I am FAE in Japanese distributor.
Our customer evaluate ADM2682E and found unnecessary “L” output.
Please see figure1, Figure2 and Figure3.
Could you tell me why RXD output unnecessary “L” ?
Best regards
N.Kokubo
I am FAE in Japanese distributor.
Our customer evaluate ADM2682E and found unnecessary “L” output.
Please see figure1, Figure2 and Figure3.
Could you tell me why RXD output unnecessary “L” ?
Best regards
N.Kokubo
This behavior is related to the dv/dt of the A/B waveform when the driver changes from output H state to high impedance (which happens on the falling edge of the DE signal)
This unnecessary L output can…
Hi Kokubo-san,
This behavior is specific to applications which have small amount of capacitance between the A and B, it is not described in the current revision of the datasheet (Rev G),
There are some…
Hi Neil san
Thank you for quick reply.
I read the following URL and understood small bus line capacitance can be low after DE=L.
https://ez.analog.com/interface-isolation/f/q-a/87001/adm2587e-rxd-problem…
This behavior is related to the dv/dt of the A/B waveform when the driver changes from output H state to high impedance (which happens on the falling edge of the DE signal)
This unnecessary L output can be removed by placing a 1nF capacitor between the A and B pins of the ADM2682E driver. In many applications, the inherent capacitance of the bus cable will be more than 1nF and a discrete capacitor may not be needed,
Regards,
Neil
Hi Neil san
Than you for your advice.
Could you tell me where in the datasheet dv/dt of A/B waveform is mentioned?
Best regards
N.Kokubo
Hi Kokubo-san,
This behavior is specific to applications which have small amount of capacitance between the A and B, it is not described in the current revision of the datasheet (Rev G),
There are some more details in previous posts here:
https://ez.analog.com/interface-isolation/f/q-a/87001/adm2587e-rxd-problem/178964#178964
Regards,
Neil
Hi Neil san
Thank you for quick reply.
I read the following URL and understood small bus line capacitance can be low after DE=L.
https://ez.analog.com/interface-isolation/f/q-a/87001/adm2587e-rxd-problem/178964#178964
Best regards
N.Kokubo
Hi
I will close this question
Best regards
N.Kokubo