Low Power Reference Current Generator Using High-Impedance Resistive Element
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Solution Overview
Problem
Current reference current generators in integrated circuits consume excessive power due to the use of saturated transistors and small resistors, making them unsuitable for battery-powered devices that require ultra-low power consumption while maintaining temperature compensation.
Innovation Solution
A new reference current generator circuit that uses a voltage difference generator to supply two closely separated voltages across a high-impedance resistive element, reducing power consumption by applying a small voltage difference across a large resistor, implemented using a series-connected stack of diode-connected transistors and buffer amplifiers to achieve temperature compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If saturated transistors and small resistors are used in reference current generators, then temperature compensation is achieved, but power consumption increases significantly
Solution Approach 1:
The patent changes the operating parameters by using transistors in the linear (triode) region instead of saturation region, and by using large resistors instead of small resistors. This fundamental parameter change allows the circuit to achieve temperature compensation through different physical mechanisms while consuming significantly less power (nanoamp range vs microamp range).
Solution Approach 2:
The patent inverts the conventional approach by using large resistors (megaohm range) instead of small resistors, and linear region transistors instead of saturated transistors. This inversion of design parameters enables ultra-low power operation while maintaining temperature stability through alternative circuit topologies involving current mirrors and voltage references.
2Power
If a large voltage is applied across a small resistor to generate reference current, then sufficient current is generated, but power consumption becomes excessive
Solution Approach 1:
The patent fundamentally changes the electrical parameters by using large resistance values (megaohm range) and small voltage differences (millivolt range) instead of small resistance and large voltage. This parameter transformation enables the generation of nanoamp-level reference currents with power consumption reduced by factors of 10-1000 compared to conventional designs.
3Reliability
If conventional reference current generator topologies are used, then temperature insensitivity is achieved, but the circuit draws microamp currents exceeding battery-powered device limits
Solution Approach 1:
The patent employs parameter changes by operating transistors in the linear region with very small drain-source voltages and using megaohm-range resistors, thereby reducing current draw to nanoamp levels while maintaining temperature compensation through carefully designed current mirror circuits and voltage references.
Solution Approach 2:
The patent inverts conventional design practices by using large resistors and linear region transistors with minimal voltage drops, achieving ultra-low current consumption (nanoamps) while maintaining temperature stability through alternative circuit mechanisms including matched transistor pairs and precision voltage references.
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 solution achieves a significant reduction in power consumption, typically by 10-1000 times less than existing generators, while maintaining excellent temperature sensitivity, suitable for ultra-low power integrated circuits with nanoamp current budgets.
Implementation Method 1
The resistive element is adapted to generate a reference current that is a function of the third voltage and the fourth voltage
Data Source
AI summary
An improved reference current generator is provided. A voltage difference generator generates two voltages that are separated by a relatively small electrical potential. The two closely separated voltages are applied across a resistive element with relatively large impedance value resulting in a small and stable reference current. The result is a power efficient, temperature compensated reference current generator.