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Positive voltage with DAC8801 and 1 amp op

Other Parts Discussed in Thread: DAC8801, DAC8550

Hello. In previous work, I have held the topology of the image, but with different DAC (as the AD755), for positive voltages without any problem. It seems an easy, simple that does not require many components. In the application I'm currently developing, I need a working DAC 3.3 V to generate a voltage of about 1.39 V. The DAC8801 seems like a good option, and seeing the inner configuraion (block diagram, the pinout and network R- 2R), I think it would work. My question is basically if it worked. It is a very area open question, but if there is any reason that could fail, I would like to know it, because reading the data sheet, I do not see any. Thank you very much for all your replies.

Hola. En trabajos anteriores, he ocupado la topologia de la imagen, pero con DAC diferentes (como el AD755), para obtener tensiones positivas sin ningun problema. Me parece una forma facil, sencilla que no requiere muchos componentes. En la aplicacion que actualmente estoy desarrollando, necesito un DAC que trabaje a 3.3 V para generar una tension de aproximadamente 1.39 V. El DAC8801 me pàrece una buena opcion, y viendo la configuraion interna (diagrama de bloques, el pinout y la red R-2R), me parece que funcionaria. Mi pregunta es basicamente si funcionara. Se que es una pregunta muy abirta, pero si hay alguna razon por la que podria fallar, me gustaria saberla, por que leyendo la hoja de datos, no veo alguna. Muchas gracias por todas sus respuestas.

  • Hi Javier,

    I don't think this will work with newer high resolution Multiplying DACs.I do know that 16-bit devices have reduced linearity when used in this configuration. I need to gather more information from our designer to see of I can give you some more insight into how much this problem will affect a 14-bit device.

    As an alternative, I can try to suggest a different device for your application. What features are attractive to you about the DAC8801 in particular?

  • Thank you very much for the reply, Eugenio. The supply voltage (the application works with 3.3 V), the resolution and three-wire interface. The main thing is to get what I need: Getting around 1.39 V and this value can vary up and down as needed.
  • I would recommend that you take a look at the DAC8550. It is a 16-bit DAC that requires an external reference. You can vary the input reference up and down, up to VDD. The reference impedance does not change with the code so you don't need to buffer it.

    The DAC8550, does not have a relative accuracy or integral non-linearity (INL) as good as the DAC8801. Since you didn't mention the accuracy, maybe it is not as critical for your application. But I can help you figure it out if you are in unsure.
    Do you know how many steps you require between 0V and 1.39 V (or another target output voltage).
    What is the size of the steps?
    What is the error band that you can tolerate for each step?