Datasheet

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This is information on a product in full production.

November 2013 DocID2141 Rev 13 1/22

L4940

1.5 A very low drop voltage regulator IC

Datasheet

production data

Features

• Precise 5, 8.5, 12 V outputs

• Low dropout voltage (450 mV typ. at 1 A)

• Very low quiescent current

• Thermal shutdown

• Short-circuit protection

• Reverse polarity protection

Description

The L4940 series of three-terminal positive

regulators is available in TO-220 and D²PAK

packages and with several fixed output voltages,

making it useful in a wide range of industrial and

consumer applications. Thanks to their very low

input/output voltage drop, these devices are

particularly suitable for battery-powered

equipment, reducing consumption and prolonging

battery-life. Each type employs internal current

limiting, anti-saturation circuit, thermal shutdown

and safe area protection.

TO-220

D²PAK

Table 1. Ordering table

Order codes

Output

voltages

TO-220 D²PAK

L4940V5 L4940D2T5-TR 5 V

L4940V85 8.5 V

L4940D2T12-TR 12 V

www.st.com

Summary of content (22 pages)

PAGE 1
L4940 1.5 A very low drop voltage regulator IC Datasheet - production data Table 1. Ordering table Order codes TO-220 D²PAK L4940V5 L4940D2T5-TR L4940V85 5V 8.5 V L4940D2T12-TR TO-220 Output voltages 12 V D²PAK Features • Precise 5, 8.5, 12 V outputs • Low dropout voltage (450 mV typ.
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Contents L4940 Contents 1 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Test circuits 5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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L4940 1 Block diagram Block diagram Figure 1.
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Pin configuration 2 L4940 Pin configuration Figure 2.
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L4940 3 Maximum ratings Maximum ratings Table 2. Absolute maximum ratings Symbol VI VIR Parameter Value Unit 30 V VO = 5 V, RO = 100 Ω -15 V VO = 8.
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Test circuits 4 L4940 Test circuits Figure 3. DC parameters Figure 4. Load regulation Figure 5.
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L4940 5 Electrical characteristics Electrical characteristics Refer to test circuit, VI = 7 V, CI = 0.1 µF, CO = 22 µF, TJ = 25 °C, unless otherwise specified. Table 4. L4940#5 electrical characteristics Symbol Parameter Test conditions Min. Typ. Max. Unit VO Output voltage IO = 500 mA 4.9 5 5.1 V VO Output voltage IO = 5 mA to 1.5 A, VI = 6.5 to 15 V 4.8 5 5.
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Electrical characteristics L4940 Table 5. L4940#85 electrical characteristics (continued) Symbol Parameter Test conditions Min. ΔVO / ΔT Output voltage drift SVR Supply voltage rejection Vd Dropout voltage Isc Short-circuit current f = 120 Hz, IO = 1 A 58 Typ. Max. Unit 0.8 mV/°C 66 dB IO = 0.5 A 200 400 mV IO = 1.5 A 500 900 mV VI = 14 V 2 2.7 2.2 2.9 A VI = 10.2 V Refer to test circuit, VI = 14 V, CI = 0.1 µF, CO = 22 µF, TJ = 25 °C, unless otherwise specified. Table 6.
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L4940 6 Performance characteristics Performance characteristics Figure 6. Dropout voltage vs. output current Figure 7. Dropout voltage vs. temperature Figure 8. Output voltage vs. temperature (L4940V5) Figure 9. Output voltage vs. temperature (L4940V85) Figure 10. Output voltage vs. temperature (L4940V12) Figure 11. Quiescent current vs.
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Performance characteristics L4940 Figure 12. Quiescent current vs. input voltage (L4940V5) Figure 13. Quiescent current vs. output current (L4940V5) Figure 14. Short-circuit current vs. temperature Figure 15. Peak output current vs. input/output (L4940V5) differential voltage (L4940V5) Figure 16. Low voltage behavior (L4940V5) 10/22 Figure 17.
