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MAX1488E / MAX1489E replacement

Charley Henderson
Prodigy 10 points
Other Parts Discussed in Thread: SN75189, SN75188

Looking to replace the MAX1488E / MAX1489E quad RS232 line drivers / receivers in an exisiting design with a lower cost alternative.

Requirements are:

- RS232 V.28. 4x transmit and 4x receive lines.

- Line drivers need to operate from exisiting +/-9V rails. i.e. no internal charge pump required. Input is 3.3V logic from processor

- Line receivers need to operate from a +5V or +3v3 rail. Output is 3.3V or 5V logic to a processor

- ESD protection, minimum ±8kV air discharge, ±4kV contact discharge. Either built in or as a separate IC.

Would the SN75188/SN75189 be suitable, as these appear to be low cost? In which case is there a standard application circuit.

Any support/advice greatly appreciated. 

  • 0
    TI__Guru*** 149776 points
    Charley,

    These two drivers date back to the 1970's. I could not find ESD data in the database. I would expect the ESD performance to be poor by today's standards.
    The SN75188 should work well with a 3.3V CMOS input. The schematic shows an input threshold of 2 diodes (about 1.4V).
    SN75189 is designed for 5V operation only. However, I expect it would also work with 3.3V supply.

    IEC ESD would need to be added externally. There is no specific application circuit, but operation is simple. RS232 on one side and logic on the other.