• AD7658-1 tconv > 3.1us

    We have a mature design that uses the AD7658-1 and have noticed that the conversion (tconv) time is exceeding 3.1us at -40°C.  Datasheet figure 17 indicates that tconv will increase as temperature drops, but it does not show it going above 3.1us.  Page…

  • RE: AD7658, queries for current consumption

    Hi Karen,

    Thank you very much for your answer.

    In regards to supply current, please let me ask you more.

    About the feature of the analog input, how does it different between AD7658 and AD7658-1 ?

    If it is clear what is different, we may assume why…

  • RE: AD7656 occasional bad data 2

    Hi Joan,

       You mentioned that the reference used was 5V but in the schematic it says internal with REFen/dis pin equal to Vdrive. Please take note that the AD7658 reference voltage range is 2.5V.

       Have you apply reset on the AD7658? After power up, it is…

  • RE: 急,AD7658已经烧损了十几片了,请帮忙解决

    1. 测试操作时不要热插拔板卡.

    2. 板卡上电后, 再加模拟输入信号.

    3. 要注意AD7658的上电时序, 建议控制上电时序VDD/VSS->AVCC->DVCC->VDrive. 负电源VSS不要先于正电源VDD上电.

    4. 控制VDD, VSS电源的电流输出能力也有作用, AD7658的VDD, VSS只需要1mA的电流, 电源供电电流输出能力几十mA即可.

  • AD7658 output comnparison problem

    Hi all,

    I'm using ad7658 in parallel mode. I have written my own fpga code to read the analog inputs. In simulation it works regularly but i can't see the true results at the outputs when i change it input voltage value.

    In oscilloscope, the…

  • RE: AD7658 -reading data

    Schematic was made in quartus using block diagram. I am using Altera MAX II in my project.

    Others pin:

    H/SSEL is set to low

    SER/PAR is set to low

    RANGE is set to high

    W/B is set to low

    Message was edited by: Michał Kuklewski I found also this schematic…

  • AD7658的正负供电电源问题

        最近正想用AD7658采集双极性信号,AD7658要求要用双极性的供电电源,有没有一款电源芯片能够将单极性的正电源输入转换为对称的双极性的电源输出,这样使用双极性的AD芯片就方便多了。以前用7812跟7912搭建的正负12V的电源太笨拙了…………

  • Re: [Precision ADCs] - Re: AD7656 occasional bad data 2

    Dear Jonathan,

    Thank you for your response. I send you an e-mail instead of using the

    EngineerZone of the webpage because I have attached some documents.

    The response to your inquiries is described below.

    1) Description of the problem:

    As I commented…

  • RE: 请教ADI工程师AD7658设计问题

    建议你使用AD7658-1,对去耦的要求降低,更方便使用。您的电源方案是可以的,建议用线性稳压器,譬如ADP7102。关于驱动输入芯片,选取手册上推荐的元件即可。如果想详细了解驱动放大器参数和ADC的关系,请参考此文章:

    http://www.analog.com/library/analogDialogue/archives/46-12/sar_front_end.html