SA57254-20GW NXP Semiconductors, SA57254-20GW Datasheet
SA57254-20GW
Related parts for SA57254-20GW
SA57254-20GW Summary of contents
Page 1
... SA57254-XX CMOS switching regulator (PWM controlled) Product data Supersedes data of 2001 Aug 01 INTEGRATED CIRCUITS 2003 Nov 11 ...
Page 2
... PWM control. The regulator has a high precision output with 2.4% accuracy. Few external components are required. The SA57254-XX has a built-in soft-start circuit which reduces inrush current and voltage overshoot during start-up. A low resistance CMOS power FET, which has low leakage current and low parasitic capacitance, is on-chip ...
Page 3
... Power dissipation D 2003 Nov 11 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 SA57254-20GW SA57254-25GW SA57254-28GW SA57254-30GW SA57254-33GW SA57254-36GW SA57254-50GW PIN DESCRIPTION ...
Page 4
... OUT OUT – +85 C – amb V = output voltage 0.95 – OUT V = output voltage 0.95 – OUT I = 1.0 mA – OUT -20 -25 -28 -30 -33 -36 -50 4 Product data SA57254-XX MIN. TYP. MAX. UNIT – – 9.0 V – – 0.9 V – – 0.8 V 0.7 – – V – 11.6 19.4 A – 14.3 23.9 A – 16.1 26 ...
Page 5
... SL01458 Figure 6. Supply current 1, 2 versus amb 60 f (kHz) OSC SL01462 . Figure 8. Oscillator frequency versus V OUT 5 Product data SA57254- 100 T C) amb SL01457 (V) OUT SL01459 . OUT ...
Page 6
... V/div) SL01472 = 200 A. Figure 10. Ripple voltage 1 INPUT VOLTAGE (1 V/div) V OUT OUTPUT VOLTAGE (1 V/div) SL01474 = 60 mA. Figure 12. Start-up characteristic SL01477 6 Product data SA57254- 1 (10 s/div) SL01473 = 10 mA. OUT OUT t (1 ms/div) SL01475 : ...
Page 7
... V ST1 100 0.0 0.5 SL01482 Figure 19. Input voltage versus supply current. 7 Product data SA57254- 1 OUT t (100 s/div) SL01479 V ST1 OUTPUT CURRENT (mA) OUT ...
Page 8
... F). 0 OUT 2003 Nov 11 100 100 1000 0.01 0.1 SL01484 Figure 21. Output current versus efficiency (100 H inductor). 100 1000 SL01486 8 Product data SA57254 100 1000 I , OUTPUT CURRENT (mA) OUT SL01485 ...
Page 9
... The SA57254- highly integrated boost-mode switching power supply integrated circuit. Each device is set to provide a fixed output voltage by having a fully compensated internal voltage feedback loop. The SA57254-XX operates at a fixed frequency of 50 kHz and can operate from a single alkaline cell (0 ...
Page 10
... Philips Semiconductors CMOS switching regulator (PWM controlled) APPLICATION INFORMATION The SA57254-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 ...
Page 11
... SPIKE +V IN ENERGY BEING ENERGY BEING STORED IN TRANSFERRED INDUCTOR TO OUTPUT – peak IN OUT L 0 Figure 26. Continuous mode waveforms. 11 Product data SA57254-XX —This period as displayed in Figure 25 occurs and any parasitic inductances and 0 —If the inductor is not completely emptied of its +V OUT SL01465 ...
Page 12
... 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 SA57254-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 ...
Page 13
... 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 SA57254-XX. The only other restriction is that the input voltage plus the output voltage must be less than the breakdown voltage of the SA57254- ...
Page 14
... R snubber This should produce a snubber that does not load the circuit and introduces a very small loss. 2003 Nov 11 V BATT Figure 29. Flyback converter with passive snubber. Eqn. (10) 14 Product data SA57254-XX PASSIVE SNUBBER V OUT SA57254-XX GND SL01506 ...
Page 15
... The major sources of heat within the converter are the power switch inside the SA57254-XX, the resistive losses within the inductor, and losses associated with the output rectifier. These losses can be estimated by the following equations: ...
Page 16
... Philips Semiconductors CMOS switching regulator (PWM controlled) PACKING METHOD The SA57254-XX is packed in reels, as shown in Figure 31. GUARD TAPE BAND BARCODE LABEL BOX 2003 Nov 11 REEL ASSEMBLY Figure 31. Tape and reel packing method. 16 Product data SA57254-XX TAPE DETAIL COVER TAPE CARRIER TAPE SL01305 ...
Page 17
... Philips Semiconductors CMOS switching regulator (PWM controlled) Plastic small outline package; 5 leads; body width 1.6 mm 2003 Nov 11 17 Product data SA57254-XX SOP003 ...
Page 18
... Relevant changes will be communicated via a Customer Product/Process Change Notification (CPCN). Fax: + 24825 Document order number: 18 Product data SA57254-XX Koninklijke Philips Electronics N.V. 2003 All rights reserved. Printed in U.S.A. Date of release: 11-03 9397 750 12317 ...