Is there supposed to be a non zero voltage at the MAX3232 R1_OUT/R2_OUT TTL terminals?

If the device is powered off (Vcc=0V) and an external RS232 peripheral is driving the R1_IN or R2_IN inputs, we have noticed that non-zero voltage can appear at the R1_OUT/R2_OUT TTL terminals. Is this the expected behavior of the IC?

As to the Rin voltage pulling up on the VCC line and Routs.
Yes, there is a path that will pull up the VCC from the Rin, but you cannot pull much current out of the VCC or Routs since the path is a very weak one.

 

Tags: interface and isolation MAX3232 non zero voltage R1_OUT R2_OUT Show More
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