A
Anonymous
Guest
About four years ago, I was looking at the noise performance of various front end arrangements, and it seemed that the transmitter also contributed to the noise level. When the TX Mosfet is disconnected from the circuit, rather than being just off, the noise was lower. This could do with being looked at again as there may be various reasons for this. e.g. the Mosfet mounting tab (drain) is connected to a heat sink which can act as an antenna for noise external to the circuit, or even on board sources such as unsynchronised 7660's or other psu inverters.
As to opamp data sheets, for PI front ends, the only sure method is to try one and see if it works. I have bought countless opamps on the basis of a good paper spec, only to find that it is useless in this application. Clean recovery after the flyback pulse is the main problem area.
Eric.
As to opamp data sheets, for PI front ends, the only sure method is to try one and see if it works. I have bought countless opamps on the basis of a good paper spec, only to find that it is useless in this application. Clean recovery after the flyback pulse is the main problem area.
Eric.