SNLA224B June 2014 – October 2025 DS90UB913A-Q1 , DS90UB954-Q1 , DS90UB960-Q1 , DS90UB9702-Q1
- 1
- Abstract
- Trademarks
- 1Introduction
- 2Theory of Operation for Power Over Coax
- 3Design Considerations
- 4FPD-Link PoC Requirements
- 5PoC Noise
-
6TI Reviewed PoC Networks
- 6.1 PoC Network from FPD-Link III Data Sheet
- 6.2 Murata FPD3 Networks
- 6.3 TDK FPD3 Networks
- 6.4 Coilcraft FPD3 Networks
- 6.5
Murata FPD4 Networks
- 6.5.1 Design 1
- 6.5.2 Design 2
- 6.5.3 Design 3
- 6.5.4 Design 4
- 6.5.5 Design 5
- 6.5.6 Design 6
- 6.5.7 Design 7
- 6.5.8 Design 8
- 6.5.9 Design 9
- 6.5.10 Design 10
- 6.5.11 Design 11
- 6.5.12 Design 12
- 6.5.13 Design 13
- 6.5.14 Design 14
- 6.5.15 Design 15
- 6.5.16 Design 16
- 6.5.17 Design 17
- 6.5.18 Design 18
- 6.5.19 Design 19
- 6.5.20 Design 20
- 6.5.21 Design 21
- 6.5.22 Design 22
- 6.5.23 Design 23
- 6.5.24 Design 24
- 6.5.25 Design 25
- 6.5.26 Design 26
- 6.5.27 Design 27
- 6.5.28 Design 28
- 6.5.29 Design 29
- 6.6
TDK FPD4 Networks
- 6.6.1 Design 1
- 6.6.2 Design 2
- 6.6.3 Design 3
- 6.6.4 Design 4
- 6.6.5 Design 5
- 6.6.6 Design 6
- 6.6.7 Design 7
- 6.6.8 Design 8
- 6.6.9 Design 9
- 6.6.10 Design 10
- 6.6.11 Design 11
- 6.6.12 Design 12
- 6.6.13 Design 13
- 6.6.14 Design 14
- 6.6.15 Design 15
- 6.6.16 Design 16
- 6.6.17 Design 17
- 6.6.18 Design 18
- 6.6.19 Design 19
- 6.6.20 Design 20
- 6.6.21 Design 21
- 6.6.22 Design 22
- 6.6.23 Design 23
- 6.7 Coilcraft FPD4 Networks
- 7Summary
- 8References
- 9Revision History
2.3 Inductors versus Ferrite Beads
As the frequency of FPD-Link communications rise, the need for more complex PoC networks follows. Ferrite beads can help greatly when dealing with extremely high frequencies. Ferrite beads are considered a special kind of inductor that has a very low inductance but are rated for frequencies in the MHz to GHZ range. Where standard coil inductors typically begin behaving like a capacitor, a ferrite bead continues to provide high impedance. Figure 2-8 shows a real world ferrite bead that has an inductive component, capacitive component, and resistive components. The Ferrite bead is primarily inductive, therefore LFB is the most dominant portion of this model. The parasitic capacitance CPar does not become significant until very high frequencies.
Figure 2-8 Real World Ferrite BeadAdding ferrite beads to the PoC network can result in broader frequency coverage. However, a ferrite bead can have a higher resistive component at DC than a standard coil inductor. While the resistance is typically rather small (<1?), higher DC resistance can result in significant IR drop in applications where current is drawn.