Coupling
Circuit
PLT-22
Txcvr
Neuron
Chip
Power
Mains
Switching
Power
Supply
330ž ±5% 1/4W
3.3ž ±5%, 1/2W,
wire wound or carbon
composition
0.015µF ±10%
0.47µF ±20%
X2 Type
250VAC
100µH ±20%
100µH ±10%
Figure 5.9
Optional Switching Power Supply LC Network
This filter has the attenuation characteristics shown in figure 5.10, when
connected to a 50
Ω
mains network. If the supply noise drops by less than the
values shown in figure 5.10 it is likely due to parasitic coupling between the two
inductors. If this occurs, filtering close to the level shown in figure 5.10 can
usually be accomplished by adjusting the relative location and orientation of the
inductors (orthogonal orientation typically reduces inductor coupling). Alternately,
shielded or toroidal inductors may be used to reduce coupling.
Frequency (Hz)
Attenuation (dB)
Communication
frequencies
(110 - 140kHz)
Figure 5.10
Filter Frequency Response
5-16
Power Supplies for the PLT-22 Transceiver
Summary of Contents for LONWORKS PLT-22
Page 6: ...iv Echelon...
Page 14: ...1 8 Introduction...
Page 67: ...LONWORKS PLT 22 Transceiver s User Guide 5 7 Figure 5 3 Capacitor Input Power Supply Schematic...
Page 92: ...6 10 Design and Test for Electromagnetic Compatibility...
Page 110: ...7 18 Communication Performance Verification...
Page 114: ...8 4 References...
Page 118: ...A 4 Appendix A...
