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.
Part Number: OPA356-Q1
Our customer are considering that this device can drive coaxial cable at the following input conditions.
- Vin_pp=1Vpp @Vdd=3.3V
- Vcm=+1.5V (+/-0.5V=1Vpp)
If it is not possible to use this device at the above condition for cable driver, please give us some other device that you recommend.
(We are considering OPA355 and OPA354 as well.)
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to Sean Cashin:
In reply to K.Hamamoto:
Thank you for your support.
For those devices what we found, do you think the slew rate is enough at the following condition?
- Fsig = 125MHz (Max) : Sin wave
- Vout_pp = 1.5Vpp (Max)
Because OPA355 and OPA356 has ability 300V/us of slew rate. However for the above condition, I think the slew rate should be more than 600V/us. What do you think?
Is my understanding correct? (dt/dV = PI * Fsig * Vp = PI * 125[MHz] * 1.5Vpp = 589V/us)
Yes, your understanding is correct. The OPA355 and 356 will be slew rate limited under this condition. The slew rate is what causes the amplifier's large signal bandwidth to be less than its small signal bandwidth. To determine whether or not an amplifier can drive a coaxial cable at a desired signal voltage, just check to see how well it can drive a load of Rsig+Zcharacteristic, or in this case 50+50=100ohms. This is limited by the amplifier's linear current output rating and the signal voltage.
In reply to hasmukh kabariya:
I understood. And I confirmed the behavior at the 50+50 ohm capability with TINA-TI.
It looks the output is little bit smaller than I expected. However as you mentioned I think it is caused by slew rate.
Is there any other recommended device?
You could try a CFA buffer like BUF602. The simulation results look promising.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.