Hello, I have a question regarding operational amplifiers. Whenever I search for some datasheets of high gain and high-speed Op Amps ( BW higher than 50MHz), I mostly find that they are made of bipolar transistors rather than mosfet. Why is it so?
I've done some research and I've found that MOSFET is better than BJT when it comes to input impedance, noise immunity, and offset level, three characteristics that are very important to have an ideal opamp. Also, MOSFET gives more freedom in design since the transconductance and so the gain can be tuned by re-sizing the MOSFETs. If so, why are bipolar transistors widely used for OpAmp?
Thank you in advance for enlightening me on this subject
I've done some research and I've found that MOSFET is better than BJT when it comes to input impedance, noise immunity, and offset level, three characteristics that are very important to have an ideal opamp. Also, MOSFET gives more freedom in design since the transconductance and so the gain can be tuned by re-sizing the MOSFETs. If so, why are bipolar transistors widely used for OpAmp?
Thank you in advance for enlightening me on this subject