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Details, datasheet, quote on part number:LM338K
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Datasheet text preview:
LM138 LM338 5-Amp Adjustable Regulators
March 1995
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 C use and require only 2 resistors to set the output voltage areful 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 A transistor package 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 tranU sient loads and speeds start-up under full-load conditions nder 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 N disconnected ormally 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 ripB ple rejection esides 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 w K suffix are packaged in a standard Steel TO-3 package hile those with a T suffix are packaged in a TO-220 plastic p aackage The LM138 is rated for b55 C s TJ s a 150 C n F d the LM338 is rated for 0 C s TJ s a 125 C
eatures
Y Y Y Y Y Y Y
Guaranteed 7A peak output current Guaranteed 5A output current Adjustable output down to 1 2V Guaranteed thermal regulation Current limit constant with temperature P a Product Enhancement tested Output is short-circuit protected
Applications
Y Y Y
Adjustable power supplies Constant current regulators Battery chargers
Connection Diagrams (See Physical Dimension section for further information)
(TO-3 STEEL) Metal Can Package (TO-220) Plastic 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
C1995 National Semiconductor Corporation
TL H 9060
RRD-B30M115 Printed in U S A
Absolute Maximum Ratings (Note 1)
p If Military Aerospace specified devices are required lease contact the National Semiconductor Sales ( Office Distributors for availability and specifications Note 4) Power Dissipation Input Output Voltage Differential Storage Temperature Internally limited
b 65 a 40V b0 3V C to a 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
b 55
C s TJ s a 150 C 0 C s TJ s a 125 C
Electrical Characteristics
Specifications with standard type face are for TJ e 25 C and those with boldface type apply over full Operating Temperature Range Unless otherwise specified VIN b VOUT e 5V and IOUT e 10 mA (Note 2) Symbol VREF VRLINE Parameter Reference Voltage Line Regulation Conditions Min 3V s (VIN b VOUT) s 35V 10 mA s IOUT s 5A P s 50W 3V s (VIN b VOUT) s 35V (Note 3) 1 19 LM138 Typ 1 24 0 005 0 02 VRLOAD Load Regulation 10 mA s IOUT s 5A (Note 3) 01 03 Thermal Regulation IADJ DIADJ D VR T ILOAD(Min) ICL Adjustment Pin Current Adjustment Pin Current Change Temperature Stability Minimum Load Current Current Limit 10 mA s IOUT s 5A 3V s (VIN b VOUT) s 35V TMIN s TJ s TMAX VIN b VOUT e 35V VIN b VOUT s 10V DC 0 5 ms Peak VIN b VOUT e 30V VN D VR DVIN RMS Output Noise % of VOUT Ripple Rejection Ratio Long-Term Stability iJC iJA Thermal Resistance Junction to Case Thermal Resistance Junction to Ambient (No Heat Sink) 10 Hz s f s 10 kHz VOUT e 10V f e 120 Hz CADJ e 0 mF VOUT e 10V f e 120 Hz CADJ e 10 mF TJ e 125 C 1000 Hrs K Package 35 60 5 7 20 ms Pulse 0 002 45 0 2 Max 1 29 0 01 0 04 03 06 0 01 100 5 V %V %V % % %W mA mA % 5 mA A A 1 A % dB dB 1 1 % Units
1 35 8 12 1 0 003 60 75 03
CW CW
K Package
2
Electrical Characteristics (Continued) Specifications with standard type face are for TJ e 25 C and those with boldface type apply over full Operating Temperature Range Unless otherwise specified VIN b VOUT e 5V and IOUT e 10 mA (Note 2)
Symbol VREF VRLINE VRLOAD Parameter Reference Voltage Line Regulation Load Regulation Thermal Regulation IADJ DIADJ D VR T ILOAD(Min) ICL Adjustment Pin Current Adjustment Pin Current Change Temperature Stability Minimum Load Current Current Limit 10 mA s IOUT s 5A 3V s (VIN b VOUT) s 35V TMIN s TJ s TMAX VIN b VOUT e 35V VIN b VOUT s 10V DC 0 5 ms Peak VIN b VOUT e 30V VN D VR DVIN RMS Output Noise % of VOUT Ripple Rejection Ratio Long-Term Stability iJC iJA Thermal Resistance Junction to Case Thermal Resistance Junction to Ambient (No Heat Sink) 10 Hz s f s 10 kHz VOUT e 10V f e 120 Hz CADJ e 0 mF VOUT e 10V f e 120 Hz CADJ e 10 mF TJ e 125 C 1000 hrs K Package T Package K Package T Package 35 50 60 0 003 60 75 03 1 1 4 5 7 Conditions Min 3V s (VIN b VOUT) s 35V 10 mA s IOUT s 5A P s 50W 3V s (VIN b VOUT) s 35V (Note 3) 10 mA s IOUT s 5A (Note 3) 20 ms Pulse 1 19 LM338 Typ 1 24 0 005 0 02 01 03 0 002 45 0 2 Max 1 29 0 03 0 06 05 1 0 02 100 5 V %V %V % % %W mA mA % 10 mA A A 1 A % dB dB % Units
1 35 8 12
C C C C
W W W W
Note 1 Absolute Maximum Ratings indicate limits beyond which damage to the device may occur Operating Ratings indicate conditions for which the device is N intended to be functional but do not guarantee specific performance limits For guaranteed specifications and test conditions see the Electrical Characteristics ote 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 t 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 N e numbers in the Min and Max columns) are guaranteed to National's AOQL (Average Outgoing Quality Level) h ote 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 N covered under the specifications for thermal regulation T te 4 Refer to RETS138K drawing for military specifications of LM138K o
ypical Performance Characteristics
Current Limit Current Limit Current Limit
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