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TIDA-RESOLVER-APPLICATIONS-REFERENCE-DESIGN: TIDA01527

Yakshraj Sharma
Prodigy 80 points
Part Number: TIDA-RESOLVER-APPLICATIONS-REFERENCE-DESIGN
Other Parts Discussed in Thread: TIDA-01527, TIDM-02014

Tool/software:

hi all

,

i am working on TIDA-01527 for insuring the smooth working of resolver. i have question relates to below circuit

because of input AM signal coming, differential amplifier does it pass directly or further circuits are filtering instead of passing only envelop because, R32 and C15 does only here as a bucket filter. i have to configure the resolver with sincos encoder. so, does the output of OSIN and OCOS is enough or any filter require in between of them. if yes, then how to calculate the parameter(cutoff frequency and  filter order) for the smooth angle configuration?  

best regard,

thankyou!

  • 0
    TI__Prodigy 60 points

    Hi Yakshraj,

    The output signal from resolver is always sine/cosine envelope with high frequency excitation signal. Hence, differential 2nd order low-pass filter can be implemented to filter the excitation frequency. Please find the filter designed for resolver in traction inverter reference design TIDM-02014, which can be used as a reference. Could you please provide the excitation frequency and maximum operating frequency of the resolver?

  • 0 in reply to Yuxin Liu
    Prodigy 80 points

    hi Yuxin,

    thank you and I appreciate your quick reply. 

    The modulated output of resolver sin+, sin -, cos+ and cos- is 10kHz and excitation voltage 7VAC, pole 4 and TF ratio 0.286+/- 10%.

    so, should I change(TIDA-01527) according to your TIDM-02014 (Res_sin_N)?

    thanks,

  • 0 in reply to Yakshraj Sharma
    TI__Prodigy 60 points

    Hi Yakshraj,

    Yes. the circuitry in your screenshot is just a differential op-amp circuit and the output signal is still the sine/cosine with high frequency excitation harmonic, which is used for monitoring the output signal as the feedback. If you want to get the sine/cosine envelope, you can add such a filter shown in TIDM02014. Please note that the filter will cause a little phase shift and then generate some angle error.

    Best regards,