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PCA9535: Difference between parts

Part Number: PCA9535
Other Parts Discussed in Thread: TCA9535, TCA9555, PCF8575, PCA9555, , TCA9539, TCA9539-Q1

Hello,

I had a look at different I2C to GPIO devices and came across those parts TCA9535, PCA953, TCA9555, PCA9555, PCF8575C and PCF8575.

Can you please explain what is the difference between them?

Best regards,

Timur

  • Timur,

    The TCA versions of these devices are the newer versions of their PCA counterparts. This means that TCA9535 is the newer and better-performing version of the PCA9535, and same for TCA9555 vs. PCA9555.

    the PCF8575 has a current source for actively driving high at the output pins. The PCF8575C does not have this. You can see the differences in the "Simplified Schematic Diagram of Each P-Port Input/Output" figures in each data sheet.

    PCF8575:

    PCF8575C:

    Best,

    Danny

  • Hello Danny,

    Thank you for your reply

    What is the difference between PCA9535, PCA9555 and PCF8575?

    Best regards,

    Timur

  • Timur,

    The TCA9555 is identical to the TCA9535, except for the inclusion of the internal I/O pull-up resistor, which pulls the I/O to a default high when configured as an input and undriven.

    The PCF8575 and PCF8575C are not as closely related to these aforementioned two parts. There are multiple feature differences, most notably that the the PCF devices do not implement configuration registers. Also, the TCA9539 and TCA9539-Q1 have reset pin functionality while the PCFs do not.

    I recommend checking out ti.com/i2c and clicking "General-purpose I/O (GPIO) expanders" to use the product portfolio and filtering down the products. Looking at this filter of all 16-pin devices, for example, you should easily be able to compare devices by checking out the "Features" column.

    Best,

    Danny