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PCM1795 application

Dear Sir

I have try to check if PCM1795 having reference SCH, but just find PCM1795 datasheet figure 51.

For I/V Section, reference design use NE5534(figure 52). it need +/_ power source. may we choice other device that just need postive power device?due to my board just have single power.

Another question is may PCM1795 can direct connect TPA6132? (Could also suggest how to connect?)

                                            Best regards,

                                                              Bogey

 

4 Replies

  • Hi, Bogey,

    Have you looked at PCM5102? I think it might be a little bit easier to use than the PCM1795. You can directly connect the PCM5102 to the TPA6132A2.

    -d2

  • In reply to Don Dapkus:

    Dear Sir

    Good days,

    Now

    May you suggest suit OP(need single power ) for PCM1795 for more good quailty?

                                                               Best regards,

                                                                                Bogey

     

  • In reply to Chen Bogey:

    Hi, Bogey,

    We are looking into this for you.

    -d2

  • In reply to Don Dapkus:

    Hi Bogey,

    I have drawn a draft schematic for your reference(Red circle stands for "virtual ground" point or "half-supply" point):

    What you need to do for single supply is to offer a "Virtual ground" to Op-amp, usually a half-supply voltage. In order to improve the driver capacity, you can also add a buffer to generate the half-supply voltage like this:

    R1 and R2 are equal values selected with power consump-tionvs. allowable noise in mind. C1 forms a low-pass filter to eliminate conducted noise on the voltage rail. R3 is a small (47-Ω) resistor that forms a low-pass filter with C2, eliminating some of the internally generated op amp noise. The value of C2 is limited by the drive capability of the op amp.

    5 V is a common value for single supplies, but voltage rails are becoming lower, with 3 V and even lower voltages becoming common. Because of this, single-supply op amps are often “rail-to-rail” devices to avoid losing dynamic range.

    For Op-amp selection, LME49721 is a better choice because it is a rail to rail input/output Op-amp. Other parts like LME49726(RRO), OPA2353(RRIO) are also suitable for these applications.

    Thank you!