LM3411 Precision Secondary Regulator/Driver
December 1999
LM3411 Precision Secondary Regulator/Driver
General Descript...
LM3411 Precision Secondary
Regulator/Driver
December 1999
LM3411 Precision Secondary
Regulator/Driver
General Description
The LM3411 is a low power fixed-voltage (3.3V or 5.0V) precision shunt
regulator designed specifically for driving an optoisolator to provide feedback isolation in a switching
regulator. The LM3411 circuitry includes an internally compensated op amp, a bandgap reference,
NPN output
transistor, and voltage setting resistors. A trimmed precision bandgap reference with temperature drift curvature correction, provides a guaranteed 1% precision over the operating temperature range (A grade version). The amplifier’s inverting input is externally accessible for loop frequency compensation when used as part of a larger servo system. The output is an open-emitter
NPN transistor capable of driving up to 15 mA of load current. Because of its small die size, the LM3411 has been made available in the sub-miniature 5-lead SOT23-5 surface mount package. This package is ideal for use in space critical applications. Although its main application is to provide a precision output voltage (no trimming required) and maintain very good regulation in isolated DC/DC converters, it can also be used with other types of voltage
regulators or power semiconductors to provide a precision output voltage without precision resistors or trimming.
Features
n Fixed voltages of 3.3V and 5.0V with initial tolerance of ± 1% for standard grade and ± 0.5% for A grade n Custom voltages availabl...