N.N. Prokopenko, N.V. Kovbasjuk, A.I. Serebryakov
In modern microelectronics are used in broadband amplifiers сascode (BAC) channels of their own compensation capacity of the collector-base output transistor, implemented through non-inverting repeaters of the current. This architecture is used in various differential stages, active loads, current sources of reference and allows several once to improve the upper cutoff frequency BAC for cases where the capacity of the collector-base output transistor has a dominant influence on the upper cutoff frequency. Significant disadvantage of such BAC is that restrictions on the supply voltage, typical for SiGe processes, and restrictions on the use of the collector load resistor instead of resistive loads on the pnp transistor, its voltage gain is obtained by a small ( ).
This problem is solved in the scheme – increasing the limit values of the voltage gain for low-voltage power due to the compensation effect on the relatively low-impedance resistor collector load. Static mode of the scheme is set circuits offset potentials.
Architecture circuits of multi-channel compensation capacitance of the collector load transistor and the collector load resistor broaden representation of developers of analog circuits on how to improve the gain in cascode amplifiers.