Analysis and Design of Analog Integrated Circuits 2.1 Single-transistor amplifiers One single transistor can be used as an amplifier,a source follower or a cascode.Moreover,gain boosting can be applied by a cascode,which is little more than a cascode combined with an amplifier. With two transistors two more configurations can be differential pair and the current mirror.Combined,they give rise to a full four-transistor differential voltage and current amplifier. 2019/9/3 UESTC-Luo PingAnalysis and Design of Analog Integrated Circuits 2019/9/3 4 One single transistor can be used as an amplifier, a source follower or a cascode. Moreover, gain boosting can be applied by a cascode, which is little more than a cascode combined with an amplifier. With two transistors two more configurations can be differential pair and the current mirror. Combined, they give rise to a full four-transistor differential voltage and current amplifier. UESTC – Luo Ping 2.1 Single-transistor amplifiers