电子说
随着车载技术的发展,需要更快地传送大量数据,车载网络的高速化变得越来越重要。车载以太网与以往的车载网络相比,有很多优点,如:最适合希望数据传输速度高速化的用途和网络,容易简化。另外,随着车载网络通信速度的提高,信号质量和EMC对策变得很重要,因此需要选择符合OPEN Alliance等标准的共模滤波器/扼流圈。本篇文章介绍了TDK用于车载以太网的ACT1210L系列共模滤波器/扼流圈。
目录
车载以太网
S参数的比较
辐射EMI的比较
传导EMI的比较
BCI的结果比较
支持TDK车载以太网的共模滤波器/扼流圈
总结
车载以太网
OPEN(One-Pair Ether-Net)Alliance Special Interest Group(SIG)推荐100BASE-T1及1000BASE-T1标准的车载以太网。本文介绍了使用符合OPEN Alliance的100BASE-T1标准的ACT1210L-201和不符合标准的ACT1210-110的共模滤波器/扼流圈的辐射EMI、传导EMI、BCI的结果。
S参数的比较
作为一个例子,图1对CAN-BUS用共模滤波器/扼流圈:ACT1210-110和车载以太网用共模滤波器/扼流圈:ACT1210L-201进行了比较。
与车载以太网用共模滤波器/扼流圈:ACT1210L-201比较,可以看到,CAN-BUS用共模滤波器/扼流圈:ACT1210-110不能满足OPEN Alliance的标准值。
图1
辐射EMI的比较
使用共模滤波器/扼流圈,可以获得抑制噪声的效果。特别是,还能获得使30MHz以上超过标准线的部分衰减到噪声基底附近的效果。(图2)车载以太网用共模滤波器/扼流圈:ACT1210L-201在10MHz~40MHz附近,与CAN-BUS用共模滤波器/扼流圈:ACT1210-110比较,可以获得噪声抑制效果更好的结果。
Emission Test for 100BASE-T1 (Automotive Ethernet)
图2
Setup
Status
・Class: CISPR25 Ed3 class 5
・Test site: Anechoic chamber (3m)
・DUT: 100BASE-T1 EVB
・Cable length: 1.5 m
传导EMI的比较
使用共模滤波器/扼流圈,可以获得抑制噪声的效果。特别是在40MHz~90MHz超过标准的部分也能抑制噪声。(图3)
在150kHz~70MHz的范围内,车载以太网用共模滤波器/扼流圈:ACT1210L-201更能发挥噪声抑制效果。
图3
Setup
Status
・Class: CISPR25 Ed3 class 5
・Test site: Anechoic chamber (3m)
・DUT: 100BASE-T1 EVB
・Cable length: 1.5 m
Comparison of BCI Results
Through时,几乎在所有的频率都会Fail,但加入共模滤波器/扼流圈后可以大幅改善。
车载以太网用共模滤波器/扼流圈:ACT1210L-201全部Pass。(表1)
Setup
Status
・Frequency: 1 - 400 MHz (CW)
・Injection Current: 200 mA (closed-loop method)
・Decision: CRC Error
・Test site: Shield room
Table 1
Frequency MHz | Through | ACT1210-110 | ACT1210L-201 |
---|---|---|---|
1.00 | Fail | Fail | Pass |
1.20 | Fail | Fail | Pass |
1.44 | Fail | Fail | Pass |
1.73 | Fail | Fail | Pass |
2.07 | Fail | Fail | Pass |
2.49 | Fail | Fail | Pass |
2.99 | Fail | Fail | Pass |
3.58 | Fail | Fail | Pass |
4.30 | Fail | Fail | Pass |
5.16 | Fail | Fail | Pass |
6.19 | Fail | Fail | Pass |
7.43 | Fail | Fail | Pass |
8.92 | Fail | Fail | Pass |
10.70 | Fail | Fail | Pass |
12.84 | Fail | Fail | Pass |
15.41 | Fail | Fail | Pass |
18.49 | Fail | Fail | Pass |
20.00 | Fail | Fail | Pass |
21.00 | Fail | Pass | Pass |
22.05 | Fail | Pass | Pass |
23.15 | Fail | Pass | Pass |
24.31 | Fail | Pass | Pass |
25.53 | Fail | Pass | Pass |
26.80 | Fail | Pass | Pass |
27.00 | Fail | Pass | Pass |
28.14 | Fail | Pass | Pass |
29.55 | Pass | Pass | Pass |
31.03 | Fail | Pass | Pass |
32.58 | Fail | Pass | Pass |
34.21 | Fail | Pass | Pass |
