L4973D3.3 STMicroelectronics, L4973D3.3 Datasheet

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Features ■ 3.5 A step down converter ■ Operating input voltage from ■ 3.3 V and 5.1 V (±1%) fixed output, and adjustable outputs from: – 0 (3.3 type) ...

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Contents Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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L4973 1 Block diagram Figure 2. Block diagram INH 10(11) ZERO CURRENT INHIBIT 17(19) SS 11(12) COMP 5.1V + 3.3V E/A VFB - 12(13) SYNC 18(20) Pin x = Powerdip Pin (x) = S020 2 Pin settings 2.1 Pin connection ...

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Pin settings 2.2 Pin description Table 1. Pin description N° Pin DIP- 7,8 2 4,5,6 13,14,15 14,15,16,17 1 Note: 1 The maximum power dissipation of the package must be observed. 4/28 Name SO-20 12 ...

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L4973 3 Electrical data 3.1 Maximum ratings Table 2. Absolute maximum ratings Symbol DIP-18 S0- ...

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Electrical characteristics 4 Electrical characteristics Table 4. Electrical characteristics (Refer to the test circuit,V R OSC Symbol Parameter Dynamic characteristics Input voltage range Output voltage L4973V5.1 Output voltage L4973V3.3 R DS(on ) Maximum limiting current η Efficiency Switching frequency Supply ...

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L4973 Table 4. Electrical characteristics (continued) (Refer to the test circuit,V R OSC Symbol Parameter Soft-start Soft-start charge current Soft-start discharge current Inhibit High level voltage Low level voltage I high level source I low level source DC characteristics Total ...

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Electrical characteristics Table 4. Electrical characteristics (continued) (Refer to the test circuit,V R OSC Symbol Parameter Maximum frequency Sync function High input voltage Low input voltage Slave sink current Master output amplitude I Output pulse width 1. Pulse testing with ...

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L4973 5 Evaluation board Figure 4. Evaluation board circuit SYNCH SYNCH Vin Vin R1 R1 15k 15k C10 C10 C9 C9 470u 63v 470u 63v 220n 220n 2.7n 2.7n 470n 470n NM NM GND ...

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... 6.7 A DO5040H-683MLD RMS SAT = 12 V OUT Description Resistor 2.7 kΩ 1% Resistor 1 kΩ 3.3 V OUT Description Resistor 2.7 kΩ 1% Not mounted = 5 V) (continued) Part number Manufacturer Nippon Chemi-con Nippon Chemi-con Coilcraft L4973V3.3 STMicroelectronics Part number Manufacturer Part number Manufacturer L4973 ...

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L4973 Figure 5. Evaluation board (components side) Figure 6. Evaluation board (solder side) Evaluation board 11/28 ...

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Application circuit 6 Application circuit Figure 7. Application circuit (see Figure 8. Application circuit (see 12/28 Figure 4 part list) INH SYNC R2 7 L4973V5 4,5 ...

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L4973 7 Typical characteristics Figure 9. Quiescent drain current vs. input voltage (0% duty cycle) Ibias (mA) 5.0 Tamb=25˚ 4.5 4.0 3.5 3.0 2.5 2 Figure 11. Stand by drain current vs. input voltage Ibias (μA) ...

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Typical characteristics Figure 13. Reference voltage vs. input voltage (pin 16) V REF (V) Tj=25˚C Pin 16 5.15 5.1 5.05 5 Figure 15. Inhibit current vs. inhibit voltage (pin 10) Iinh (μA) Vcc=35V Pin 10 100 50 0 ...

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L4973 Figure 17. Load regulation (see Figure V O (V) V 5.15 5.1 5.05 5 Figure 19. Load regulation (see Figure V O (V) V 3.35 3.34 3.33 3.32 3.31 3 Figure 18. Line regulation (see ...

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Typical characteristics Figure 21. Switching frequency vs. input voltage fsw (KHz) Tamb=25˚C 105 100 Figure 23. Dropout voltage between pin 7,8 and 2,3 ΔV (V) 0.6 0.4 0 16/28 Figure 22. Switching frequency ...

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L4973 Figure 25. Dropout voltage between pin 7,8 and 2,3 ΔV (V) 0.6 0.4 0 Figure 27. Efficiency vs. output voltage (Diode STPS745D) η (%) Figure 26. ...

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Typical characteristics Figure 29. Efficiency vs. output current (see η (%) 90 Vcc=24V Figure 31. Efficiency vs. output current (see η (%) 90 Vcc=12V 0.5 1 18/28 Figure 30. Efficiency ...

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L4973 Figure 33. Power dissipation vs. output voltage (device only) Pdiss (W) 3 35V 100KHz sw 2.5 2.0 1.5 1.0 0 Figure 35. Load transient ...

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Typical characteristics Figure 37. Source current rise and fall time, pin 2, 3 (see Figure 39. Soft-start capacitor selection vs. inductor and V AN938) Lomax (μ 200KHz sw 150 100 20/28 Figure 38. ...

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L4973 8 Application ideas Figure 41. 3 Figure 42 3.3 V high performance buck converter (fsw = 200 kHz 12V±5% 1.2nF C1 560uF-25V C2 HFQ 220nF Panasonic ...

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Application ideas Figure 43. Synchronization example V CC2 7,8 1 L4973 4,5,6 13,14,15 Figure 44. Multi output not isolated (pin out referred to DIP12+3+ < 20 22/28 ...

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L4973 9 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ...

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Package mechanical data Table 8. DIP-18 mechanical data Dim. Min a1 0. Figure 45. Package dimensions 24/28 mm. Typ Max Min 0.020 1.40 0.033 0.50 0.50 0.015 ...

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L4973 Table 9. SO-20 mechanical data Dim. Min A 2.35 A1 0.10 B 0.33 C 0.23 12.60 D ( 10.0 h 0.25 L 0.40 k ddd Figure 46. Package dimensions mm. Typ Max Min 2.65 0.093 ...

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... Order code 10 Order code Table 10. Order code L4973D3.3, E-L4973D3.3 L4973D3.3-013TR, E-L4973D3.3-TR L4973D5.1-013TR L4973V3.3, E-L4973V3.3 L4973V5.1, E-L4973V5.1 26/28 Part number L4973D5.1 Package Packaging SO-20 Tube SO-20 Tape and reel SO-20 Tube SO-20 Tape and reel DIP-18 Tube DIP-18 Tube L4973 ...

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L4973 11 Revision history Table 11. Document revision history Date 12-Sep-2001 07-May-2005 14-Dec-2005 06-Dec-2006 07-May-2007 26-Feb-2009 Revision 13 First Issue Updated the Layout look & feel. 14 Changed name of the D1 on the fig Added the ECOPACK ...

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