Power-On Reset Circuit Gating for Stable Band-Gap Startup
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Solution Overview
Problem
The existing power-on reset circuits face errors due to the instability of the band-gap reference circuit during the power-on process, leading to unreliable chip startup.
Innovation Solution
A power-on reset circuit comprising a band-gap reference circuit, a current comparator, and a voltage comparison circuit, where the current comparator is powered only when both the power supply voltage and the band-gap reference circuit are stable, ensuring a controlled output of a reset signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the power-on reset circuit outputs a reset signal when the power supply voltage reaches a preset value, then the chip can start to work, but the band-gap reference circuit may not be stable yet causing errors and chip startup failure
Solution Approach 1:
The patent applies preliminary action by adding a stability detection mechanism that checks whether the band-gap reference circuit has stabilized before allowing the reset signal to be output. The control circuit detects the stability of the band-gap reference circuit in advance, and only when stability is confirmed does it enable the power-on reset circuit to output the reset signal. This ensures that the chip starts working only after the reference circuit is stable, preventing startup errors while maintaining efficient boot timing.
2Stability of the object's composition
If the band-gap reference circuit is used to provide stable voltage to the chip, then temperature influence on voltage is reduced, but the band-gap reference circuit takes time to stabilize during power-on causing delayed reset signal output
Solution Approach 1:
The patent implements feedback by creating a closed-loop control system where the control circuit continuously monitors the output of the band-gap reference circuit to detect its stability status. The control circuit receives feedback signals from the band-gap reference circuit, processes this information, and accordingly controls the timing of the reset signal output. This feedback mechanism allows the system to adapt to the actual stabilization time of the band-gap reference circuit, ensuring voltage stability is achieved while minimizing unnecessary delays in the power-on process.
Data Source
AI summary
A power-on reset circuit, including: a band-gap reference circuit, a current comparator, and a voltage comparison circuit powered by a voltage source; a first output terminal of the band-gap reference circuit connects to a control terminal of the current comparator; a first current input terminal and a second current input terminal of the current comparator receives a first current signal and a second current signal respectively, and an output terminal of the current comparator connects to a control terminal of the voltage comparison circuit; and a first input terminal of the voltage comparison circuit connects to the first output terminal of the band-gap reference circuit, a second input terminal thereof receives a signal indicating a voltage value of the voltage source, an output terminal thereof outputs a reset signal, thereby avoiding occurrence of an error caused by output of the reset signal when the reference generating circuit is unstable.