixed frequency of 50 kHz and can operate from a single alkaline cell (0 The SA57250-XX has an internal common-source power switching MOSFET that provides the PWM signal to the boost inductor ...
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... Philips Semiconductors CMOS switching regulator (PWM controlled) APPLICATION INFORMATION The SA57250-XX can be used for a simple boost (step-up) converter or the less commonly used flyback converter (isolated boost). The major operating restriction of the simple boost converter is that its output voltage must always be above the highest expected value of the input voltage ...
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... SPIKE +V IN ENERGY BEING ENERGY BEING STORED IN TRANSFERRED INDUCTOR TO OUTPUT – peak IN OUT L 0 Figure 27. Continuous mode waveforms. 11 Product data SA57250-XX —This period as displayed in Figure 26 occurs and any parasitic inductances and 0 —If the inductor is not completely emptied of its +V OUT SL01465 ...
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... CMOS switching regulator (PWM controlled) Determining the value of the boost inductor The precise value of the boost inductor is not critical to the operation of the SA57250-XX. The value of the boost inductor should be calculated to provide continuous-mode operation over most of its operating range. The converter may enter the discontinuous-mode when the output load current falls to less than about 20 percent of the full-load current ...
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... The 1:1 turns ratio should work for output voltages from 0 times the highest input voltage, and produce the output voltage set by the SA57250-XX. The only other restriction is that the input voltage plus the output voltage must be less than the breakdown voltage of the SA57250- ...
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... snubber This should produce a snubber that does not load the circuit and introduces a very small loss. 2003 Nov 12 V BATT ON/OFF ). 0 Figure 30. Passive snubber in flyback converter. Eqn. (10) 14 Product data SA57250-XX PASSIVE SNUBBER V OUT SA57250-XX GND SL01469 ...
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... The major sources of heat within the converter are the power switch inside the SA57250-XX, the resistive losses within the inductor, and losses associated with the output rectifier. These losses can be estimated by the following equations: ...
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... Philips Semiconductors CMOS switching regulator (PWM controlled) PACKING METHOD The SA57250-XX is packed in reels, as shown in Figure 32. GUARD TAPE BAND BARCODE LABEL BOX 2003 Nov 12 REEL ASSEMBLY Figure 32. Tape and reel packing method 16 Product data SA57250-XX TAPE DETAIL COVER TAPE CARRIER TAPE SL01305 ...
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... Philips Semiconductors CMOS switching regulator (PWM controlled) Plastic small outline package; 5 leads; body width 1.6 mm 2003 Nov 12 17 Product data SA57250-XX SOP003 ...
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... Relevant changes will be communicated via a Customer Product/Process Change Notification (CPCN). Fax: + 24825 Document order number: 18 Product data SA57250-XX Koninklijke Philips Electronics N.V. 2003 All rights reserved. Printed in U.S.A. Date of release: 11-03 9397 750 12323 ...