Reference Signal Generator Using PTAT CTAT High-Order Compensation
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Solution Overview
Problem
Conventional reference signal generators experience imprecision due to temperature variations, as the reference signal changes with temperature changes, affecting the accuracy of circuit systems.
Innovation Solution
A reference signal generator with a second and third order compensation mechanism, utilizing a feedback network, amplifier circuit, and adjustment circuits to generate a reference signal that is minimally affected by temperature changes, including a second order adjustment circuit with a third transistor and a third order adjustment circuit that adjusts the bias voltage based on temperature, to achieve precise temperature compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional reference signal generator uses a simple feedback network with resistors and transistors to generate a reference signal, then the device complexity is low, but the reference signal varies with temperature changes causing imprecision
Solution Approach 1:
The temperature compensation is divided into multiple independent stages: first-order compensation using basic CTAT/PTAT signals, second-order compensation using additional transistors and resistors, and third-order compensation using further adjustment circuits. Each stage addresses specific temperature coefficients independently, allowing the system to achieve high precision without requiring a completely complex redesign.
Solution Approach 2:
The patent extends the compensation from simple linear (first-order) temperature compensation to quadratic (second-order) and cubic (third-order) temperature compensation. This dimensional extension in the mathematical compensation model allows the reference signal to remain stable across wider temperature ranges by compensating for higher-order temperature coefficients that simple linear compensation cannot address.
2Measurement precision
If second order temperature compensation is applied to reduce reference signal variation, then the reference signal precision improves, but the device complexity increases due to additional adjustment circuits
Solution Approach 1:
The compensation circuits are designed to target specific temperature coefficients locally. The second-order adjustment circuit specifically addresses quadratic temperature variations, while the third-order circuit addresses cubic variations. Each circuit is optimized for its specific function rather than attempting comprehensive compensation in a single complex block, reducing overall complexity.
Solution Approach 2:
The bias voltage in the adjustment circuits is made dynamically adjustable based on temperature conditions. The third-order adjustment circuit dynamically modifies the bias voltage to compensate for temperature-induced variations, allowing the system to adapt to changing temperature conditions rather than requiring fixed complex circuitry for all possible scenarios.
3Measurement precision
If third order adjustment circuit is used to further compensate temperature effects, then the reference signal remains more accurate across temperature ranges, but the ease of manufacture decreases due to additional circuit components
Solution Approach 1:
The third-order adjustment circuit uses additional transistors and resistors that replicate the structural pattern of the second-order circuit. This modular copying approach allows for systematic manufacturing and testing procedures to be reused across different compensation stages, reducing the overall manufacturing complexity despite the increased component count.
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 proposed solution significantly reduces the variation of the reference signal within a temperature range, enhancing the precision of the system by ensuring the reference signal remains stable across temperature changes, with the third order compensation further refining the accuracy beyond second-order adjustments.
Implementation Method 1
the first transistor and the second transistor are configured to operably generate a proportional to absolute temperature (PTAT) signal and at least one complementary to absolute temperature (CTAT) signal according to at least one bandgap related to the first transistor and the second transistor
Implementation Method 2
the amplifier circuit is configured to operably and linearly superimpose the PTAT signal and the CTAT signal via the feedback network, so as to generate the reference signal
Implementation Method 3
the third transistor is controlled by a bias voltage, so as to generate an adjustment current for adjusting the reference signal, wherein the adjustment current is positively correlated with a temperature under test
Implementation Method 4
a third order adjustment circuit, which is configured to operably adjust the bias voltage according to the temperature under test, thus adjusting the adjustment current, and to thereby adjust the reference signal
Data Source
AI summary
A reference signal generator having high order temperature compensation includes: first and second transistors generating a proportional to absolute temperature (PTAT) signal and at least one complementary to absolute temperature (CTAT) signal according to at least one bandgap related to the first and second transistors; a feedback network coupled to the first and second transistors; an amplifier circuit configured to linearly superimpose the PTAT signal and the CTAT signals via the feedback network, to generate a reference signal; a second order adjustment circuit including a third transistor controlled by a bias voltage, to generate an adjustment current for adjusting the reference signal; and a third order adjustment circuit configured to adjust the bias voltage according to a temperature under test, for adjusting the adjustment current, to adjust the reference signal, such that a variation of the reference signal is smaller than a predetermined variation range within a temperature range.