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Figure 1. LSN2 Series Simplified Schematic

LSN2 Series

Non-isolated, DOSA-SIP, 6/10/16A

Selectable-Output DC/DC Converters

MDC_LSN2.B06 Page 5 of 15

I/O Filtering and Noise Reduction

All models in the LSN2 Series are tested and specified with external 1 || 10μF

ceramic/tantalum output capacitors and a 22μF tantalum input capacitor.

These capacitors are necessary to accommodate our test equipment and

may not be required to achieve desired performance in your application. The

LSN2's are designed with high-quality, high-performance internal I/O caps,

and will operate within spec in most applications with no additional external

components.

In particular, the LSN2's input capacitors are specified for low ESR and are

fully rated to handle the units' input ripple currents. Similarly, the internal out-

put capacitors are specified for low ESR and full-range frequency response.

TECHNICAL NOTES

In critical applications, input/output ripple/noise may be further reduced using

filtering techniques, the simplest being the installation of external I/O caps.

External input capacitors serve primarily as energy-storage devices. They

minimize high-frequency variations in input voltage (usually caused by IR

drops in conductors leading to the DC/DC) as the switching converter draws

pulses of current. Input capacitors should be selected for bulk capacitance

(at appropriate frequencies), low ESR, and high rms-ripple-current ratings.

The switching nature of modern DC/DCs requires that the dc input voltage

source have low ac impedance at the frequencies of interest. Highly inductive

source impedances can greatly affect system stability. Your specific system

configuration may necessitate additional considerations.

Typical topology is shown