• RE: AD9674 TGC Gain input driver

    Hi Gsing,

    With the negative power supply, the circuit is easy, and the ADA4938 is the right part. Using the circuits in the CN0181 and ADA4938 is ok for your design, but I do not think the ADA8657 is good candidate due to bigger noise and small GBP.…

  • 使用ADA4938驱动AD9204的问题

    在AD9204的数据手册中推荐使用全差分放大器ADA4938来作为输入驱动,并且将ADC的Vcm输出连接到ADA4938的共模设置引脚。


    问题一:

    1、AD9204的共模输出电压Vcm是不是只有0.9V?(数据手册中没有给出该参数)

    2、ADA4938的输出共模电压最低只能设置到1.1V(高于0.9V)。

    所以如果使用数据手册中推荐的电路连接方式(ADA4938使用AD9204提供的共模电压Vcm),是不是存在问题?

    问题二:

    如果不使用ADC输出的共模电压,使用外部1.3V电压作为ADA4938的共模设置电压…

  • RE: ADA4932/38 recommended RG and RF

    Hi JinoL,

    Thanks for your comments. I have one more query on ADA4938. 

    I have configured the ADA4938 in Differential to single-ended and single-ended to differential configuration and observed the noise floor. I have used the ADA938 evaluation board from…

  • Recommended ADC driver and clock distribution devices for the AD9645

    What are the recommended ADC driver and clock distribution devices?

     

    Companion products are dependent on the configuration of the signal chain.  For
    differential RF or IF paths, we recommend the ultra-low distortion ADL5562
    amplifier…
  • Recommended ADC driver and clock distribution devices

    What are the recommended ADC driver and clock distribution devices?

     

    Companion products are dependent on the configuration of the signal chain.  For
    differential RF or IF paths, we recommend the ultra-low distortion ADL5562
    amplifier…
  • RE: AD9650: VCM pin

    Hello,

    It would appear that you have an oscillation in your circuit.  Questions:

    1) Is the VCM decoupled with 0.1 uF to AGND?

    2) Is your circuit exactly the same as what is shown in figure 79..............including component values .  If not how does…

  • RE: Correct layout of ADA4937-2

    Hi Eric,

    1. Yes, as much as possible there should be no ground and power planes in the pcb area where RF, RG and summing nodes are located. This means that no ground and power planes should be in that area from layers 2 to 8 of your pcb. This is to ensure…

  • RE: ADA4938 common mode setting

    Hello Julian!

    Two options:

    1. Remove R15(2k87) and set R14 to 3k9. With the 10k input impedance of the ADA4938 and AVDD of 1.8V, you will expect a VOCM of 1.295V. or

    2. Implement a resistor divider setting VOCM as an ideal voltage source, means that…

  • How to change the biasing level (1.5V) of the ADL5375-15 using active level shifting with appropriate filter design?

    I want to shift the biasing level of the ADL5375-15 using the active level shifting circuit. In which I am planing to use a ADA4938-2 diff amplifier to shift the level. After the amplifier I want to introduce a BB filter before the modulator.

    Please…

  • AD9265前端设计

    做一个1到30MHz的射频采样,选用AD9265-80,在它前端VGA选用AD602,驱动器选用ADA4938-2不知道可行吗,第一次做AD电路心里没底……