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PGA300: PGA300 vs PGA302

jw
Expert 1190 points
Part Number: PGA300
Other Parts Discussed in Thread: PGA302, , PGA305

In what usage case would the PGA302 have an advantage over the 300? 

  • 0
    TI__Mastermind 31655 points

    Hello JW,

    The PGA302 is a simpler device than the PGA300. The PGA300 has 2 ADCs (one for temperature one for pressure) each with a 16 bit resolution. It also has the ability to produce a 4-20mA current loop output in addition to absolute or ratiometric voltage output. This part can only be configured through OWI. The input voltage range for the PGA300 is 3.3-30V.

    The PGA302 has a single 16 bit ADC for both pressure and temperature (it is muxed to each of the corresponding PGAs), and only has the option for a 0-5V ratiometeric voltage output. It also can be configured through I2C or OWI. The input voltage range for the PGA302 is 4.5-5.5V.

    The PGA300 has greater flexibility, but with additional configuration effort required.

    Regards,

  • 0 in reply to Scott Cummins
    Expert 1190 points

    Hello Scott, PGA3XX small size and HW integration make it suitable for our application, but I have several lingering electrical question and need a sanity check

    The sensor voltage is 12V, therefore the INp and INn will sit 6V above ground, exceeding the reference voltage of 2.75V, is this a problem. does the PGA305 address this issue?

    Again Packing is a primary concern which is the reason for selecting the device, we prefer to use the I2C to read the ADC value. What accuracy can be expected with no calibration? 

    thanks!

          

  • 0 in reply to jw
    Expert 1190 points

    hello Scott, your thoughts

    thanks

  • 0 in reply to jw
    TI__Mastermind 31655 points

    Hello jw,

    The PGA305 datasheet provides the single-ended input limits for the PGAIN and TGAIN amplifiers, and they are up to 1.8V. 6V is well outside the limits, and you will have to divide the voltage down before it is applied to the input pins.

    The total output accuracy of the system is only specified based on a calibrated PGA305/300/302 with a resistive bridge emulator. The uncalibrated output will certainly be less accurate, but I can't provide anything more specific because it will depend on your sensor. The ADC specifications are included in the datasheet and can give you a picture of its performance on its own.

    Regards,