Amplifier Configuration for Load-Line Enhancement

A system for load-line enhancement using amplifier reconfiguration, the system comprising:

• an amplifier including:
• a plus array of transistors coupled to a plus amplifier node and a plus input node, the plus array of transistors including multiple plus transistor stacks;
• a minus array of transistors coupled to a minus amplifier node and a minus input node, the minus array of transistors including multiple minus transistor stacks;
• at least one inductor coupled between the plus amplifier node and the minus amplifier node, the at least one inductor including an inter-inductor node;
• and
• configuration means for configuring the amplifier into different amplifier configurations;
• and
• control means for controlling the configuration means to adjust an effective impedance of a load line of the amplifier, the control means coupled to the configuration means.

A method for amplifier configuration for load-line enhancement, the method comprising:

• configuring an inductor power switch that selectively couples an inter-inductor node of at least one inductor to a supply voltage;
• configuring a power switch that selectively couples at least one amplifier node to another supply voltage, the at least one amplifier node disposed between the at least one inductor and at least one amplifier transistor;
• operating an amplifier in a first amplifier configuration in which the inductor power switch connects the inter-inductor node to the supply voltage having a second supply voltage level and the power switch is disconnected from the other supply voltage;
• and
• operating the amplifier in a second amplifier configuration in which the inductor power switch is disconnected from the supply voltage and the power switch connects the at least one amplifier node to the other supply voltage having the second supply voltage level.

An apparatus comprising:

• a differential amplifier including:
• a pair of input transistors coupled to an equipotential node, the pair of input transistors configured to receive a differential input signal;
• a pair of amplifier transistors respectively coupled in series with the pair of input transistors, the pair of amplifier transistors configured to amplify the differential input signal, the pair of amplifier transistors having a load line with a first impedance in conjunction with the pair of input transistors in accordance with a first amplifier configuration;
• amplifier configuration circuitry coupled to the pair of amplifier transistors;
• and
• amplifier configuration control circuitry coupled to the amplifier configuration circuitry, the amplifier configuration control circuitry configured to use the amplifier configuration circuitry to institute one or more other amplifier configurations that respectively correspond to the load line of the pair of amplifier transistors having one or more other impedances by reconfiguring current flow in the differential amplifier.