problem in driver circuit

Thread Starter

qdhossain

Joined Jul 30, 2008
1
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
 

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bertus

Joined Apr 5, 2008
22,276
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
 

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SgtWookie

Joined Jul 17, 2007
22,230
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.
 

Ron H

Joined Apr 14, 2005
7,063
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.
 

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