Datasheet

ManualsBrandsSTMICROELECTRONICS ManualsVoltage Regulators78S12 Fixed Voltage Regulator 2A, Positive

This is information on a product in full production.

May 2012 Doc ID 2148 Rev 7 1/39

L78Sxx

L78SxxC

2 A positive voltage regulators

Datasheet − production data

Features

■ Output current to 2 A

■ Output voltages of 5; 7.5; 9; 10; 12; 15; 18; 24 V

■ Thermal overload protection

■ Short circuit protection

■ Output transition SOA protection

Description

The L78Sxx series of three-terminal positive

regulators is available in TO-220 and TO-3

packages and several fixed output voltages,

making it useful in a wide range of applications.

These regulators can provide local on-card

regulation, eliminating the distribution problems

associated with single point regulation. Each type

employs internal current limiting, thermal shut-

down and safe area protection, making it

essentially indestructible. If adequate heat sinking

is provided, they can deliver over 2 A output

current. Although designed primarily as fixed

voltage regulators, these devices can be used

with external components to obtain adjustable

voltages and currents.

TO-220

TO-3

Table 1. Device summary

Part numbers

L78S05 L78S09 L78S12 L78S18

L78S05C L78S09C L78S12C L78S18C

L78S75 L78S10 L78S15 L78S24

L78S75C L78S10C L78S15C L78S24C

www.st.com

Summary of content (39 pages)

