UJA1169 CAN 无法通信

[chz]

CAN 总线通信时，发现CANH CANL RX TX 波形如下：

其中CANH最高可以到达7V，测量CANH,CANL 和VBAT 之间电阻，电阻阻值为无穷大，测量CANH,CANL 和GND ，阻值无穷大。测量CANH,CANL 之间电阻为120欧.CANH和CANL对外未连接任何设备。

请帮忙分析一下原因。

[chz]

When CAN bus communication, CANH CANL RX TX waveform is found as follows:

CANH can reach up to 7V, and the resistance between CANH,CANL and VBAT is measured, and the resistance value is infinite. CANH,CANL and GND are measured, and the resistance value is infinite. The resistance between CANH and CANL was measured to be 120 ohms. CANH and CANL are not connected to any devices externally.

See the attachment for the schematic diagram

[TomasVaverka]

Hi,

Could you please translate your question into English to avoid any misunderstanding during an automatic translation?

It might be useful to share also your schematic especially around CANH and CANL pins and the full UJA1169 part number you are using.

Here are the limits for the dominant and recessive states:

BR, Tomas

[chz]

When CAN bus communication, CANH CANL RX TX waveform is found as follows:



CANH can reach up to 7V, and the resistance between CANH,CANL and VBAT is measured, and the resistance value is infinite. CANH,CANL and GND are measured, and the resistance value is infinite. The resistance between CANH and CANL was measured to be 120 ohms. CANH and CANL are not connected to any devices externally.

See the attachment for the schematic diagram