Isolate RS485. TI's ISO1450 chip has no output at the A end, but normal output at the B end. Please help me

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Isolate RS485. TI's ISO1450 chip has no output at the A end, but normal output at the B end. Please help me [Copy link]

This is the schematic diagram of this chip. When the RE and DE pins are high, the chip is in the sending mode. At this time, the waveform at the B end is normal and there is no output waveform at the A end.

damiaa

Download a manual for you so that others can read it easily ISO1430.PDF (3.82 MB, downloads: 6)

2024-4-15 14:44 上传

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Check whether there is a signal from the CPU serial port TX to the D end of this chip.

Check whether there is voltage on both sides.

Disconnect the line from 485 to other devices

If all the above are OK, I wonder if the port of the chip is broken? If possible, you can check multiple boards or chips.

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damiaa posted on 2024-4-15 14:45 I will download a manual for you so that others can read it conveniently

grateful!

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damiaa posted on 2024-4-15 14:45 I will download a manual for you so that others can read it easily. Check whether there is a signal from the CPU serial port TX to the D end of this chip. Check the voltage on both sides...

There is a signal from tx to D. The power supplies on both sides are normal. Left VCC1: 3.3V Right VCC2: 5V. Currently, the 485 chip on my board is only connected to the serial port.

dcexpert

The full-duplex and half-duplex pins are different, check to see if you have made a mistake.

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dcexpert posted on 2024-4-15 15:28 The full-duplex and half-duplex pins are different, check to see if you have made a mistake.

I used full duplex, which is not wrong. I only left the A and B pins, and Z and Y were not used.

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Solved it or I didn't read the data sheet carefully. The full-duplex output pins are B and Z. Generally, when you see a 485 chip, they are A and B. Thanks to the masters

eew_vuUGKG

Is the chip broken?