E-design
Advanced Member level 5
We were looking at an amplifier/booster to complement our current lab amplifiers and will be able to drive 20 Vpp into 50 Ω. We looked at doing a design using the TI THS3091, which has a ±250 mA capability and frequency response over 200 MHz. This will meet the 20 Vpp requirement perfectly when operating of a ±15 V supply.
We happen to see a module **broken link removed** that seemed to incorporate this part at a very good price. There are numerous sellers offering this module, and we even found it on Alibaba.
I am very aware of fake/cloned parts used by manufacturers, but decided to get the module as the part can always be replaced with a proper Texas Instruments part.
Well, a few days ago, the module arrived from China, and I performed some basic tests on it in the lab.
1) It failed miserably to drive a 50 Ω load. While the open-circuit voltage could reach in excess of 20 Vpp, the loaded voltage with minimal distortion, was only about 5.6 Vpp!
2) Next I performed a bandwidth test and found it to be about 40 MHz, instead of the claimed 210 MHz.
So I messaged the seller, confronting him with all the test results. I received a reply that it was passed on to the engineer. It will be very interesting to hear his reply, since they actually refer to the TI datasheet specs on their listing.
We happen to see a module **broken link removed** that seemed to incorporate this part at a very good price. There are numerous sellers offering this module, and we even found it on Alibaba.
I am very aware of fake/cloned parts used by manufacturers, but decided to get the module as the part can always be replaced with a proper Texas Instruments part.
Well, a few days ago, the module arrived from China, and I performed some basic tests on it in the lab.
1) It failed miserably to drive a 50 Ω load. While the open-circuit voltage could reach in excess of 20 Vpp, the loaded voltage with minimal distortion, was only about 5.6 Vpp!
2) Next I performed a bandwidth test and found it to be about 40 MHz, instead of the claimed 210 MHz.
So I messaged the seller, confronting him with all the test results. I received a reply that it was passed on to the engineer. It will be very interesting to hear his reply, since they actually refer to the TI datasheet specs on their listing.