Dual LDO Voltage Tracking With Overvoltage De-Tracking
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Solution Overview
Problem
Conventional dual LDO voltage regulators for automotive applications often require external ICs for voltage tracking, increasing cost and space, and lack efficient overvoltage protection mechanisms, which can negatively impact the auxiliary voltage regulator.
Innovation Solution
A dual LDO voltage regulator with independent output voltage selection and selective voltage tracking capabilities, where tracking mode is automatically initiated only when input values for both regulators are the same, and overvoltage events trigger independent operation to avoid negative impacts on the auxiliary regulator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If external ICs are used for voltage tracking in dual LDO regulators, then voltage tracking capability is provided, but cost and space increase
Solution Approach 1:
The patent combines the voltage tracking control logic directly into the dual LDO regulator IC itself, merging multiple functions (voltage regulation and voltage tracking control) into a single integrated device. This eliminates the need for external tracking ICs while providing both voltage regulation and selective tracking capability, thereby reducing cost and space without sacrificing adaptability.
Solution Approach 2:
The dual LDO regulator is designed with multi-functionality, capable of operating in both independent voltage regulation mode and voltage tracking mode. The control logic monitors configuration inputs and automatically switches between modes, making the device universally applicable to different application scenarios without requiring separate external components for each function.
2Reliability
If voltage tracking mode is continuously enabled, then voltage signal integrity is maintained, but auxiliary regulator can be negatively impacted by overvoltage events
Solution Approach 1:
The control logic continuously monitors the main regulator's output voltage and configuration inputs, providing feedback to determine whether to enable or disable voltage tracking mode. When overvoltage conditions are detected or when configuration indicates independent operation is needed, the control logic automatically disables tracking, preventing overvoltage damage to the auxiliary regulator while maintaining voltage signal integrity during normal operation.
Solution Approach 2:
The voltage tracking mode is made dynamic rather than static - it can be automatically enabled or disabled based on real-time operating conditions and configuration inputs. This dynamic switching capability allows the system to adapt to changing conditions, maintaining tracking when beneficial for voltage integrity while disabling it when overvoltage protection is needed for the auxiliary regulator.
3Adaptability or versatility
If independent output voltage selection is provided for both LDOs, then flexibility is increased, but voltage tracking operation becomes more complex to control
Solution Approach 1:
The control logic automatically determines whether to enable voltage tracking mode by monitoring the configuration inputs and output voltage settings of both LDOs. The system self-manages the tracking mode activation without requiring external control signals or complex external circuitry, thereby providing flexible independent voltage selection while keeping the control mechanism internally managed and relatively simple.
Data Source
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AI summary
A multi-output voltage regulator circuit (10), comprises: - at least one first voltage regulator (LDO1) having a first output voltage selection pin set (SEL1_LDO1, SEL2_LDO1, SEL3_LDO1) and configured produce a first output voltage (OUT_LDO1, Vo1) which is a function of a first digital signal received at the first output voltage selection pin set (SEL1_LDO1, SEL2_LDO1, SEL3_LDO1), and - at least one second voltage regulator (LDO2) having a second output voltage selection pin set (SEL1_LDO2, SEL2_LDO2, SEL3_LDO2) and configured to produce a second output voltage (OUT_LDO2, Vo2) which is a function of a second digital signal received at the second output voltage selection pin set (SEL1_LDO2, SEL2_LDO2, SEL3_LDO2). The first (LDO1) and second (LDO2) voltage regulators are operable in a voltage tracking mode with the output voltage (OUT_LDO2, Vo2) of the second voltage regulator (LDO2) tracking the output voltage (OUT_LDO1, Vo1) of the first voltage regulator (LDO1) when the digital signals received at the selection pin sets (SEL1_LDO1, SEL2_LDO1, SEL3_LDO1 and SEL1_LDO2, SEL2_LDO2, SEL3_LDO2) having a same digital value. An overvoltage sensor is provided to detect overvoltage events occurring at the at least one first voltage regulator (LDO1, Vo1) and control circuitry coupled to the overvoltage sensor is configured to avoid operation in the voltage tracking mode as a result of an overvoltage event detected at the first voltage regulator (LDO1.