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 ensured 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.

• Fixed Voltages of 3.3V and 5.0V with Initial Tolerance of ±1% for Standard Grade and ±0.5% for A Grade
• Custom Voltages Available (3V–17V)
• Wide Output Current Range, 20 μA–15 mA
• Low Temperature Coefficient
• Available in 5-Lead SOT23-5 Surface Mount Package (Tape and Reel)