Cascode
![](/Images/godic/202501/03/CascodeWithNegative0820.png")
![High-voltage stack](/Images/godic/202501/03/Cascode-voltage-ladder0821.png")
![Figure 2: BJT Cascode using ideal current sources for DC bias and large coupling capacitors to ground and to the AC signal source; capacitors are short circuits for AC](/Images/godic/202501/03/BJT_Cascode0821.png")
![Figure 3: MOSFET Cascode using ideal voltage sources for DC gate bias and a DC current source as active load. Since each MOSFET transistor has gate and source connected, this configuration is valid only for discrete 3-terminal components.](/Images/godic/202501/03/MOSFET_Cascode0821.png")
The cascode is a two-stage amplifier composed of a transconductance amplifier followed by a current buffer.
Compared to a single amplifier stage, this combination may have one or more of the following characteristics: higher input-output isolation, higher input impedance, high output impedance, higher gain or higher bandwidth.