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Details, datasheet, quote on part number:LM338T
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| Part: | LM338T |
| Category: | Power Management => Regulators => Linear Voltage Regulators => Positive => Adjustable |
| Description: | LM338 - 5 Amp Adjustable Regulator, Package: TO-3, Pin Nb=3 |
| Company: | National Semiconductor Corporation |
| Datasheet: | Download LM338T datasheet File size : 406 kB |
| Request For quote: | Find where to buy LM338T
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Datasheet text preview:
LM138/LM338 5-Amp Adjustable Regulators
May 1998
LM138/LM338 5-Amp Adjustable Regulators
General Description
The LM138 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 5A over a 1.2V to 32V 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-dependent current limiting. The current limit circuitry allows peak currents of up to 12A 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 protection remains functional even if the adjustment pin is accidentally disconnected. Normally, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors in which case an input bypass is needed. An output capacitor can be added to improve transient response, while bypassing the adjustment pin will increase the regulator's ripple rejection. Besides replacing fixed regulators or discrete designs, the LM138 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 output differential is not exceeded, i.e., do not short-circuit output to ground. The part numbers in the LM138 series which have a K suffix are packaged in a standard Steel TO-3 package, while those with a T suffix are packaged in a TO-220 plastic package. The LM138 is rated for -55°C TJ +150°C, and the LM338 is rated for 0°C TJ +125°C.
Features
n n n n n n n Guaranteed 7A peak output current Guaranteed 5A output current Adjustable output down to 1.2V Guaranteed thermal regulation Current limit constant with temperature P+ Product Enhancement tested Output is short-circuit protected
Applications
n Adjustable power supplies n Constant current regulators n Battery chargers
Connection Diagrams
(See Physical Dimension section for further information) (TO-220) Plastic Package
(TO-3 STEEL) Metal Can Package
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Front View Order Number LM338T See NS Package Number T03B
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Bottom View Order Number LM138K STEEL or LM338K STEEL See NS Package Number K02A
© 1999 National Semiconductor Corporation
DS009060
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Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. (Note 4) Power Dissipation Input/Output Voltage Differential Storage Temperature Internally limited +40V, -0.3V -65°C to +150°C
Lead Temperature Metal Package (Soldering, 10 seconds) Plastic Package (Soldering, 4 seconds) ESD Tolerance
300°C 260°C TBD
Operating Temperature Range
LM138 LM338 -55°C TJ +150°C 0°C TJ +125°C
Electrical Characteristics
Specifications with standard type face are for TJ = 25°C, and those with boldface type apply over full Operating Temperature Range. Unless otherwise specified, VIN - VOUT = 5V; and IOUT = 10 mA. (Note 2) Symbol VREF VRLINE VRLOAD Parameter Reference Voltage Line Regulation Load Regulation Thermal Regulation IADJ IADJ VR/T ILOAD(Min) ICL Adjustment Pin Current Adjustment Pin Current Change Temperature Stability Minimum Load Current Current Limit 10 mA IOUT 5A, 3V (VIN - VOUT) 35V TMIN TJ TMAX VIN - VOUT = 35V VIN - VOUT 10V DC 0.5 ms Peak VIN - VOUT = 30V VN RMS Output Noise, % of VOUT Ripple Rejection Ratio Long-Term Stability JC JA Thermal Resistance, Junction to Case Thermal Resistance, Junction to Ambient (No Heat Sink) K Package 35 °C/W 10 Hz f 10 kHz VOUT = 10V, f = 120 Hz, CADJ = 0 µF VOUT = 10V, f = 120 Hz, CADJ = 10 µF TJ = 125°C, 1000 Hrs K Package 60 5 7 8 12 1 0.003 60 75 0.3 1 1 1 A A A % dB dB % °C/W 1 3.5 5 % mA Conditions Min 3V (VIN - VOUT) 35V, 10 mA IOUT 5A, P 50W 3V (VIN - VOUT) 35V (Note 3) 10 mA IOUT 5A (Note 3) 20 ms Pulse 0.005 0.02 0.1 0.3 0.002 45 0.2 0.01 0.04 0.3 0.6 0.01 100 5 %/V %/V % % %/W µA µA 1.19 LM138 Typ 1.24 Max 1.29 V Units
Electrical Characteristics
Symbol VREF VRLINE VRLOAD Parameter Reference Voltage Line Regulation Load Regulation Thermal Regulation IADJ IADJ Adjustment Pin Current Adjustment Pin Current Change 10 mA IOUT 5A, 3V (VIN - VOUT) 35V
2
Conditions Min 3V (VIN - VOUT) 35V, 10 mA IOUT 5A, P 50W 3V (VIN - VOUT) 35V (Note 3) 10 mA IOUT 5A (Note 3) 20 ms Pulse 1.19
LM338 Typ 1.24 0.005 0.02 0.1 0.3 0.002 45 0.2 Max 1.29 0.03 0.06 0.5 1 0.02 100 5
Units V %/V %/V % % %/W µA µA
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Electrical Characteristics
Symbol VR/T ILOAD(Min) ICL Parameter Temperature Stability Minimum Load Current Current Limit
(Continued) Conditions Min TMIN TJ TMAX VIN - VOUT = 35V VIN - VOUT 10V DC 0.5 ms Peak VIN - VOUT = 30V 5 7 8 12 1 0.003 60 60 75 0.3 1 1 4 35 50 A A A % dB dB % °C/W °C/W °C/W °C/W LM338 Typ 1 3.5 10 Max % mA Units
VN
RMS Output Noise, % of VOUT Ripple Rejection Ratio Long-Term Stability
10 Hz f 10 kHz VOUT = 10V, f = 120 Hz, CADJ = 0 µF VOUT = 10V, f = 120 Hz, CADJ = 10 µF TJ = 125°C, 1000 hrs K Package T Package K Package T Package
JC JA
Thermal Resistance Junction to Case Thermal Resistance, Junction to Ambient (No Heat Sink)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2: These specifications are applicable for power dissipations up to 50W for the TO-3 (K) package and 25W for the TO-220 (T) package. Power dissipation is guaranteed at these values up to 15V input-output differential. Above 15V differential, power dissipation will be limited by internal protection circuitry. All limits (i.e., the numbers in the Min. and Max. columns) are guaranteed to National's AOQL (Average Outgoing Quality Level). Note 3: Regulation is measured at a constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are covered under the specifications for thermal regulation. Note 4: Refer to RETS138K drawing for military specifications of LM138K.
Typical Performance Characteristics
Current Limit Current Limit Current Limit
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Load Regulation
Dropout Voltage
Adjustment Current
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DS009060-36 DS009060-37
3
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