ST L78S05, L78S09, L78S12, L78S18, L78S05C User Manual

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

L78Sxx

L78SxxC

2 A positive voltage regulators

Datasheet − production data

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 shut­down 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

May 2012 Doc ID 2148 Rev 7 1/39

This is information on a product in full production.

www.st.com

39

Contents L78Sxx, L78SxxC

Contents

1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4 Test circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6 Typical performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

8 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

2/39 Doc ID 2148 Rev 7

L78Sxx, L78SxxC List of tables

List of tables

Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Table 2. Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 3. Thermal data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 4. Electrical characteristics of L78S05 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Table 5. Electrical characteristics of L78S75 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Table 6. Electrical characteristics of L78S09 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Table 7. Electrical characteristics of L78S10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 8. Electrical characteristics of L78S12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 9. Electrical characteristics of L78S15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 10. Electrical characteristics of L78S18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Table 11. Electrical characteristics of L78S24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 12. Electrical characteristics of L78S05C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 13. Electrical characteristics of L78S75C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 14. Electrical characteristics of L78S09C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Table 15. Electrical characteristics of L78S10C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 16. Electrical characteristics of L78S12C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Table 17. Electrical characteristics of L78S15C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Table 18. Electrical characteristics of L78S18C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Table 19. Electrical characteristics of L78S24C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 20. TO-220 mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 21. Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Table 22. Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Doc ID 2148 Rev 7 3/39

List of figures L78Sxx, L78SxxC

List of figures

Figure 1. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2. Pin connections (top view) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 3. Schematic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 4. Application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 5. DC parameter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 6. Load regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 7. Ripple rejection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 8. Dropout voltage vs. junction temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 9. Peak output current vs. input/output differential voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 10. Output impedance vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 11. Output voltage vs. junction temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 12. Supply voltage rejection vs. frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 13. Quiescent current vs. junction temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 14. Load transient response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 15. Line transient response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 16. Quiescent current vs. input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 17. Fixed output regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 18. Constant current regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 19. Circuit for increasing output voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 20. Adjustable output regulator (7 to 30 V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 21. 0.5 to 10 V regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 22. High current voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 23. High output current with short circuit protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Figure 24. Tracking voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 25. Positive and negative regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 26. Negative output voltage circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 27. Switching regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 28. High input voltage circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Figure 29. High input voltage circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 30. High output voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 31. High input and output voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 32. Reducing power dissipation with dropping resistor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 33. Remote shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 34. Power AM modulator (unity voltage gain, I

Figure 35. Adjustable output voltage with temperature compensation . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 36. Light controllers (V

Figure 37. Protection against input short-circuit with high capacitance loads . . . . . . . . . . . . . . . . . . . 31

Figure 38. Drawing dimension TO-220 (type STD-ST Dual Gauge) . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Figure 39. Drawing dimension TO-220 (type STD-ST Single Gauge) . . . . . . . . . . . . . . . . . . . . . . . . . 34

Figure 40. Drawing dimension tube for TO-220 Dual Gauge (mm.) . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Figure 41. Drawing dimension tube for TO-220 Single Gauge (mm.) . . . . . . . . . . . . . . . . . . . . . . . . . 35

= VXX + VBE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Omin

≤ 1 A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

O

4/39 Doc ID 2148 Rev 7

L78Sxx, L78SxxC Diagram

1 Diagram

Figure 1. Block diagram

Doc ID 2148 Rev 7 5/39

Pin configuration L78Sxx, L78SxxC

2 Pin configuration

Figure 2. Pin connections (top view)

TO-220

Figure 3. Schematic diagram

TO-3

6/39 Doc ID 2148 Rev 7

L78Sxx, L78SxxC Maximum ratings

3 Maximum ratings

Table 2. Absolute maximum ratings

Symbol Parameter Value Unit

for V

= 5 to 18V 35

O

= 24V 40

for V

O

for L78Sxx -55 to 150

for L78SxxC 0 to 150

V

°C

T

P

T

V

I

STG

OP

DC input voltage

I

Output current Internally limited

O

Power dissipation Internally limited

D

Storage temperature range -65 to 150 °C

Operating junction temperature range

Note: Absolute maximum ratings are those values beyond which damage to the device may occur.

Functional operation under these condition is not implied.

