CC/CV Charging characteristics

Specifies the constant current to constant voltage characteristic of a converter. The voltage is controlled constantly in the nominal load range, however in the overload range the current is controlled constantly. This behavior is used in battery charging applications.



Naming of Demke DC-DC-Converter. The DC-Transformer itself simply transforms one voltage into another and provides a variable current to transmit power. A Demke DC-Transformer includes all the relevant components like control unit, power switches and EMI-filters to provide a good power of highest quality.



The energy conversion efficiency describes the ratio of output power against input power. This value is given by physical constraints smaller than 1. The conversion efficiency specified by Demke Electronic is measured at the terminals of a converter.


Efficiency at full loads

Ratio of the output power, compared to the input power at the nominal output current.


Efficiency at light loads

Ratio of the output power, compared to the input power at 10% of the nominal output current.


Efficiency at medium loads

Ratio of the output power, compared to the input power at 50% of the nominal output current.


Forward converter

All DC-DC-Converters of our 400-series are highly integrated and are on the highest technological level. These converters are single-phase forward converters with an active clamp reset. Hence, we are able to realize smallest dimensions with highest efficiency.


Generated AC-ripple on the supply (BW=20MHz)

AC component at switching frequency superimposed on the input voltage. Measuered in Millivolt (mV) Peak to Peak with a Bandwidth Limitation at 20 MHz.



Statistical mean time to failure. The probability of a failure is calculated as Px(t) = 1-e{-t/MTTF}



The Output voltage is increased slowly. This lowers the Inrush currend and prevents unintentional tripping of input fuses.


Switching frequency

Working frequency of the power supply. This switching frequency generates an alternating voltage across the internal inductors.


buck converter

A buck converter (step down converter) converts the input voltage Vin from a higher voltage level into a lower output voltage Vout.


buck-boost converter/ step up and step down converter

These converters are able to convert an input voltage Vin to a higher or lower output voltage Vout (also well-known as step up and step down converter).


heatsinking (metal case)

During operation of the DC/DC converter, the generated heatloss is dissipated via the metal housing to the ambient.


no load input current

The typical input current of the converter without connected load. Measured at the nominal input voltage.



The positive input and output voltage are both referenced to the same potential.


output current

typical maximum output current of the DC/DC converter under normal operating conditions


passive loads

purely resistive load


short circuit proof

Short-circuit-proof converters adjust the output current to a safe short-circuit current in case of overload or short circuit.


thermal shutdown

If the temperature inside the DC-DC converter exceeds the thermal shutdown threshold, the converter is deactivated. The converter is automatically switched on again as soon as the temperature has fallen below the hysteresis of the switch-off threshold.