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OPA564-Q1: compatibilty for resolver application

Part Number: OPA564-Q1
Other Parts Discussed in Thread: ALM2402F-Q1, ALM2402-Q1

Hi,

We are using AD2S1210 resolver to digital converter for our application. For the amplification of the excitation signal, we need high output current and high slew rate amplifier.

We are thinking to use OPA564-Q1 for this. Our supply voltage will be between 12V to 15V.

1. Will be good to use this ? We need AEC-Q qualified. 

2. We need dual Op-Amp. Can you suggest any alternative parts?

Thanks in advance.

Best regards

Sifat

  • Hi Sifat,

    One possibility is the ALM2402F-Q1.  The ALM2402F-Q1 is a dual operational amplifier with high current drive (400mA) and slew rate (3.4-V/us) supporting up to 16-V supply that is AEC-Q1 qualified. The main application for this device is resolver-based automotive applications (output for resolver excitation).

    Please see link for product page below. Please let me know if this device meets your requirement or please let me know your current drive, slew rate and excitation voltage frequency requirements.

    Kind Regards,

    Luis

    ALM2402F-Q1 Automotive, Dual Operational Amplifier With High Current Output for

    Resolver Excitation

    http://www.ti.com/lit/ds/symlink/alm2402f-q1.pdf

  • Hi Luis,

    Thank you for your quick reply. Our slew rate requirement is 0.63 V/us (minimum). The voltage requirement is 10 Vrms @ 10 kHz. Previously, we used ALM2402-Q1, which was distorting the excitation signal for high gain due to less slew rate. 

    1. I checked ALM2402F-Q1, but this is not available in digikey or Mouser. 

    2.  Can we use OPA564-Q1 for this application? if not, Can you suggest any alternative part?

    Thanks

    best regards

    Sifat

  • ALM2402F-Q1 is in preproduction – only available from TI store:

    https://www.ti.com/product/ALM2402F-Q1/samplebuy

  • Hi Sifat,
    ALM2402F-Q1 is in preview/pre-production – samples are available on TI store.  The device is expected to fully release to manufacturing within a month.
    The ALM2402F-Q1 has higher slew rate and higher bandwidth than the ALM2402-Q1.  The OPA564-Q1 easily exceeds the slew-rate and current drive requirements for a resolver application; however, this device is not available on a dual package and may be over kill for a resolver application.
    - I want to ensure the amplifier has enough supply headroom to support the resolver signal.  Please clarify the voltage supplies, current load and amplitude requirement of the 10-kHz signal.  The post above mentions that the signal amplitude requirement is 10-Vrms, and the supply requirement is between 12-V and 15-V.    Keep in mind, 10-Vrms is a 14.1-Vpeak signal that may exceed the amplifier output swing requirement when using a 15-V supply.  
    To ensure the amplifier has enough supply headroom and to ensure the amplifier remains inside its linear region, it is important to review the output swing requirements on the AOL (open loop gain) specification.  Looking at the OPA564-Q1 AOL datasheet spec, the amplifier supports output swing of 2V from the positive rail and 2-V from the negative rail.  Similarly, looking at the ALM2402F-Q1 AOL datasheet spec, the amplifier supports output swing of 1.4V from the positive rail and 0.3-V from the negative rail.  
    Thank you and Best Regards,
    Luis  
  • Hi Luis,

    Thank you for your quick reply.

    The voltage requirement 7 V-rms. Sorry for my mistake. The current load is around 200 mA-rms (max) and frequency is 10 kHz.

    So, ALM2402F-Q1 could be the best option, right?

    Thanks again

    Best regards

    Sifat

  • Hi Sifat,

    Yes, the ALM2402F-Q1 is a good option, should be able to support the 200-mA rms (max)

    Please let us know if you have additional questions.

    Many Thanks,

    Kind Regards,

    Luis