LM338K STMicroelectronics, LM338K Datasheet

LM338K

Manufacturer Part Number

LM338K

Description

IC VOLTAGE REG ADJ 5A TO-3

Manufacturer

STMicroelectronics

Type

Voltage Regulatorr

Datasheets

1.LM338K.pdf (23 pages)

2.LM338K.pdf (4 pages)

Specifications of LM338K

Regulator Topology

Positive Adjustable

Voltage - Output

1.2 ~ 32 V

Number Of Regulators

Current - Output

Current - Limit (min)

Operating Temperature

0°C ~ 125°C

Mounting Type

Through Hole

Package / Case

TO-204, TO-3

Polarity

Positive

Number Of Outputs

Output Type

Adjustable

Output Voltage

1.2 V to 32 V

Output Current

5 A

Line Regulation

0.03 % / V

Load Regulation

0.5 %

Input Voltage Max

35 V

Maximum Operating Temperature

+ 125 C

Minimum Operating Temperature

0 C

Mounting Style

Through Hole

Reference Voltage

1.29 V

Current, Output

3.5 mA

Current, Supply

45 μA

Package Type

TO-3

Regulation, Line

0.005 %/V

Regulation, Load

5 mV

Regulator Type

Positive Voltage Out

Resistance, Thermal, Junction To Case

1.4 °C/W

Temperature, Operating, Range

0 to +125 °C

Voltage, Noise

0.003 %

Voltage, Output

32 V

Primary Input Voltage

35V

Output Voltage Adjustable Range

1.2V To 32V

No. Of Outputs

No. Of Pins

Operating Temperature Range

0Â°C To +125Â°C

Rohs Compliant

Yes

Lead Free Status / RoHS Status

Lead free / RoHS Compliant

Voltage - Input

Voltage - Dropout (typical)

Lead Free Status / Rohs Status

Lead free / RoHS Compliant

Other names

497-2979-5

Available stocks

Company

Part Number

Manufacturer

Quantity

Price

Company:

BOSTOCK HK LIMITED

Part Number:

LM338K

Manufacturer:

Company:

BOSTOCK HK LIMITED

Part Number:

LM338K +

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Company:

BOSTOCK HK LIMITED

Part Number:

LM338K ST

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Features

■

Description

The LM138, LM238, LM338 are adjustable 3-

terminal positive voltage regulators capable of

supplying in excess of 5 A over a 1.2 V to 32 V

output range. They are exceptionally easy to use

and require only 2 resistors to set the output

voltage. Careful circuit design has resulted in

outstanding load and line regulation comparable

to many commercial power supplies. The LM138

family is supplied in a standard 3-lead transistor

package.

A unique feature of the LM138 family is time-de-

pendent current limiting. The current limit circuitry

allows peak currents of up to 12 A to be drawn

from the regulator for short periods of time. This

allows the LM138 to be used with heavy transient

loads and speeds start-up under full-load

conditions. Under sustained loading conditions,

the current limit decreases to a safe value

protecting the regulator. Also included on the chip

are thermal overload protection and safe area

protection for the power transistor. Overload

Table 1.

April 2008

Guaranteed 7 A peak output current

Guaranteed 5 A output current

Adjustable output down to 1.2 V

Line regulation typically 0.005 %/V

Load regulation typically 0.1 %

Guaranteed thermal regulation

Current limit constant with temperature

Standard 3-lead transistor package

Part numbers

Device summary

LM138

LM238

LM338

Three-terminal 5 A adjustable voltage regulators

Order codes

LM138K

LM238K

LM338K

Rev 2

protection remains functional even if the

adjustment pin is accidentally disconnected.

Normally, no capacitors are needed unless the

device is situated far from the input filter

capacitors in which case an input bypass is

needed. An optional output capacitor can be

added to improve transient response. The

adjustment terminal can be bypassed to

achieve.very high ripple rejection ratios which are

difficult to achieve with standard 3-terminal

regulators.

Besides replacing fixed regulators or discrete

designs, the LM238 is useful in a wide variety of

other applications. Since the regulator is "floating"

and sees only the input-to-output differential

voltage, supplies of several hundred volts can be

regulated as long as the maximum input to input

differential is not exceeded.

The LM138, LM238, LM338 are packaged in

standard steel TO-3 transistor package. The

LM138 is rated for operation from - 55 °C to

150 °C, the LM238 from - 25 °C to 150 °C and the

LM338 from 0 °C to 125 °C.

