• AD7985 datasheet question

    I have question regarding AD7985 3-wire interface mode without busy indicator (Figure 27 in datasheet). In page 18 of the datasheet, the number of bits that can be read during conversion is calculated by multiplying tDATA with fSCK. Then Figure 27 shows…

  • Questions for your AD7985

    Dear Sir/Madam,

    I am just studing to use your AD7985 with your datasheet page.19, Fig 27 CSB Mode, 3-Wire Without Busy Indicator Serial Interface Timing (SDI High) condition. Also I will be worked AD7985 with fix the procedure of conversion and acquition…

  • AD7985芯片SDO管脚中断输出问题

    AD7985芯片已设置为/CS模式(三线式且有繁忙指示)。

    设置方法:TURBO管脚下拉,SDI上拉,SDO接10K的上拉。输出给CNV时钟(1.953Mhz);

    问题现象:CNV时钟保持高电平20ns时发现SDO脚一直是低电平,无法检测到中断。后来将CNV时钟的高低电平翻转发现SDO脚上升到高电平是个缓慢的过程。按照手册上描述CNV有上升沿启动转换SDO即进入高阻态。这是有上拉情况下应该立刻变高。为什么出现缓慢上升的过程呢?

      怎么解决?急求,谢谢!@

  • 关于AD7985芯片进行数据读取的问题

    我用STM32来对AD7985进行控制,进行电压采集,使用的是最简单的三线式无繁忙指示。在输入端给3.3v的直流电压,但是采到的电压值都是些毫无规律且一直在变动,具体的程序是按照数据手册里的时序一步一步来的,我不知道是不是时钟或者延时什么的没有设置好,求帮帮忙,挺急的,网上也没什么资料,下面附上时序图和部分程序。

  • AD7985时钟偶尔出现异常,导致数据输出异常的问题

    1AD硬件电路,采用/CS模式,三线式且无繁忙指示。

    2、AD7985SPI输出端口配置如下:

    • SDO   AD输出
    • SCK      22.5Mhz
    • CNV     转换
    • SDI -----------2.5v常高
    • TURBO--------GND 常低电平

     

    3、下图为逻辑分析仪采集的时序。其中,黄色框里是正确的波形,SCK为16bit,输出SDO输出正确的数据;但是红色框里SCK为64bit,SDO输出全是0。


  • RE: A/D USB interface for Si amplified photodiode

    Hi, Vincent.

    The 16-bit AD7985 was used together with a flexible sensor signal conditioning block which can be used for accurate smallsignal measurements in this reference circuit. The AD7985 has an input voltage range of 0-Vref (Vref can be externally…

  • AD8253 Single input circuit?

    This is the reference circuit about the AD8253 and AD7985.

    There are differencial input ports in the AD8253 and I want to use this device for single input.

    Then how can I connet the other input pin?

  • Best ADC for High voltage inputs?

    I’m trying to decide which ADC to use for a high voltage front end.  Here are the requirements for the ADC:

    Fixed input range +/- 50V

    16 bit resolution

    10 Meg input impedance

    1 MHz Bandwidth

    2 or 3 MSPS or greater

    Serial or SPI output

    I’ve been…

  • RE: ADC evaluation board choose

    Hi Yake,

    I have attached a list of some of the ADCs that fit your criteria of 2MSPS sampling rate or higher at resolution of 12bits or more.

    You may also wanted to check the ADI website and do a parametric search (http://www.analog.com/ps/psthandler…

  • RE: ADC with really "True differential input"

    Hi vlad8016,

             What Klaus mentioned are right. There are three most common types of ADC input structure a.) Single- Ended b.) Pseudo Differential c.) True Differential.  From your description above I can see that you are looking for ADC that has a pseudo…