• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 48 subscribers
  • Views 392 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

analog signal bandwidth

Ilan Hazi
Prodigy 20 points
Other Parts Discussed in Thread: LMV881, OPA330

Hi,

I need to find differential op-amp that should drive analog signal into flex flat cable with length of 2 meter.

The analog signal is output with 128KHz clock. I found the two op-amp: LMV881 and OPA330. OPA330 seems more suitable but his GBWP is 380KHz whereas LMV381 has GBWP of 23MHz. How can I calculate the GBWP that I need for the analog signal? thanks ]

  • 0
    TI__Genius 12325 points

    The gain bandwidth product refers to the linear relationship between the bandwidth an amplifier is able to achieve at a certain gain. For example, an op amp with a gain bandwidth product of 10MHz and configured in a gain of 10, will achieve a bandwidth of 1MHz.

    Gain is relatively simple to calculate, Voltage gain = Vout / Vin. Determining the bandwidth needed may be more difficult. Assuming your clock signal is a square wave, you will need an op amp with a gain bandwidth product significantly higher than 128kHz to accurately reproduce this signal . This is because a square wave consists of a large number of high frequency odd order harmonics in addition to the fundamental.

    Furthermore, the amplifier's slew rate is a major consideration when reproducing a square wave. The slew rate is a measure of how rapidly the output voltage of the amplifier can change ( given in volts / time, most often volts / microsecond). This specification will determine how well the op amp can follow the transitions of your clock signal. 

    Given the above information, I do not think the OPA330 will have sufficient bandwidth and slew rate to reproduce your clock signal. The LMV881 is more likely a better option.