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R
Rafa
Visitor II
May 2, 2024
Question

L293D

  • May 2, 2024
  • 1 reply
  • 644 views

Hi everyone,

 

I'm just starting in this field and I'm designing my first product. I'm designing a device that will use the L293D microchip and I'd like clarification on the following issues:

1) There is a maximum value for the high voltage input current and high voltage enable current. What does this maximum value signify? Is this the maximum safe current the chip should consume from this pin? or is this the maximum the chip is expected to consume and the safe limit for current through this pin is much higher?

2) Following on from the questions above, What is the effect of flowing a much larger current through this pin?

3) How much noise or what ripple voltage can this chip function with?

4) Do you have a sample schematic of the application of this chip or a similar ship?

 

Best regards,

Rafa

    This topic has been closed for replies.

    1 reply

    Peter BENSCH
    Peter BENSCH
    Technical Moderator
    May 7, 2024

    Welcome @Rafa, to the community!

    1. There is a maximum value for the high voltage input current and high voltage enable current. What does this...

      Unfortunately, the data sheet, which dates back to 2003, was written somewhat ambiguously at the time. Both current specifications refer to the input current flowing at the specified input voltage (column Test Conditions). A typical (30µA) and maximum current (100µA) is specified for IIH and only the maximum value for IenH. These values are necessary in order to be able to assess whether the driver capability of the previous stage is sufficient.

    2. Following on from the questions above, What is the effect of flowing a much larger current through this pin?

      If a much higher current flows into the respective pin, the L293D is probably defective.

    3. How much noise or what ripple voltage can this chip function with?

      I assume you are referring this question to the supply voltage? As long as this remains within the specified range of VS, the L293D can continue to operate, but it will pass on the same ripple to the driven load, which may need to be taken into account.

    4. Do you have a sample schematic of the application of this chip or a similar ship?

      You will find many examples of motor controllers on the net using your favourite search engine and e.g. image search.

    Hope that helps?

    Regards
    /Peter

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