Dear TI Team
Our customer is considering THVD1450.
If I use only the driver part of THVD1450, how should I handle the unused R and RE pins?
Also, if only the receiver part is used, how should the unused D and DE pins be handled?
Regards,
Y.Ottey
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Dear TI Team
Our customer is considering THVD1450.
If I use only the driver part of THVD1450, how should I handle the unused R and RE pins?
Also, if only the receiver part is used, how should the unused D and DE pins be handled?
Regards,
Y.Ottey
This device has integrated pull-up/-down resistors; all unused pins can be left open (see section 9.4.3 of the datasheet).
If you have a very noisy environment and fear that the resistors might pick up noise, you can connect DE to GND and D and RE to VCC.
Y.Ottey,
You can deactivate either function of the device using the DE and RE pins. Leaving DE floating would disable the driver, as an internal pull-down resistor would bring this to a logic low.
Similarly, leaving RE floating would disable the receiver, as an internal pull-up resistor would bring this to a logic high.
I rarely recommend putting floating input pins into a design, so if either portion of the device is to be disabled, I recommend pulling the DE or RE pin to VCC or GND as applicable.
I especially recommend considering a pull-down for DE if the driver is not used. If a noisy environment somehow causes the driver to become temporarily enabled, it could cause bus contention or data corruption even if D is also left floating.
Unused digital outputs (pin R) can be left unconnected if necessary.
Best,
Danny
Dear Danny
Thank you for your reply.
I have confirmed what you have described.
From what you have stated, I have the following perceptions:
Is there any problem with the following recognition?
(1) Connection of R and RE pins when using only the driver part of THVD1450
(2) Connection of D and DE pins when using only the receiver part of THVD1450
Regards,
Y.Ottey
Y.Ottey,
Y.Ottey said:
Looks like we agree. The open RE pin disables the receiver, and the open DE pin disables the driver.
Best,
Danny