LM105/LM305/LM305A Voltage Regulators General Description The LM105 series are positive voltage regulators similar to the LM100, except that an extra gain stage has been added for improved regulation. A redesign of the biasing circuitry removes any minimum load current requirement and at the same time reduces standby current drain, permitting higher voltage operation. They are direct, plug-in replacements for the LM100 in both linear and switching regulator circuits with output voltages greater than 4.5V. Important characteristics of the circuits are: • Output voltage adjustable from 4.5V to 40V • Output currents in excess of 10A possible by adding external transistors • Load regulation better than 0.1%, full load with current limiting • DC line regulation guaranteed at 0.03%/V • Ripple rejection on 0.01%V • 45 mA output current without external pass transistor (LM305A) Like the LM100, they also feature fast response to both load and line transients, freedom from oscillations with varying resistive and reactive loads and the ability to start reliably on any load within rating. The circuits are built on a single silicon chip and are supplied in a TO-99 metal can. The LM105 is specified for operation for −55°C £ TA £ +125°C, and the LM305/LM305A is specified for 0°C £ TA £ +70°C.