Bandgap Circuit PVT-Independent Current Generation
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Solution Overview
Problem
Electronic devices face instability in reference current generation due to process, voltage, and temperature variations, leading to resource consumption issues and incompatibility with low voltage domains.
Innovation Solution
A PVT-independent reference current is generated in a low voltage domain using a bandgap circuit with trimming circuitry, combining proportional-to-absolute-temperature and complementary-to-absolute-temperature currents to cancel out temperature variations, and utilizing a low potential voltage signal to reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional reference current generation circuitry is used, then reference current is generated, but the current deviates from target magnitude due to PVT variations
Solution Approach 1:
The patent changes the operating parameters by using a bandgap voltage reference (temperature-independent) combined with a PTAT current generator to create a reference current that compensates for PVT variations. The circuit transforms the temperature-dependent behavior of conventional references into a stable, compensated output by combining multiple current paths with opposite temperature coefficients.
Solution Approach 2:
The patent creates a composite reference current by combining multiple current generators: a bandgap voltage reference path and a PTAT current path. These composite current paths are summed to produce a reference current that has both the stability of the bandgap reference and the temperature compensation of the PTAT component, achieving PVT independence.
2Reliability
If resource-intensive elements are used to generate reference current, then current stability is improved, but device space and power consumption increase
Solution Approach 1:
The patent implements self-service by having the reference current generation circuit draw power from the low voltage domain itself rather than requiring external high-power supplies. The circuit uses locally available low-voltage power rails and generates its own compensated reference current, eliminating the need for resource-intensive external regulation and reducing overall power consumption.
Solution Approach 2:
The patent changes the power supply parameters by operating the entire reference current generation circuit from low voltage domain power rails instead of high-voltage supplies. This parameter change reduces power consumption while maintaining stability through the bandgap-PTAT compensation mechanism, achieving both low power and high reliability.
3Quantity of substance
If high voltage domain is used for reference current generation, then sufficient current magnitude is achieved, but compatibility with low voltage domains is lost
Solution Approach 1:
The patent transitions from a high-voltage domain approach to a low-voltage domain implementation by restructuring the reference current generation circuit. The circuit achieves sufficient current magnitude through efficient low-voltage circuit design and compensation techniques, enabling the reference current to be directly used in low voltage domains without voltage level conversion.
Solution Approach 2:
The patent creates a universal reference current source that operates effectively in low voltage domains while maintaining compatibility with various circuit requirements. The bandgap-PTAT compensated circuit provides a multi-functional solution that delivers both temperature stability and adequate current magnitude within the low voltage domain, serving multiple purposes without requiring high-voltage infrastructure.
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 provides a stable, resource-efficient reference current that is independent of PVT variations, compatible with low voltage domains, and reduces power consumption by eliminating the need for resource-intensive elements.
Implementation Method 1
A PVT-independent reference current is generated in a low voltage domain using a bandgap circuit with trimming circuitry, combining proportional-to-absolute-temperature and complementary-to-absolute-temperature currents to cancel out temperature variations
Data Source
AI summary
Systems and devices are provided for generating a process, voltage, temperature (PVT)-independent reference current for a relatively low voltage domain. An apparatus may include a bandgap circuit that outputs a bandgap voltage and a first proportion-to-absolute temperature (PTAT) current. The apparatus may also include trimming circuitry that outputs a reference a voltage based at least in part on the bandgap voltage. Further, the apparatus may include reference current generation circuitry. In particular, the reference current generation circuitry may include a complementary-to-absolute-temperature (CTAT) current generation portion that generates a CTAT current based on the reference voltage as well as a PTAT current tuning portion that tunes a received first PTAT current to generate a second PTAT current. In addition, the CTAT current generation portion may include a variation-independent reference current generation portion that generates a reference current based on the CTAT current and the second PTAT current.