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L78Sxx L78SxxC 2 A positive voltage regulators Datasheet − production data Features ■ Output current to 2 A ■ Output voltages of 5; 7.5; 9; 10; 12; 15; 18; 24 V ■ Thermal overload protection ■ Short circuit protection ■ Output transition SOA protection Description TO-220 TO-3 The L78Sxx series of three-terminal positive regulators is available in TO-220 and TO-3 packages and several fixed output voltages, making it useful in a wide range of applications.
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Contents L78Sxx, L78SxxC Contents 1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4 Test circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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L78Sxx, L78SxxC List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Table 21. Table 22. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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List of figures L78Sxx, L78SxxC List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. Figure 39. Figure 40. Figure 41.
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L78Sxx, L78SxxC 1 Diagram Figure 1.
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Pin configuration L78Sxx, L78SxxC 2 Pin configuration Figure 2. Pin connections (top view) TO-3 TO-220 Figure 3.
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L78Sxx, L78SxxC Maximum ratings 3 Maximum ratings Table 2. Absolute maximum ratings Symbol Parameter Value for VO= 5 to 18V 35 for VO= 24V 40 VI DC input voltage IO Output current Internally limited PD Power dissipation Internally limited TSTG Storage temperature range TOP Operating junction temperature range Unit V -65 to 150 for L78Sxx °C -55 to 150 °C for L78SxxC 0 to 150 Note: Absolute maximum ratings are those values beyond which damage to the device may occur.
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Test circuits 4 Test circuits Figure 5. DC parameter Figure 6. Load regulation Figure 7.
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L78Sxx, L78SxxC 5 Electrical characteristics Electrical characteristics Refer to the test circuits, TJ = 25 °C, VI = 10 V, IO = 500 mA, unless otherwise specified. Table 4. Symbol Electrical characteristics of L78S05 Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 7 V Min. Typ. Max. Unit 4.8 5 5.2 V 4.75 5 5.
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Electrical characteristics L78Sxx, L78SxxC Refer to the test circuits, TJ = 25 °C, VI = 12.5 V, IO = 500 mA, unless otherwise specified. Table 5. Symbol Electrical characteristics of L78S75 Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 9.5 V Min. Typ. Max. Unit 7.15 7.5 7.9 V 7.1 7.5 7.95 V VI = 9.5 to 25 V 120 VI = 10.
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L78Sxx, L78SxxC Electrical characteristics Refer to the test circuits, TJ = 25 °C, VI = 15 V, IO = 500 mA, unless otherwise specified. Table 7. Symbol Electrical characteristics of L78S10 Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 12.5 V Min. Typ. Max. Unit 9.5 10 10.5 V 9.4 10 10.6 V VI = 12.
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Electrical characteristics L78Sxx, L78SxxC Refer to the test circuits, TJ = 25 °C, VI = 23 V, IO = 500 mA, unless otherwise specified. Table 9. Symbol Electrical characteristics of L78S15 Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 17.5 V Min. Typ. Max. Unit 14.4 15 15.6 V 14.25 15 15.75 V VI = 17.
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L78Sxx, L78SxxC Electrical characteristics Refer to the test circuits, TJ = 25 °C, VI = 33 V, IO = 500 mA, unless otherwise specified. Table 11. Symbol Electrical characteristics of L78S24 Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 27 V Min. Typ. Max. Unit 23 24 25 V 22.8 24 25.
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Electrical characteristics L78Sxx, L78SxxC Refer to the test circuits, TJ = 25 °C, VI = 10 V, IO = 500 mA, unless otherwise specified. Table 12. Symbol Electrical characteristics of L78S05C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 7 V Min. Typ. Max. Unit 4.8 5 5.2 V 4.75 5 5.25 V VI = 7 to 25 V 100 VI = 8 to 25 V 50 IO = 20 mA to 1.
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L78Sxx, L78SxxC Electrical characteristics Refer to the test circuits, TJ = 25 °C, VI = 12.5 V, IO = 500 mA, unless otherwise specified. Table 13. Symbol Electrical characteristics of L78S75C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 9.5 V Min. Typ. Max. Unit 7.15 7.5 7.9 V 7.1 7.5 7.95 V VI = 9.5 to 25 V 120 VI = 10.5 to 20 V 60 IO = 20 mA to 1.
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Electrical characteristics L78Sxx, L78SxxC Refer to the test circuits, TJ = 25 °C, VI = 14 V, IO = 500 mA, unless otherwise specified. Table 14. Symbol Electrical characteristics of L78S09C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 11 V Min. Typ. Max. Unit 8.65 9 9.35 V 8.6 9 9.4 V VI = 11 to 25 V 130 VI = 11 to 20 V 65 IO = 20 mA to 1.
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L78Sxx, L78SxxC Electrical characteristics Refer to the test circuits, TJ = 25 °C, VI = 15 V, IO = 500 mA, unless otherwise specified. Table 15. Symbol Electrical characteristics of L78S10C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 12.5 V Min. Typ. Max. Unit 9.5 10 10.5 V 9.4 10 10.6 V VI = 12.5 to 30 V 200 VI = 14 to 22 V 100 IO = 20 mA to 1.
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Electrical characteristics L78Sxx, L78SxxC Refer to the test circuits, TJ = 25 °C, VI = 19 V, IO = 500 mA, unless otherwise specified. Table 16. Symbol Electrical characteristics of L78S12C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 14.5 V Min. Typ. Max. Unit 11.5 12 12.5 V 11.4 12 12.6 V VI = 14.5 to 30 V 240 VI = 16 to 22 V 120 IO = 20 mA to 1.
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L78Sxx, L78SxxC Electrical characteristics Refer to the test circuits, TJ = 25 °C, VI = 23 V, IO = 500 mA, unless otherwise specified. Table 17. Symbol Electrical characteristics of L78S15C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 17.5 V Min. Typ. Max. Unit 14.4 15 15.6 V 14.25 15 15.75 V VI = 17.5 to 30 V 300 VI = 20 to 26 V 150 IO = 20 mA to 1.
