MICROCIRCUIT DATA SHEET Original Creation Date: 07/12/95 Last Update Date: 08/13/01 Last Major Revision Date: 08/02/01 MNLM138-X REV 1A0 5 AMP ADJUSTABLE POWER REGULATOR 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 condition. 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. Normanlly, 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 LM 138 is usefull 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 voltage, is not exceeded. Industry Part Number NS Part Numbers LM138 LM138K-MIL Prime Die LM138 Processing Subgrp Description MIL-STD-883, Method 5004 1 2 3 4 5 6 7 8A 8B 9 10 11 Quality Conformance Inspection MIL-STD-883, Method 5005 1 Static tests at Static tests at Static tests at Dynamic tests at Dynamic tests at Dynamic tests at Functional tests at Functional tests at Functional tests at Switching tests at Switching tests at Switching tests at Temp ( oC) +25 +125 -55 +25 +125 -55 +25 +125 -55 +25 +125 -55 MICROCIRCUIT DATA SHEET MNLM138-X REV 1A0 (Absolute Maximum Ratings) (Note 1) Power Dissipation Internally limited Storage Temperature -65 C to +150 C Lead Temperature (Soldering, 10 Sec.) Maximum Juction Temperature 300 C 150 C Input/Output Differential +40V, -0.3V Thermal Resistance ThetaJA Still Air 500LF/Min Air Flow 40 C TBD ThetaJC Package Weight (Typical) TBD TBD ESD Tolerance (Note 3) TBD Note 1: Note 2: Note 3: Absolute Maximum Rating indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test condtions. The maximum power dissipation must be derated at elevated temperatures and is dictated by Tjmax (maximum junction temperature), ThetaJA (package junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is Pdmax = (Tjmax - TA)/ThetaJA or the number given in the Absolute Maximum Ratings, whichever is lower. Human body model, 1.5K ohms in series with 100pF 2 MICROCIRCUIT DATA SHEET MNLM138-X REV 1A0 Electrical Characteristics DC PARAMETERS (The following conditions apply to all the following parameters, unless otherwise specified.) DC: Vdiff=5V, Il=10mA SYMBOL Rline Rload Vrth Iadj PARAMETER Line Regulation Load Regulation CONDITIONS NOTES 1 3.3V < Vdiff < 35V -14 14 mV 2, 3 Vdiff=3V, 10mA < Il < 5A, Vout=Vref -3.8 3.8 mV 1 Vdiff=3.3V, 10mA < Il < 5A, Vout=Vref -8 8 mV 2, 3 Vdiff=35V, 10mA < Il < 150mA, Vout=Vref -3.8 3.8 mV 1 -8 8 mV 2, 3 Adjustment Pin Current Vdiff=3V 1 0.01 %/Wat 1 2 100 t uA 2 100 uA 1, 2, 3 -5 5 uA 1, 2, 3 -5 5 uA 1, 2, 3 0.5 5 mA 1, 2, 3 0.5 5 mA 1, 2, 3 1.19 1.29 V 1, 2, 3 Vdiff=3V, Il=5A 1.19 1.29 V 1, 2, 3 Vdiff=5V, Il=7A 1.19 1.29 V 1, 2, 3 Vdiff=35V 1.19 1.29 V 1, 2, 3 Vdiff=35V, Il=150mA 1.19 1.29 V 1, 2, 3 Vdiff=10V, T=0.5mS, Vout=0V 7 16 A 1, 2, 3 T=5.0mS, Vout=0V 5 15 A 1, 2, 3 2 3V