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Wich Supply Voltage for the AD688 is necessary?

Hello community,

I need a high precision reference voltage for my 16 Bit DAC, so i decided to use the AD688.

In the Datasheet the IC is supplyed by a voltage of +-15 V, but in my circuit I have only +-14 V or less.

Is it possible to use the AD688 with a +-14 V or +-13 V power supply insted?

best regards


  • Hi Fabian,

    Currently I'm not sure what is the minimum voltage supply that the AD688 will work, but I'm looking in to this and will get back to you as soon as possible.

    In my speculation, it will work on +-14V. This is because, as you may have notice, the Line Regulation is tested at +-18V and at +-13.5V. But this is the only specs that is tested on this voltages. Other specs values will be near to the current value though, but not exactly.

    Is there a reason for the +-14V? Considering normally the voltage supplies are normally specs at +-15,20, or 25.



  • Hey Mon,

    thank you for your response.

    Of course I noticed the maximum ratings and the specs of the Line regulation...

    I'm designing a low noise circuit, which is basically a femto ampere current source with a 16 Bit DAC as regulation. So I need a very precision reference to manage the 16 Bit. To prevent power loss I want to use a +-15V and 5V switching regulator with a ultra low noise LDO behind. The LDO are the LT3045 and LT3094. The maximum input voltage of these are 20V and I can adjust the output voltage by a single resistance. To prevent heat and because its a unique pcb +-14V is ok for me.

    I also think that +-14V will work but I thought that maybe someone had already tested it so I can be sure. It's kind of sad, because it is a very expensive IC so I would expect a clear declaration about the min and max supply voltage.