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DAC8162: Oscillations in DAC8162 Output

Vinod Bangar
Prodigy 10 points
Part Number: DAC8162
Other Parts Discussed in Thread: XTR111, OP07
We observed a issue in DAC8162. Following are the details:
At Normal ambient to approx 40C there is no fluctuations in DAC output, after 40 to 45C the device behaves weirdly. There is oscillation in the DAC output when the input given Through SPI is fixed. 
Below is the link of the video for your reference:
We have allowed DAC to give output as 2V constant.  The Fluke reading is the output from DAC.
The 5V Supply to DAC is also constant it is given through XTR111. 
Looking forward for your support. 
Regards,
Pitam M
R&D Design | TEMPERATURE
Telephone +91-9892579309
Selec Controls Pvt. Ltd
Plot No. El-27/1 ,Electronic Zone,
TTC Industrial Area , MIDC , Mahape,
Navi Mumbai -400710,
India.
  • 0
    TI__Mastermind 42133 points

    Hi Pitam,

    We can not access google drive links. Can you attach the video through the insert -> image/video/file option in a new comment? Can you also share your schematic of the DAC8162 and XTR111?

    Best,

    Katlynne Jones 

  • 0 in reply to Katlynne Jones
    Prodigy 10 points

    Kindly check the attached video of the issue.

    Have also attached the schematic.

    --

    Regards,

    Pitam M

  • 0 in reply to Vinod Bangar
    TI__Mastermind 19086 points

    Hi,

    Can you please share your schematics. Whats the load on DAC output?

    Regards,

    AK

  • 0 in reply to Akhilesh K
    TI__Mastermind 42133 points

    Hi Pitam, 

    Thank you for the video, but the schematic did not come through. Can you repost?

    Best,

    Katlynne Jones

  • 0 in reply to Vinod Bangar
    TI__Mastermind 19086 points

    Hi,

    Thanks for the schematics. Are you monitoring DAC output or V0+ and V0- ( I mean jumper on 2 and 3)?

    Regards,

    AK

  • 0 in reply to Akhilesh K
    Prodigy 10 points

    Dear Sir,

    Oscillations are in the DAC Output. 

    Have tested the DAC output with & without further ckts but results remain the same.

    Actually problem was observed via V0+ & V0- , on further investigating found that it was the DAC output which is oscillating.

    Kindly Suggest what has gone wrong.

    Regards,

    Pitam M

  • 0 in reply to Vinod Bangar
    TI__Mastermind 19086 points

    Hi,

    You disconnected current and voltage output stages and checked?

    I think problem is in the voltage output stage with OP07. OP07 amp stage is not stable as per the circuit. Can you remove the load cap and check the same?

    Also why you are using such large resistors 390K and 100K for the gain stage?

    Regards,

    AK