NMG Series
Isolated 2W Single Output DC/DC Converters
KDC_NMG.E02 Page 4 of 7
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APPLICATION NOTES
Minimum load
The minimum load to meet datasheet specification is 10% of the full rated load across the specified input voltage range. Lower than 10% minimum loading will result in
an increase in output voltage, which may rise to typically double the specified output voltage if the output load falls to less than 5%.
Capacitive loading and start up
Typical start up times for this series, with a typical input voltage rise time of 2.2μs and output capacitance of 10μF, are shown in the table below. The product
series will start into a capacitance of 47μF with an increased start time, however, the maximum recommended output capacitance is 10μF.
Ripple & Noise Characterisation Method
All measurement to be taken with the following components connected to the UUT as detailed below. 50 Ohm coax cable, solder connections one end, BNC plug at
the other end.
C1
1μF X7R multilayer ceramic capacitor rated at minimum 3 x the output voltage of the UUT
C2
10μF tantalum capacitor rated at minimum 1.5 x the output voltage of the UUT with ESR of less than 100 milliohms at 100 kHz e.g. AVX TPS
series.
C3
100nF multilayer ceramic capacitor, general purpose
R1
450 Ohm resistor, carbon film, ±1%
R2
50 Ohm BNC termination
T1
3T of the coax cable through a ferrite toroid eg Ferroxcube TN32/19/13-3E25
RLOAD
Resistive load at the UUT maximum rating. Connections via twisted wires.
Measured values are multiplied by 10 to obtain the specified values.
Differential Mode Noise Test Schematic
Typical Start-Up Wave Form
Start-up time Start-up time
μs μs
NMG0505SC 444 NMG1505SC 100
NMG0509SC 1120 NMG1509SC 170
NMG0512SC 1930 NMG1512SC 300
NMG0515SC 3470 NMG1515SC 450
NMG1205SC 409 NMG2405SC 80
NMG1209SC 1320 NMG2409SC 130
NMG1212SC 1320 NMG2412SC 220
NMG1215SC 2270 NMG2415SC 330
NMG0524SC 2200
NMG1224SC 1400
OSCILLOSCOPE
Y INPUT
SUPPLY
C1 C2 C3 R1 T1
R2
Input Output
DC/DC Converter
R LOAD
+
+
-
-
