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Obsolete device datasheet / information TMC1112A

Andrew Denham
Prodigy 60 points
Other Parts Discussed in Thread: TLV320AIC1110

Good day,

I have to replace a TMC1112A signalling circuit in a telephone PCB that we manufacture. All supplies of this device have now dried up.

The original device seems to have been made by Hughes or Raytheon, but also by Plessey and Texas Instruments during the 1990s. It is essentially a DTMF dialler. I am trying to find any available data on this device to help redesign the board.

Does anyone have the datasheet or any information on the device? I have trawled the internet extensively but there is nothing available.

Any help would be appreciated.

  • 0
    Prodigy 5 points
    Hello Andrew,
    Thank you for posting.

    I find no reference to a TMC1112A in TI's archives.
    I do see an application note on how to make a DTMF dialer.
    www.ti.com/.../snoa148.pdf
    AN-666 DTMF Generation with 3.58 MHz Crystal
    This application note outlines two different methods of DTMF generation using a COP820C/840C microcontroller
    clocked with a 3.58 MHz crystal in the divide by 10 mode.
    This yields an instruction cycle time of 2.79 ms. The application note also provides a low true row/column decoder for
    the DTMF keyboard.

    TI 's obsolete device inventory is handled by Rochester Electronics
    Part numbers may be searched for here: https://www.rocelec.com

    The TLV320AIC1110 PCM Codec will produce DTMF for communications applications.
    www.ti.com/.../TLV320AIC1110
    This device was introduced in 2001.

    There are other references to DTMF on TI's website that may be searched for.

    Do you have any other information you can provide?