전자파 연구실 1 9. Connectors. 전자파 연구실 2 Primary electrical factors affecting high-speed performance in connectors Mutual inductance – cause crosstalk Series.

Presentation on theme: "전자파 연구실 1 9. Connectors. 전자파 연구실 2 Primary electrical factors affecting high-speed performance in connectors Mutual inductance – cause crosstalk Series."— Presentation transcript:

1 전자파 연구실 1 9. Connectors

2 전자파 연구실 2 Primary electrical factors affecting high-speed performance in connectors Mutual inductance – cause crosstalk Series inductance – slows down signal propagation and creates EMI Parasitic capacitance – slows down signal propagation

3 전자파 연구실 3 9.1 Mutual inductance-how connectors create crosstalk

4 전자파 연구실 4 Derivation of mutual inductance of connector pins Diameter : D Current H

5 전자파 연구실 5 9.1.1 Estimating crosstalk Mutual inductance between two loops The maximum rate of change of the source signal current dI/dt The impedance of receiving network and whether it is source or end terminated.

6 전자파 연구실 6

7 7

8 8 9.1.2 How ground alter the return-current path

9 전자파 연구실 9

10 10 9. 2 Series inductance - How connectors create EMI

11 전자파 연구실 11

12 전자파 연구실 12 Example 9.1 Noise radiated from a connector

13 전자파 연구실 13

14 전자파 연구실 14 How to reduce connector emissions

15 전자파 연구실 15 9.3 Parasitic capacitance : 9.3 Parasitic capacitance : using connectors on a multidrop bus

16 전자파 연구실 16RS-485 Characteristics of RS232, RS422, RS423 and RS485 RS232RS423RS422RS485 Differentialno yes Max number of drivers Max number of receivers1 1 10 32 Modes of operation half duplex full duplex half duplex Network topologypoint-to-pointmultidrop multipoint Max distance (acc. standard)15 m1200 m Max speed at 12 m Max speed at 1200 m 20 kbs (1 kbs) 100 kbs 1 kbs 10 Mbs 100 kbs 35 Mbs 100 kbs Max slew rate30 V/μsadjustablen/a Receiver input resistance3~7 kΩ ≧ 4 kΩ ≧ 12 kΩ Driver load impedance3~7 kΩ ≧ 450 Ω 100 Ω54 Ω Receiver input sensitivity±3 V±200 mV Receiver input range±15 V±12 V±10 V – 7~12 V Max driver output voltage±25 V±6 V – 7~12 V Min driver output voltage (with load)±5 V±3.6 V±2.0 V±1.5 V Network topology with RS485

17 전자파 연구실 17 9.4 Measuring coupling in a connector Logic gate 의 출력 임피던스를 흉내냄.

18 전자파 연구실 18 9.5 Continuity of ground underneath a connector

19 전자파 연구실 19

20 전자파 연구실 20 9.6 Fixing EMI problems with external connections Filtered output

21 전자파 연구실 21 Shielding

22 전자파 연구실 22 Common mode choke

23 전자파 연구실 23 9.7 Special connectors for high-speed applications Thin metal plate : low inductance return current carrier Very low crosstalk Z0=50Ω

24 전자파 연구실 24

25 전자파 연구실 25

26 전자파 연구실 26 9.8 Differential signaling through a connector