Table 3. Thermal data

Symbol Parameter TO-220 TO-3 Unit

R

thJC

R

thJA

Figure 4. Application circuits

Thermal resistance junction-case 5 4 °C/W

Thermal resistance junction-ambient 50 35 °C/W

Doc ID 2148 Rev 7 7/39

Test circuits L78Sxx, L78SxxC

4 Test circuits

Figure 5. DC parameter

Figure 6. Load regulation

Figure 7. Ripple rejection

8/39 Doc ID 2148 Rev 7

L78Sxx, L78SxxC Electrical characteristics

5 Electrical characteristics

Refer to the test circuits, TJ = 25 °C, VI = 10 V, IO = 500 mA, unless otherwise specified.

Table 4. Electrical characteristics of L78S05

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

ΔV

ΔV

ΔI

ΔV

Output voltage 4.8 5 5.2 V

O

Output voltage IO = 1 A, VI = 7 V 4.75 5 5.25 V

O

= 7 to 25 V 100

V

Line regulation

O

Load regulation IO = 20 mA to 2 A 100 mV

O

I

Quiescent current 8 mA

Q

Quiescent current change

Q

/ΔT Output voltage drift IO = 5 mA, TJ = -55 °C to 150 °C -1.1 mV/°C

O

I

VI = 8 to 25 V 50

I

= 20 mA to 1 A 0.5

O

= 7 to 25 V, IO = 20 mA 1.3

V

I

eN Output noise voltage B =10 Hz to 100 kHz 40 µV

SVR Supply voltage rejection f = 120 Hz 60 dB

V

Operating input voltage IO ≤ 1 A 8 V

I

R

I

I

Output resistance f = 1 kHz 17 mΩ

O

Short circuit current VI = 27 V 500 mA

sc

Short circuit peak current 3 A

scp

mV

mA

Doc ID 2148 Rev 7 9/39

Electrical characteristics L78Sxx, L78SxxC

Refer to the test circuits, TJ = 25 °C, VI = 12.5 V, IO = 500 mA, unless otherwise specified.

Table 5. Electrical characteristics of L78S75

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

ΔV

ΔV

ΔI

Output voltage 7.15 7.5 7.9 V

O

Output voltage IO = 1 A, VI = 9.5 V 7.1 7.5 7.95 V

O

V

= 9.5 to 25 V 120

Line regulation

O

Load regulation IO = 20 mA to 2 A 120 mV

O

I

Quiescent current 8 mA

Q

Quiescent current change

Q

I

= 10.5 to 20 V 60

V

I

I

= 20 mA to 1 A 0.5

O

= 20 mA, VI = 9.5 to 25 V 1.3

I

O

ΔVO/ΔT Output voltage drift IO = 5 mA, TJ = -55 °C to 150 °C -0.8 mV/°C

eN Output noise voltage B =10 Hz to 100 kHz 52 µV

SVR Supply voltage rejection f = 120 Hz 54 dB

V

Operating input voltage IO ≤ 1.5 A 10.5 V

I

R

I

I

Output resistance f = 1 kHz 16 mΩ

O

Short circuit current VI = 27 V 500 mA

sc

Short circuit peak current 3 A

scp

Refer to the test circuits, TJ = 25 °C, VI = 14 V, IO = 500 mA, unless otherwise specified.

Table 6. Electrical characteristics of L78S09

mV

mA

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

ΔV

ΔV

ΔI

ΔV

Output voltage 8.65 9 9.35 V

O

Output voltage IO = 1 A, VI = 11 V 8.6 9 9.4 V

O

V

= 11 to 25 V 130

Line regulation

O

Load regulation IO = 20 mA to 2 A 130 mV

O

I

Quiescent current 8 mA

Q

Quiescent current change

Q

/ΔT Output voltage drift IO = 5 mA, TJ = -55 °C to 150 °C -1 mV/°C

O

I

VI = 11 to 20 V 65

I

= 20mA to 1A 0.5

O

= 11 to 25 V, IO = 20 mA 1.3

V

I

eN Output noise voltage B =10 Hz to 100 kHz 60 µV

SVR Supply voltage rejection f = 120 Hz 53 dB

V

Operating input voltage IO ≤ 1.5 A 12 V

I

R

I

I

Output resistance f = 1 kHz 17 mΩ

O

Short circuit current VI = 27 V 500 mA

sc

Short circuit peak current 3 A

scp

10/39 Doc ID 2148 Rev 7

mV

mA

L78Sxx, L78SxxC Electrical characteristics

Refer to the test circuits, TJ = 25 °C, VI = 15 V, IO = 500 mA, unless otherwise specified.

