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MAX3232: Output resistance of Driver

Guru 29690 points
Part Number: MAX3232

Hi Team,

The datasthee shows the following about "Output resistance" of Driver.



It shows 10Mohm is typical and 300ohm is minimum value and the value between these is quite a large.
What does the value indicate?
I couldn't catch why the datasheet shows minimum value for output resistance. 

Best Regards,
Yaita / Japan disty

  • Yaita,

    The minimum ro indicates the driver's driving capability. Let's say the load is 3kOhm, 300Ohm resistance would take 10% of voltage supply. The spec makes more sense here may be Voh and Vol, which guarantee 5V voltage swing with 3kOhm load. These spec make sure the output voltage meet RS232 standard while taking ro into account. Please let me know if you have other questions.

    Regards,

    Hao   

  • Hi Hao-san,

    Looking at the ro specification again, ro indicates output resistance under "VCC, V+, and V– = 0 V" condition.
    The typical value is 10Mohm at Ta=25°C when no supply and there is possibility to shift down to 300ohm under Ta=-40°C to 85°C (MAX3232I).
    Is my understanding correct?

    Best Regards,
    Yaita

  • Yaita,

    Your understanding should be right. I didn't notice Vcc could be zero voltage.

    Regards,

  • Hi Hao-san,

    Thank you for your kind reply!

    Best Regards,
    Yaita