Self-Biased Amplifier Bias Switching for Low-Power Standby

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing self-biased amplifier circuits face challenges in achieving low power consumption without compromising circuit performance and compactness, particularly due to the need for additional switches that degrade performance and increase area.

Innovation Solution

A self-biased amplifier circuit design with complementary input transistors and bias transistors, utilizing transistor switches to control the circuit between active and standby modes, minimizing current flow through the switches and reducing their size to maintain performance and compactness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If additional switch(es) are added to shut down the circuit when not needed, then power consumption is reduced, but circuit performance degrades and area increases

Engineering Contradiction:
Improvepower consumptionVSAvoidcircuit performance
Core Design Contradiction:
Use of energy by stationary objectVSReliability

Solution Approach 1:

The circuit uses its own output signal to control the switching of bias currents through feedback to the bias transistor gates. The output node voltage directly modulates the bias transistors, enabling the circuit to automatically regulate its own power consumption without external control switches, thus avoiding performance degradation from additional switching components

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The circuit dynamically changes the bias current parameter based on operational needs. By modulating the gate voltages of bias transistors with the output signal, the circuit adjusts bias current levels to match activity requirements, reducing power consumption during low-activity periods while maintaining full performance when needed

Inventive Principle:
Principle #35Parameter changes

2Use of energy by stationary object

If additional switch(es) are added to shut down the circuit when not needed, then power consumption is reduced, but circuit area increases

Engineering Contradiction:
Improvepower consumptionVSAvoidcircuit area
Core Design Contradiction:
Use of energy by stationary objectVSArea of stationary object

Solution Approach 1:

The output signal serves multiple functions: it provides the amplified output signal and simultaneously acts as the control signal for power management by feeding back to modulate bias transistor gates. This multi-functionality eliminates the need for separate control switches, reducing circuit area while achieving power consumption reduction

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The circuit generates its own control signal from the output node to regulate its bias currents, eliminating the need for external control switches. This self-service approach reduces the number of components and overall circuit area while maintaining the ability to reduce power consumption

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4391370B1A self-biased amplifier circuit and a method for controlling a self-biased amplifier circuit
Publication Date: 2025.07.23 INTERUNIVERSITAIR MICRO ELECTRONICS CENT (IMEC VZW)
  • EP4391370B1 patent drawingFigure 1~2
  • EP4391370B1 patent drawingFigure 3a~3b
  • EP4391370B1 patent drawingFigure 4a~4b

AI summary

A self-biased amplifier circuit (100; 200), comprises: an input, wherein the input comprises input transistors (110, 112, 114, 116; 210, 212, 214, 216) forming inverters; bias transistors (118, 120, 122, 124; 218, 222), wherein a source of each input transistor (110, 112, 114, 116; 210, 212, 214, 216) is connected to a drain of a bias transistor (118, 120, 122, 124; 218, 222) for providing a bias current to the inverters; an output connected to a first output node (106; 206) and/or a second output node (108; 208); and pairs of transistor switches (126, 128; 226, 228) connected between the first (106; 206) or the second output node (108; 208) and a respective gate of the bias transistors (118, 120, 122, 124; 218, 222), wherein the pairs of transistor switches (126, 128; 226, 228) are configured to control the self-biased amplifier circuit (100; 200) to assume an active mode or a standby mode.