Table 7. Electrical characteristics of L78S10

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

ΔV

ΔV

ΔI

Output voltage 9.5 10 10.5 V

O

Output voltage IO = 1 A, VI = 12.5 V 9.4 10 10.6 V

O

V

= 12.5 to 30 V 200

Line regulation

O

Load regulation IO = 20 mA to 2 A 150 mV

O

I

Quiescent current 8 mA

Q

Quiescent current change

Q

I

= 14 to 22 V 100

V

I

I

= 20 mA to 1A 0.5

O

= 12.5 to 30 V, IO = 20 mA 1

V

I

ΔVO/ΔT Output voltage drift IO = 5 mA, TJ = -55 °C to 150 °C -1 mV/°C

eN Output noise voltage B =10 Hz to 100 kHz 65 µV

SVR Supply voltage rejection f = 120 Hz 53 dB

V

Operating input voltage IO ≤ 1.5 A 13 V

I

R

I

I

Output resistance f = 1 kHz 17 mΩ

O

Short circuit current VI = 27 V 500 mA

sc

Short circuit peak current 3 A

scp

Refer to the test circuits, TJ = 25 °C, VI = 19 V, IO = 500 mA, unless otherwise specified.

Table 8. Electrical characteristics of L78S12

mV

mA

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

ΔV

ΔV

ΔI

ΔV

Output voltage 11.5 12 12.5 V

O

Output voltage IO = 1 A, VI = 14.5 V 11.4 12 12.6 V

O

V

= 14.5 to 30 V 240

Line regulation

O

Load regulation IO = 20 mA to 2 A 160 mV

O

I

Quiescent current 8 mA

Q

Quiescent current change

Q

/ΔT Output voltage drift IO = 5 mA, TJ = -55 °C to 150 °C -1 mV/°C

O

I

VI = 16 to 22 V 120

I

= 20 mA to 1 A 0.5

O

= 14.5 to 30 V, IO = 20 mA 1

V

I

mV

mA

eN Output noise voltage B =10 Hz to 100 kHz 75 µV

SVR Supply voltage rejection f = 120 Hz 53 dB

V

Operating input voltage IO ≤ 1.5 A 15 V

I

R

I

I

Output resistance f = 1 kHz 18 mΩ

O

Short circuit current VI = 27 V 500 mA

sc

Short circuit peak current 3 A

scp

Doc ID 2148 Rev 7 11/39

Electrical characteristics L78Sxx, L78SxxC

Refer to the test circuits, TJ = 25 °C, VI = 23 V, IO = 500 mA, unless otherwise specified.

Table 9. Electrical characteristics of L78S15

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

ΔV

ΔV

ΔI

Output voltage 14.4 15 15.6 V

O

Output voltage IO = 1 A, VI = 17.5 V 14.25 15 15.75 V

O

V

= 17.5 to 30 V 300

Line regulation

O

Load regulation IO = 20 mA to 2 A 180 mV

O

I

Quiescent current 8 mA

Q

Quiescent current change

Q

I

= 20 to 26 V 150

V

I

I

= 20 mA to 1 A 0.5

O

= 17.5 to 30 V, IO = 20 mA 1

V

I

ΔVO/ΔT Output voltage drift IO = 5 mA, TJ = -55 °C to 150 °C -1 mV/°C

eN Output noise voltage B =10 Hz to 100 kHz 90 µV

SVR Supply voltage rejection f = 120 Hz 52 dB

V

Operating input voltage IO ≤ 1.5 A 18 V

I

R

I

I

Output resistance f = 1 kHz 19 mΩ

O

Short circuit current VI = 27 V 500 mA

sc

Short circuit peak current 3 A

scp

Refer to the test circuits, TJ = 25 °C, VI = 26 V, IO = 500 mA, unless otherwise specified.

Table 10. Electrical characteristics of L78S18

mV

mA

Symbol Parameter Test conditions Min. Typ. Max. Unit

V

V

ΔV

ΔV

ΔI

ΔV

Output voltage 17.1 18 18.9 V

O

Output voltage IO = 1 A, VI = 20.5 V 17 18 19 V

O

V

= 20.5 to 30 V 360

Line regulation

O

Load regulation IO = 20 mA to 2 A 200 mV

O

I

Quiescent current 8 mA

Q

Quiescent current change

Q

/ΔT Output voltage drift IO = 5 mA, TJ = -55 °C to 150 °C -1 mV/°C

O

I

VI = 22 to 28 V 180

I

= 20 mA to 1 A 0.5

O

= 20.5 to 30 V, IO = 20 mA 1

V

I

eN Output noise voltage B =10 Hz to 100 kHz 110 µV

SVR Supply voltage rejection f = 120 Hz 49 dB

V

Operating input voltage IO ≤ 1.5 A 21 V

I

R

I

I

Output resistance f = 1 kHz 22 mΩ

O

Short circuit current VI = 27 V 500 mA

sc

Short circuit peak current 3 A

scp

12/39 Doc ID 2148 Rev 7

mV

mA