Bandgap Reference Start-Up Circuit for Stable Voltage Generation
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Solution Overview
Problem
Existing bandgap reference voltage generation circuits in semiconductor devices often fail to stably generate and supply reference voltages during initial start-up operations due to changes in the driving environment such as supply voltage, process, and temperature variations.
Innovation Solution
A bandgap reference voltage generation circuit is designed with a start-up circuit that includes a beta-multiplier reference circuit and a comparator. The start-up circuit outputs a start-up signal when the supply voltage rises, activating the bandgap reference core circuit. The comparator ensures the start-up circuit terminates when the bandgap reference voltage reaches a target voltage, maintaining stability independent of environmental changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional bandgap reference voltage generation circuit is used, then the circuit structure is simple, but the circuit fails to stably generate reference voltage during start-up due to driving environment changes
Solution Approach 1:
The start-up circuit is activated before the main bandgap reference circuit to pre-charge capacitors and establish proper initial conditions. This preliminary action ensures that when the main circuit activates, all nodes are already at correct voltage levels, preventing start-up failures regardless of supply voltage rise time or temperature conditions.
Solution Approach 2:
The start-up circuit acts as an intermediary between the power supply and the main bandgap reference circuit. It conditions the power supply voltage and provides controlled activation signals to the main circuit, isolating the main circuit from direct exposure to varying supply conditions and ensuring stable operation.
2Reliability
If the start-up circuit operates continuously to ensure stable start-up, then start-up reliability is improved, but power consumption increases
Solution Approach 1:
The start-up circuit operates periodically rather than continuously. It activates briefly during power-up to establish initial conditions, then automatically deactivates once the main circuit is stable. This periodic operation provides necessary start-up support while minimizing power consumption during normal operation.
Solution Approach 2:
The start-up circuit includes feedback mechanisms that monitor the voltage levels at key nodes. When the main bandgap reference circuit reaches stable operating conditions, the feedback signals automatically shut down the start-up circuit, preventing continuous power consumption while ensuring reliable start-up completion.
Data Source
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AI summary
The present invention relates to a bandgap reference voltage generation circuit capable of stably generating a bandgap reference voltage by implementing a stable start-up operation regardless of changes in a driving environment. The bandgap reference voltage generation circuit, according to an embodiment, may comprise: a start-up circuit that outputs a start-up signal when a first power voltage rises; and a bandgap reference core circuit in which an operation is enabled in response to the start-up signal and that generates and outputs the bandgap reference voltage, wherein the start-up circuit may include: a beta-multiplier reference circuit including a cascode current mirror circuit that forms a first current path and a second current path between a first power line and a second power line; a start-up output unit that outputs the start-up signal in response to a voltage of an output node of the second current path; and a comparator that compares the bandgap reference voltage with a target voltage to disable the operation of the start-up circuit.