Reference Voltage Pre-Settling Circuit for Fast OP-Amp Wake-Up
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Solution Overview
Problem
Existing reference voltage generators in shrinking semiconductor devices face challenges in achieving fast power-up times and reducing power consumption due to slow OP-amp output settling times, especially when dealing with heavy RC loads.
Innovation Solution
The implementation of an OP-amp output pre-settling scheme in voltage generator circuits, which includes a pre-settling circuit that actively settles the OP-amp output to a threshold drop from power before stabilization, and a self-control scheme for power saving and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a traditional voltage generator circuit is used, then the circuit structure is simple, but the OP-amp output settling time is slow
Solution Approach 1:
The patent implements a pre-settling circuit that actively settles the OP-amp output voltage to a threshold drop from the power voltage before the main stabilization process begins. This preliminary action reduces the settling time by pre-positioning the output voltage close to its final value, avoiding the slow natural settling of the OP-amp with heavy RC loads.
Solution Approach 2:
The patent introduces a pre-settling circuit as an intermediary component between the power supply and the main voltage generator circuit. This intermediary circuit actively manages the initial voltage settling, mediating the transition from power-up to stable operation and reducing the burden on the main OP-amp.
2Loss of time
If the OP-amp output settling time is reduced, then the power-up time is shortened, but the power consumption increases
Solution Approach 1:
The patent employs a self-control scheme that activates the pre-settling circuit only during the power-up phase when settling is needed, and deactivates it during normal operation. This periodic action reduces power consumption by limiting the operation of power-intensive settling components to only when necessary, rather than maintaining them continuously.
Solution Approach 2:
The patent implements a self-control scheme using feedback mechanisms to monitor the voltage settling status and automatically control the pre-settling circuit. The feedback detects when the output voltage has settled to the threshold level and turns off the pre-settling circuit, optimizing the balance between settling speed and power consumption without manual intervention.
3Speed
If the pre-settling circuit is continuously active, then the settling speed is maintained, but the power consumption increases
Solution Approach 1:
The pre-settling circuit is designed to operate periodically rather than continuously, being activated only during power-up events when settling is required and deactivated during normal operation. This periodic operation maintains settling performance when needed while dramatically reducing average power consumption compared to continuous operation.
Solution Approach 2:
The self-control scheme enables the pre-settling circuit to manage its own operation based on system conditions. The feedback mechanism allows the circuit to automatically activate when settling is needed and deactivate when stable, making the system self-regulating and optimizing the trade-off between settling speed and power consumption without external control.
Data Source
AI summary
A reference voltage generator includes an input terminal configured to receive an enable signal and an output terminal configured to provide an output signal. A voltage generator circuit is arranged to generate a first output voltage signal, and a pre-settling circuit is arranged to generate a second output voltage. The pre-settling circuit is configured to provide the second output voltage signal at the output terminal in response to the enable signal received at the input terminal, and following a first time period provide the first output voltage at the output terminal.