ISOW7842: ISOW7842 and TRS3232 | Schematic Review

NAD

Part Number: ISOW7842
Other Parts Discussed in Thread: TRS3232,

Tool/software:

Hello,

Schematic review for ISOW7842 and TRS3232:

Using the TRS3232 and ISOW7842 for a RS-232 link between two custom PCBAs to provide isolation (prevent ground loops, etc.) -- both PCBAs would have the same circuit schematic as shown below.

It looks like the ISOW7842 does not need a pull up on the RS-232 TX line - wondering if anyone has used these two parts, correct?

over 1 year ago

+1 Clemens Ladisch over 1 year ago

Guru 317250 points

OUTB is always active, so no pull-up is needed on that line. (And it's default high when the input signal is missing, so no pull-up is needed on UART2_TX.)

0 Koteshwar Rao over 1 year ago

TI__Guru 55815 points

Hi NAD,

Thank you for reaching out.
As Clemens stated, I wanted to confirm that INB and OUTB pins do not require external pull-up resistors. Not sure if you have seen the below reference design, I am sharing it here for your reference. Thanks.

https://www.ti.com/tool/TIDA-01230

Regards,
Koteshwar Rao

Isolation

Isolation forum

ISOW7842: ISOW7842 and TRS3232 | Schematic Review