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