LM138K

The LM138K is a product of The LM138 subseries.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.

Features of the LM138K are:(1)Guaranteed 7A peak output current;(2)Guaranteed 5A output current;(3)Adjustable output down to 1.2V;(4)Guaranteed thermal regulation;(5)Current limit constant with temperature;(6)P+ Product Enhancement tested;(7)Output is short-circuit protected.

The absolute maximum ratings of the LM138K can be summarized as:(1)Power Dissipation:Internally limited;(2)Input/Output Voltage Differential:+40V, -0.3V;(3)Storage Temperature:-65°C to +150°C;(4)Lead Temperature Metal Package (Soldering, 10 seconds):300°C;(5)Lead Temperature Plastic Package (Soldering, 4 seconds):260°C;(6)ESD Tolerance:TBD.