problem in driver circuit

Discussion in 'General Electronics Chat' started by qdhossain, Jul 30, 2008.

  1. qdhossain

    Thread Starter New Member

    Jul 30, 2008
    1
    0
    Hi!!

    I have made a driver circuit to drive a load is given in the following attachment file.But problem is when I increase the frequency of the input signal (from 100kHz~ 30MHz) ,the amplitude of the signal at the load is decrease.

    Could you please to tell me how can i solve this problem because I need a constant amplitude output at frequency from 100kHz to 30 MHz.

    With regards

    Himel Mahmud
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,634
    2,342
    Hello,

    I have taken a look at the data sheet and found a diagram for freq. / gain.
    How much gain do you expect?
    With a gain of 2 it should work upto 40 Mhz.
    With a gain of 5 it should work upto 10 Mhz.

    Greetings,
    Bertus
     
  3. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    At low frequencies, the load will appear mostly resistive - although the 2.5 Ohm resistors represent quite a hefty load.

    But the higher the input frequency, the more C1 and C2 will come into play to shunt the AC signal to ground, thus decreasing peak-to-peak signal levels.
     
  4. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    656
    Harmonic distortion is only specified down to 100 ohm load (see Fig. 21), at unity gain. This indicates to me that 100 ohms is about the minimum useable differential load.
    Your heavy load reduces loop gain, which reduces closed loop bandwidth. I think you are getting results which are to be expected.
     
Loading...