Incorrect gain of AD835 as a Voltage Controlled Amplifier

Discussion in 'Analog & Mixed-Signal Design' started by Ngô Đình Nhân, Jan 16, 2019.

  1. Ngô Đình Nhân

    Thread Starter Member

    Jan 8, 2017
    Hi all
    I configured a AD835 as a voltage controlled amplifer which was same to its datasheet (attached file).

    My test condition:
    Schemes: same to Fig.21
    Vin (pin Y1): 100 mVpp, f = 10MHz
    Vg (pin X1): 0.5VDC
    Output signal was measured at pin 5 (pin W) by an oscilloscope.

    Measurement results:
    Output signal = 380mVpp

    So, it indicates that gain should be Vout/vin = 380/100 = 3.8.

    However, in its datasheet, this value should be 2.

    I am very confused by this.

    Does anyone, have experience with AD835, help me to clear this problem ?

    thanks in advanced
    Last edited: Jan 16, 2019