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. 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. If you have trouble printing, see Printing Problems . If you have trouble printing, see Printing Problems .