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Electrical characteristics L78Sxx, L78SxxC Refer to the test circuits, TJ = 25 °C, VI = 26 V, IO = 500 mA, unless otherwise specified. Table 18. Symbol Electrical characteristics of L78S18C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 20.5 V Min. Typ. Max. Unit 17.1 18 18.9 V 17 18 19 V VI = 20.5 to 30 V 360 VI = 22 to 28 V 180 IO = 20 mA to 1.
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L78Sxx, L78SxxC Electrical characteristics Refer to the test circuits, TJ = 25 °C, VI = 33 V, IO = 500 mA, unless otherwise specified. Table 19. Symbol Electrical characteristics of L78S24C Parameter VO Output voltage VO Output voltage ΔVO Line regulation ΔVO Load regulation IQ ΔIQ ΔVO/ΔT Test conditions IO = 1 A, VI = 27 V Min. Typ. Max. Unit 23 24 25 V 22.8 24 25.2 V VI = 27 to 38 V 480 VI = 30 to 36 V 240 IO = 20 mA to 1.
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Typical performance L78Sxx, L78SxxC 6 Typical performance Figure 8. Dropout voltage vs. junction temperature Figure 9. Peak output current vs. input/output differential voltage Figure 10. Output impedance vs. frequency Figure 11. Output voltage vs. junction temperature Figure 12. Supply voltage rejection vs. frequency Figure 13. Quiescent current vs.
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L78Sxx, L78SxxC Typical performance Figure 14. Load transient response Figure 15. Line transient response Figure 16. Quiescent current vs. input voltage Figure 17. Fixed output regulator 1. To specify an output voltage, substitute voltage value for "XX". 2. Although no output capacitor is need for stability, it does improve transient response. 3. Required if regulator is locate an appreciable distance from power supply filter.
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Typical performance L78Sxx, L78SxxC Figure 18. Constant current regulator IO = VXX/R1+Id Figure 19. Circuit for increasing output voltage IR1 ≥ 5 Id VO = VXX(1+R2/R1)+IdR2 Figure 20.
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L78Sxx, L78SxxC Typical performance Figure 21. 0.5 to 10 V regulator VO=VXXR4/R1 Figure 22. High current voltage regulator VBEQ1 R1 = ______________ IREQ-(IQ1/bQ1) VBEQ1 IO = IREG + Q1 (IREG ______) R1 Figure 23.
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Typical performance L78Sxx, L78SxxC Figure 24. Tracking voltage regulator Figure 25.
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L78Sxx, L78SxxC Typical performance Figure 26. Negative output voltage circuit Figure 27. Switching regulator Figure 28.
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Typical performance L78Sxx, L78SxxC Figure 29. High input voltage circuit Figure 30. High output voltage regulator Figure 31.
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L78Sxx, L78SxxC Typical performance Figure 32. Reducing power dissipation with dropping resistor VI(min)-VXX-VDROP(max) R = ____________________ IO(max)+Id(max) Figure 33. Remote shutdown Figure 34. Power AM modulator (unity voltage gain, IO ≤ 1 A) Note: The circuit performs well up to 100 kHz.
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Typical performance L78Sxx, L78SxxC Figure 35. Adjustable output voltage with temperature compensation VO = VXX (1+R2/R1) + VBE Note: Q2 is connected as a diode in order to compensate the variation of the Q1 VBE with the temperature. C allows a slow rise time of the VO. Figure 36.
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L78Sxx, L78SxxC Typical performance Figure 37. Protection against input short-circuit with high capacitance loads 1. Application with high capacitance loads and an output voltage greater than 6 volts need an external diode (see Figure 30 on page 28) to protect the device against input short circuit. In this case the input voltage falls rapidly while the output voltage decrease slowly. The capacitance discharges by means of the BaseEmitter junction of the series pass transistor in the regulator.
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Package mechanical data 7 L78Sxx, L78SxxC 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 20. TO-220 mechanical data Type STD - ST Dual Gauge Type STD - ST Single Gauge mm. mm. Dim. Min. Typ. Max. Min. Typ. A 4.40 4.60 4.40 4.
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L78Sxx, L78SxxC Package mechanical data Figure 38. Drawing dimension TO-220 (type STD-ST Dual Gauge) 0015988_S Note: 1 Maximum resin gate protrusion: 0.5 mm. 2 Resin gate position is accepted in each of the two positions shown on the drawing, or their symmetrical.
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Package mechanical data L78Sxx, L78SxxC Figure 39.
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L78Sxx, L78SxxC Package mechanical data Figure 40. Drawing dimension tube for TO-220 Dual Gauge (mm.) Figure 41. Drawing dimension tube for TO-220 Single Gauge (mm.
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Package mechanical data L78Sxx, L78SxxC TO-3 mechanical data mm. Dim. Min. A inch. Typ. Max. Min. Typ. 11.85 B 0.96 Max. 0.466 1.05 1.10 0.037 0.041 0.043 C 1.70 0.066 D 8.7 0.342 E 20.0 0.787 G 10.9 0.429 N 16.9 0.665 P 26.2 R 3.88 1.031 4.09 U 0.152 39.5 V 1.555 30.10 1.185 A P D C O N B V E G U 0.
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L78Sxx, L78SxxC Order codes 8 Order codes Table 21.
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Revision history L78Sxx, L78SxxC 9 Revision history Table 22. Document revision history Date Revision 07-Sep-2006 2 Order codes updated. 20-Mar-2008 3 Added: Table 1 on page 1. 22-Mar-2010 4 Added: Table 20 on page 32, Figure 38 on page 33, Figure 39 on page 34, Figure 40 and Figure 41 on page 35. 08-Feb-2012 5 Added: order codes L78S05CV-DG, L78S12CV-DG and L78S15CV-DG Table 21 on page 37. 09-Mar-2012 6 Added: order codes L78S09CV-DG Table 21 on page 37.
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L78Sxx, L78SxxC 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.