Voltage Regulator Transistor Thermal Management via Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voltage regulator circuit designs fail to adequately consider thermal issues, leading to increased operating temperatures and reduced reliability of pass devices, which limits the integration of voltage regulator circuits with other sensitive circuits on a single integrated circuit die.
Innovation Solution
The design incorporates a distributed group of individual, electrically parallel-interconnected pass transistors that are thermally segregated by spatially separating them on the integrated circuit die to reduce self-heating and allow for more even heat dissipation, enabling increased ambient temperature range and power dissipation capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single integrated pass transistor is used in the voltage regulator circuit, then the circuit integration is simplified, but the transistor operating temperature increases due to self-heating
Solution Approach 1:
The pass transistor is divided into multiple parallel-connected transistor devices distributed across the integrated circuit die. Each transistor handles a portion of the total current, distributing the power dissipation and reducing self-heating in each individual device while maintaining the required total power handling capability.
2Temperature
If multiple parallel transistors are used to reduce self-heating, then the transistor operating temperature decreases, but the device complexity and layout difficulty increase
Solution Approach 1:
Multiple parallel transistors are electrically connected and controlled by a single gate voltage, effectively merging their control functions. The control circuitry treats the parallel combination as a single equivalent transistor, simplifying the control architecture while achieving thermal management through physical distribution.
3Device complexity
If the pass transistor is fully integrated onto the die, then external discrete transistors and heat sinks are eliminated, but the maximum power dissipation capability is limited by die thermal constraints
Solution Approach 1:
The power dissipation load is segmented across multiple distributed transistor devices on the die. By spreading the power dissipation events across multiple locations rather than concentrating them in a single device, the local thermal density at any one point is reduced, enabling higher total power dissipation within the same die thermal constraints.
4Ease of manufacture
If conventional layout approaches are used, then the design process is simplified, but thermal issues and self-heating effects are not adequately addressed
Solution Approach 1:
Different regions of the integrated circuit die are utilized with specific functional assignments. The parallel transistors are placed in regions optimized for power handling and thermal dissipation, while other regions are reserved for sensitive analog circuitry. This spatial differentiation of functional requirements optimizes both thermal performance and circuit functionality.
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
This approach enhances the reliability and flexibility of voltage regulator circuits by reducing transistor operating temperatures, allowing for full integration without external discrete transistors and heat sinks, and enabling integration with thermally sensitive circuits.
Implementation Method 1
The pass device may be required to sustain a significant voltage drop while providing a significant output current. Such a voltage drop can lead to significant power dissipation by a pass device in the voltage regulator circuit, and corresponding self-heating consequences.
Implementation Method 2
The thermal segregation may be accomplished by spatially separating the transistors on an integrated circuit die, such as in cooler regions of the integrated circuit die, or away from die regions that are heat-sensitive.
Data Source
AI summary
Methods and apparatus to reduce localized transistor operating temperature increases in fully integrated voltage regulator circuits are provided. Transistor self-heating effects are reduced by dispersing heat more evenly over the integrated circuit die, via use of nested voltage regulator circuits and/or use of more than one transistor in a voltage regulator circuit pass device. An electrically parallel-connected group of multiple individual integrated transistors may be laid out across cooler areas of the integrated circuit die, such as in substantially linear sets or rings of devices near the outer die perimeter. Each transistor in the group may better disperse its own heat if it is thermally segregated from other self-heating devices, as through a minimum physical layout spacing. Transistor bias voltage mismatch tolerances, load currents, and routing resistances may interrelatedly determine the number of individual transistors needed in a group.