Frequency MHz | Through | ACT1210-110 | ACT1210L-201 |
---|---|---|---|
35.92 | Fail | Pass | Pass |
37.71 | Fail | Pass | Pass |
39.60 | Fail | Pass | Pass |
41.58 | Fail | Pass | Pass |
43.66 | Fail | Pass | Pass |
45.00 | Fail | Pass | Pass |
45.84 | Fail | Pass | Pass |
48.13 | Fail | Pass | Pass |
50.54 | Fail | Fail | Pass |
53.07 | Fail | Fail | Pass |
55.72 | Fail | Pass | Pass |
58.51 | Fail | Fail | Pass |
61.43 | Fail | Pass | Pass |
64.50 | Fail | Pass | Pass |
67.73 | Fail | Pass | Pass |
69.81 | Fail | Pass | Pass |
71.11 | Fail | Pass | Pass |
74.67 | Fail | Pass | Pass |
78.40 | Fail | Pass | Pass |
82.32 | Fail | Pass | Pass |
86.44 | Fail | Pass | Pass |
90.00 | Fail | Pass | Pass |
90.76 | Fail | Pass | Pass |
95.30 | Fail | Pass | Pass |
100.06 | Fail | Pass | Pass |
105.07 | Fail | Pass | Pass |
110.32 | Fail | Pass | Pass |
115.84 | Fail | Pass | Pass |
120.00 | Fail | Pass | Pass |
121.63 | Fail | Pass | Pass |
Frequency MHz | Through | ACT1210-110 | ACT1210L-201 |
---|---|---|---|
127.71 | Fail | Pass | Pass |
134.10 | Fail | Pass | Pass |
140.80 | Fail | Pass | Pass |
147.84 | Fail | Pass | Pass |
155.23 | Fail | Pass | Pass |
162.99 | Fail | Pass | Pass |
171.14 | Fail | Pass | Pass |
179.70 | Fail | Pass | Pass |
188.69 | Fail | Pass | Pass |
190.00 | Fail | Pass | Pass |
198.12 | Fail | Pass | Pass |
198.12 | Fail | Pass | Pass |
208.03 | Fail | Pass | Pass |
218.43 | Fail | Pass | Pass |
229.35 | Fail | Pass | Pass |
240.82 | Fail | Pass | Pass |
252.86 | Fail | Pass | Pass |
265.50 | Fail | Pass | Pass |
278.77 | Fail | Pass | Pass |
280.00 | Fail | Pass | Pass |
292.71 | Fail | Pass | Pass |
307.35 | Fail | Pass | Pass |
322.72 | Fail | Pass | Pass |
338.85 | Fail | Pass | Pass |
355.79 | Fail | Pass | Pass |
373.58 | Fail | Pass | Pass |
380.00 | Fail | Pass | Pass |
392.26 | Fail | Pass | Pass |
400.00 | Pass | Pass | Pass |
支持TDK车载以太网的共模滤波器/扼流圈
作为支持车载以太网的共模滤波器/扼流圈,TDK准备了符合OPEN Alliance标准的100BASE-T1及1000BASE-T1用共模滤波器/扼流圈。
支持标准 | 产品名称 |
---|---|
100BASE-T1 | ACT1210L-201-2P-TL00 |
1000BASE-T1 | ACT1210G-800-2P-TL10 |
总结
从EMC测试结果可以看出,使用了不是为车载以太网设计的共模滤波器/扼流圈时,EMI的噪声抑制效果和BCI的抗干扰性下降。因此,如果使用没有通过OPEN Alliance标准的共模滤波器/扼流圈,会辐射噪声,妨碍无线电等,也可能影响其他通信。另外,S参数的Sdd21特性是影响波形质量的参数,Sccc21特性是影响EMC抑制效果的参数,Ssd21(DCNR)特性是影响BCI耐性的参数。
因此,随着车载网络通信速度的提高,信号质量和EMC问题变得更加重要,所以应当选择在确保符合OPEN Alliance等S参数标准的高电感值的同时,也具备模式转换特性的DCMR(Ssd21)的共模过滤器/扼流圈。
审核编辑:彭菁
全部0条评论
快来发表一下你的评论吧 !