Current-Mirror Bleeder Circuitry for Stable Voltage Buses
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Solution Overview
Problem
Amplifier-based bleeder circuitry in electronic devices is large and power-consuming, especially when numerous power amplifiers are used, wasting power even when not actively bleeding current from voltage buses.
Innovation Solution
A current-mirror-based bleeder circuitry implementation using proportional PMOS and NMOS transistors in current mirrors to efficiently sink leakage currents, with a startup transistor to balance the circuit during device startup, reducing power consumption and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If amplifier-based bleeder circuitry is used to sink leakage currents, then voltage stability is improved, but power consumption increases and circuit size increases
Solution Approach 1:
The patent changes the operating parameters of the bleeder circuit by using transistors in saturation region with carefully selected W/L ratios to achieve the desired bleeder current. This allows precise control of power consumption while maintaining voltage stability, resolving the contradiction between stability and power usage.
Solution Approach 2:
The patent creates a simplified model of the power amplifier's leakage behavior using a single transistor with proportional dimensions. This model copies the essential leakage characteristics without requiring full amplifier circuits, reducing power consumption while maintaining effective voltage stabilization.
2Stability of the object's composition
If amplifier-based bleeder circuitry is used to sink leakage currents, then voltage stability is improved, but circuit size increases
Solution Approach 1:
The patent changes the structural parameters of the circuit by replacing complex amplifier-based bleeders with simple transistor pairs operating in saturation. This dramatically reduces the circuit area while maintaining voltage stability through proper transistor dimensioning and current mirror configuration.
Solution Approach 2:
The patent uses a simplified transistor model that copies only the necessary leakage-sinking function without the bulky amplifier circuitry. This model uses proportional transistor dimensions to represent multiple power amplifiers' leakage, achieving voltage stability with minimal area.
3Power
If numerous power amplifiers are used to provide large current, then current capability is improved, but bleeder circuitry size increases
Solution Approach 1:
The patent merges the bleeder function for multiple power amplifiers into a single unified circuit using current mirrors. The proportional transistor dimensions allow one bleeder circuit to handle leakage from many amplifiers simultaneously, reducing total bleeder area while maintaining support for high current capability.
Solution Approach 2:
The patent creates a scaled model where transistor dimensions are proportional to the number of power amplifiers. This single model circuit copies the aggregate leakage behavior of numerous amplifiers, enabling effective bleeder operation with minimal circuit area regardless of the number of power amplifiers used.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The current-mirror-based bleeder circuitry consumes less power and size, effectively maintaining bus voltage stability while minimizing power waste, using a small current to compensate for multiple leakage currents, and addressing startup issues with additional circuitry.
Implementation Method 1
A current-mirror-based bleeder circuitry implementation using proportional PMOS and NMOS transistors in current mirrors to efficiently sink leakage currents
Implementation Method 2
the one or more transistors may leak some current during some standby modes. For instance, the one or more transistors may leak switch-off currents (Ioff) when the one or more transistors are turned off
Data Source
AI summary
Devices and methods include voltage buses. The devices also include one or more power amplifiers coupled to the voltage bus. Each of the one or more power amplifiers include one or more transistors. The devices also include a model that is configured to emulate leakage from at least one of the one or more transistors. A current mirror with a first transistor coupled to the model and a second transistor coupled to the voltage bus. The current mirror is configure to draw charge from the voltage bus based at least in part on the emulated leakage from the model.