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L4940 Performance characteristics Figure 18. Low voltage behavior (L4940V12) Figure 19. Supply voltage rejection vs. frequency (L4940V5) Figure 20. Supply voltage rejection vs. output Figure 21. Load dump characteristics (L4940V5) current (L4940V5) Figure 22. Line transient response (L4940V5) Figure 23.
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Performance characteristics L4940 Figure 24.
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L4940 7 Application circuits Application circuits Figure 25. Distributed power supply with the L4960, L4940 and the L4941 Figure 26. Distributed power supply with the L296, L4940, and the L4941 Note: Advantages of these applications are: On-card regulation with short-circuit and thermal protection on each output. Very high total system efficiency due to the switching pre-regulation and very low drop post-regulation.
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Application circuits L4940 Figure 27. Secondary regulation for switch mode power supply with the L4940 Note: Advantages of this configuration are: Very high regulation (line and load on both the output voltage. 12 V output short-circuit and thermal protection. Very high efficiency on the 12 V output due to the low drop regulator.
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L4940 8 Package mechanical data 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. ECOPACK® is an ST trademark. Table 7. TO-220 mechanical data mm Dim. Min. Typ. Max. A 4.40 4.60 b 0.61 0.88 b1 1.14 1.70 c 0.48 0.70 D 15.25 15.75 E 10 10.40 e 2.40 2.
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Package mechanical data L4940 Figure 28.
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L4940 Package mechanical data Table 8. D²PAK mechanical data mm Dim. Min. Typ. Max. A 4.40 4.60 A1 0.03 0.23 b 0.70 0.93 b2 1.14 1.70 c 0.45 0.60 c2 1.23 1.36 D 8.95 9.35 D1 7.50 E 10 E1 8.50 10.40 e 2.54 e1 4.88 5.28 H 15 15.85 J1 2.49 2.69 L 2.29 2.79 L1 1.27 1.40 L2 1.30 1.75 R V2 0.
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Package mechanical data L4940 Figure 29. D²PAK drawings 0079457_T Figure 30. D²PAK footprint(a) 16.90 12.20 5.08 1.60 3.50 9.75 a. All dimensions are in millimeters.
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L4940 9 Packaging mechanical data Packaging mechanical data Table 9. D²PAK tape and reel mechanical data Tape Reel mm mm Dim. Dim. Min. Max. A0 10.5 10.7 A B0 15.7 15.9 B 1.5 D 1.5 1.6 C 12.8 D1 1.59 1.61 D 20.2 E 1.65 1.85 G 24.4 F 11.4 11.6 N 100 K0 4.8 5.0 T P0 3.9 4.1 P1 11.9 12.1 Base qty 1000 P2 1.9 2.1 Bulk qty 1000 R 50 T 0.25 0.35 W 23.7 24.3 DocID2141 Rev 13 Min. Max. 330 13.2 26.4 30.
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Packaging mechanical data L4940 Figure 31. Tape 10 pitches cumulative tolerance on tape +/- 0.2 mm T P0 Top cover tape P2 D E F B1 W K0 B0 For machine ref. only including draft and radii concentric around B0 A0 P1 D1 User direction of feed R Bending radius User direction of feed AM08852v1 Figure 32. Reel T REEL DIMENSIONS 40mm min. Access hole At slot location B D C N A Full radius Tape slot in core for tape start 25 mm min.
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L4940 Revision history 10 Revision history Table 10. Document revision history Date Revision 04-Feb-2005 6 Added new package D²PAK/A. 18-Sep-2006 7 Order codes and new template have been updated. 31-May-2007 8 Order codes have been updated. 19-Sep-2007 9 Added Table 1 to cover page. 20-Feb-2008 10 Modified: Table 1 on page 1. 29-Jul-2009 11 Modified: Table 1 on page 1. 16-Dec-2009 12 Modified: Table 6 on page 8.
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L4940 Please Read Carefully: Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale.