Voltage Reference Circuit With PTAT-CTAT Temperature Compensation
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Solution Overview
Problem
The miniaturization of integrated circuits poses challenges in achieving stable reference voltages with minimal temperature dependence, as existing design and manufacturing processes struggle to compensate for temperature variations effectively.
Innovation Solution
A voltage reference circuit utilizing stacked gate devices with temperature-sensitive cascode structures and trimming circuits to generate a reference voltage with a temperature coefficient close to zero, employing PTAT and CTAT schemes to compensate for temperature changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If integrated circuits are miniaturized to increase functionality and operating speed, then device density and performance are improved, but temperature stability and reference voltage reliability deteriorate
Solution Approach 1:
The reference voltage generation is divided into multiple independent temperature compensation paths: a PTAT (proportional to absolute temperature) current path and a CTAT (complementary to absolute temperature) voltage path. These segmented paths independently compensate for temperature effects, allowing the miniaturized circuit to maintain reference voltage stability despite reduced size and increased operating speeds.
Solution Approach 2:
The invention dynamically adjusts circuit parameters through temperature-dependent current and voltage relationships. By utilizing the PTAT current (which increases with temperature) to compensate for the CTAT voltage (which decreases with temperature), the system maintains a stable reference voltage output across temperature variations, resolving the reliability issue in miniaturized high-speed circuits.
2Ease of manufacture
If standard design and manufacturing processes are used for miniaturized circuits, then manufacturing efficiency is maintained, but temperature compensation precision deteriorates
Solution Approach 1:
The circuit employs inherent temperature feedback mechanisms where the PTAT current automatically increases with temperature to compensate for the decreasing CTAT voltage. This feedback-based approach achieves precise temperature compensation without requiring complex external control systems, maintaining manufacturing efficiency while improving temperature compensation precision in miniaturized circuits.
3Reliability
If temperature compensation circuits are added to achieve stable reference voltages, then reference voltage stability is improved, but circuit complexity increases
Solution Approach 1:
The invention merges the temperature sensing and compensation functions into the existing reference voltage generation circuitry. The PTAT current path and CTAT voltage path are integrated such that they work together to produce a stable reference voltage output, achieving temperature compensation without adding significant circuit complexity to the miniaturized device.
Data Source
AI summary
An integrated circuit includes a first and second temperature-sensitive device, and a trimming circuit. The first temperature-sensitive device is configured to set a first bias current which monotonically increases in accordance with an absolute temperature of the integrated circuit, and to generate a first voltage based on the first bias current. The second temperature-sensitive device is configured to generate a second voltage, and to set a reference voltage at an output terminal of the integrated circuit. The trimming circuit is coupled to the second temperature-sensitive device, and configured to receive a trimming code signal. The second voltage monotonically decreases in accordance with the absolute temperature of the integrated circuit. The reference voltage is equal to a sum of the first voltage and the second voltage.