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LM358BA: Need Right Product selection guide

Naveen K1
Intellectual 900 points

Part Number: LM358BA
Other Parts Discussed in Thread: LM358B, ISO7762, AMC0311S, ADS7042, ADS8675, AMC0311R, AMC4311R, AMC131M01, ADS7253

Hi,

  1. Earliesr we used LM224DR 4channel, we need same specification in 2 channel. LM358BA or LM358B can be used to replace LM224DR and keeping the same supporting circuit? 
  2. I want to measure Welding Torch Voltage using simple voltage dvider and need to isolate. Kindly suggest the suitable Isolated Amplifier, we use SPI interface External ADC between Amplifier and MCU.
  3. Any drawback on Isolated Amplifier? Can we use Isolated Amplifier or we need to use Isolator ISO7762 with ADC, which is best option.

Thanks and regards,

Naveen K

  • 0
    TI__Expert 7890 points

    Hi Naveen,

    Yes, the LM358B offers similar behavior as the LM224DR in a 2-channel device. Please refer to the below table for a comparison between the two devices.

    I will loop in the isolators team to help with your remaining questions.

    Best regards,
    Carrie

  • 0 in reply to Carrie
    TI__Mastermind 22986 points

    Hi Naveen,

    Can you please provide more information about your application? What are the voltage domains in regards to isolation that your system is supporting? a general block diagram would be very helpful to understand your system.

    My team supports digital isolators, isolated interfaces, and several other devices. So I am essentially trying to see if your application needs a digital isolator like the ISO7762 that you have mentioned, or if it requires an integrated solution like the isolated ADCs or amplifiers.

    Regards,
    Aaditya

  • 0 in reply to Aaditya V.
    Intellectual 900 points

    Hi Aaditya,

    Thank you for your support.

    We need to monitor/measure Welding Machine Voltage (Source is 0-110Vdc) and Current (Source -4 to +4Vdc) as shown in block diagram.
    Need Isolation between Voltage source (110V) and MCU. No Isolation required between Current(Source -4/+4) and MCU.
    1. Kindly suggest your best advice's on this block diagram.

    2. We need Isolated amplifier or Isolated ADC or Dedicated Isolator?

    Thanks and regards,

    Naveen K

  • 0 in reply to Naveen K1
    TI__Mastermind 22986 points

    Hi Naveen,

    Please allow me an additional day to review and respond.

    Regards,
    Aaditya

  • 0 in reply to Aaditya V.
    Intellectual 900 points

    Hi Aaditya,

    Good Day!
    Noted.

    1. We struck in conclude whether Isolated Amplifier will be best or after ADC Digital isolator will be best? Option A or Option B in the following Block diagram.
    2. Kindly suggest us Option 1 is best or Option 2 is best and please suggest the OPAMP (if for Isolated OPAMP) & ADC accordingly.

    We went through the ADC & Isolated Amplifier in the TI website, could not able to find right ADC's in single ended input in 2 channel's.

    In 1 channel we shortlisted ADS8675 and ADS7042. If we go with Option-B, shortlisted Isolated Amplifier is AMC0311S.

    3. Please suggest us the best OPTION-A or B and suggest us the  suitable ADC's in 1CH and 2CH & Isolated Amplifier  which is suitable for our Block diagram.

    4. Also please advice 3.3VDC will be sufficient for both AVDD & DVDD or 5V mandatory for AVDD.

    5. Also please advice internal reference will be sufficient or External Voltage reference will be Good on better accuracy?

    Thanks and regards,

    Naveen K

  • 0 in reply to Naveen K1
    TI__Mastermind 22986 points

    Hi Naveen,

    Thank you for the additional details and clarification. I will be talking to my colleagues to make sure I can confirm and respond to you by Friday. 

    Regards,
    Aaditya

  • 0 in reply to Aaditya V.
    TI__Mastermind 22986 points

    Hi Naveen,

    Thank you for the additional details and explanation. Looking at the block diagram, I believe the Option B with an isolated amplifier would be more beneficial for your application. By having an isolation barrier before the ADC and MCU, you can keep the two devices safe from any transients or overvoltage from the HV side. With option A, the digital isolator would only be protecting the MCU while the ADC would be susceptible to overvoltage from the HV side. 

    Considering this, please allow me to transfer this thread to the Isolated Amplifiers team.

    Regards,
    Aaditya

  • 0 in reply to Aaditya V.
    TI__Expert 7670 points

    Hi Naveen,

    Below are 3 good options for you.

    The AMC0311R should work well for you, but it will need a high side supply.  It has a 0-2V input range, so the voltage divider should be adjusted accordingly.  The output is single-ended and ratio-metric, so you can use the same ADC Ref voltage to scale the output to the same range as the ADC. 

    The AMC4311R is the same as the AMC0311R but with the DC-DC integrated, so no high-side supply is needed.

    The AMC131M01 is also an option.  This device has a SPI output and integrated DC-DC, so no additional high side power supply is needed on this either.

    Let me know if you have any questions on the above.

    Thanks.

  • 0 in reply to Saleh Ahmad
    Intellectual 900 points

    Hi Saleh Ahmad,

    Thank you for your Support!

    AMC131M01 production status is in Preview and we may face Leadtime issue. We may consider AMC0311R and we are having following Query 

    1. Recommended on datasheet, Higher side VDD1 is 5V and  Lower side VDD2 is 3.3V and Vref should be GND2 right? Please advice we can keep Vref is GND2 or we need to connect with ant external Voltage source or 3.3V?

    2. As per the datasheet circuit, can we  use R1+R2= 550K and RSNS=10K?

    3. If the INP=2V, OUT=2v only right? Rail to Rail?

    4. OPAMP output side We use ADS7253 ( 2CH fir two sources), for RC filter 10E with 10nF will be Good or please suggest Best values, we run at 1ksps sample..

    5. Regarding ADS7253, can we use internal Reference Voltage or External Vref is recommended?

    6. Can we short REFIO_A & REFIO_B or we should keep separate?

    7. Hope Recommended AVDD is 5V, VDD is 3.3V ,right?

    Thanks and regards,

    Naveen K