LM138 - LM238 - LM338

TO-3

Temperature range

-55 °C to 150 °C

-25 °C to 150 °C

0 °C to 125 °C

www.st.com

1/23

Related parts for LM338K

LM338K Summary of contents

Page 1

... TO-3 transistor package. The LM138 is rated for operation from - 55 °C to 150 °C, the LM238 from - 25 °C to 150 °C and the LM338 from 0 °C to 125 °C. Order codes LM138K LM238K LM338K Rev 2 TO-3 Temperature range -55 °C to 150 °C -25 °C to 150 °C 0 °C to 125 °C 1/23 www ...

Page 2

Contents 1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

Page 3

Diagram 1 Figure 1. Schematic diagram 3/23 ...

Page 4

Pin configuration Figure 2. Pin connections (top view) 4/23 TO-3 ...

Page 5

Maximum ratings Table 2. Absolute maximum ratings Symbol Input-output voltage differential Power dissipation D T Storage temperature range STG T Lead temperature (Soldering, 10 seconds) LEAD T Operating junction temperature range OP Note: ...

Page 6

Electrical characteristics Table 4. Electrical characteristics for LM138/LM238 Symbol Parameter (2) K Line regulation VI (2) K Load regulation VO Thermal regulation I Adjustment pin current ADJ Adjustment pin current ΔI ADJ change V Reference voltage REF (2) K ...

Page 7

Table 5. Electrical characteristics for LM338 Symbol Parameter (2) K Line regulation VI (2) K Load regulation VO Thermal regulation I Adjustment pin current ADJ Adjustment pin current ΔI ADJ change V Reference voltage REF (2) K Line regulation VI ...

Page 8

Typical characteristics Figure 3. Current limit Figure 5. Current limit 8/23 Figure 4. Current limit Figure 6. Load regulation ...

Page 9

Figure 7. Dropout voltage Figure 9. Temperature stability Figure 8. Adjustment current Figure 10. Output impedance 9/23 ...

Page 10

Figure 11. Minimum operating current Figure 13. Ripple rejection 10/23 Figure 12. Ripple rejection Figure 14. Ripple rejection ...

Page 11

Figure 15. Line transient response Figure 16. Load transient response 11/23 ...

Page 12

Typical application Figure 17. 1 adjustable regulator Needed if device is far from filter capacitors. * Optional-improves transient response. Output capacitors in the range of 1mF to 100mF of aluminium or tantalum electrolytic are commonly ...

Page 13

Application hints In operation, the LM338 develops a nominal 1.25 V reference voltage, V output and adjustment terminal. The reference voltage is impressed across program resistor R and, since the voltage is constant, a constant current I 1 resistor ...

Page 14

Although the LM338 is stable with no output capacitors, like any feedback circuit, certain values of external capacitance can cause excessive ringing. This occurs with values between 500 pF and 5000 pF ...

Page 15

Figure 19. Regulator with line resistance in output lead Figure 20. Regulator with protection diodes 15/23 ...

Page 16

Figure 21 regulator * Minimum load - 100 mA ≥ ≥ ≥ 3 Figure 22 current regulator * Minimum load - 100 ...

Page 17

Figure 23 regulator * Minimum load - 100mA ≥ ≥ ≥ 17/23 ...

Page 18

Figure 24 logic regulator with electronic shutdown = 240 Ω for LM138 or LM238 * 720 Ω for LM138 or LM238 * Minimum load - 100 mA Figure 25. Tracking pre-regulator = ...

Page 19

Figure 26. Slow turn- regulator = 240 Ω for LM138 or LM238 * 2.7 kΩ for LM138 or LM238 2 19/23 ...

Page 20

Package mechanical data In order to meet environmental requirements, ST offers these devices in ECOPACK packages. These packages have a lead-free second level interconnect. The category of second Level Interconnect is marked on the package and on the inner ...

Page 21

TO-3 mechanical data mm. Dim. Min. Typ. A 11.85 B 0.96 1. 10 30.10 Max. Min. 1.10 0.037 1.70 8.7 20.0 26.2 4.09 0.152 39 ...

Page 22

Revision history Table 6. Document revision history Date Revision 16-Apr-2003 1 11-Apr-2008 2 22/23 Changes First release. Added: Table 1 on page 1. ...

Page 23

... 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. ...

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