Voltage Reference Circuit for Safe ASIC Ramp-Up and Ramp-Down
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Solution Overview
Problem
Existing electrical circuits face challenges in ensuring safe ramp-up and ramp-down of regulated operating voltages, reference voltages, and reset signals for ASICs, particularly due to mutual dependencies between voltage reference generation and operating voltage generation, leading to potential undervoltage or overvoltage mis detections and malfunctions during ramp-up and ramp-down processes.
Innovation Solution
The proposed electrical circuit supplies the voltage reference circuit with a regulated operating voltage from a voltage regulator, which obtains its reference voltage from the voltage reference circuit, ensuring that the voltage regulator and voltage reference circuit do not prevent each other from ramping up, and includes a comparator and AND gate to evaluate the reset signal only when the operating voltage is sufficient, eliminating the need for a separate power-on reset circuit and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the voltage reference circuit is supplied with an unregulated operating voltage, then the circuit complexity is reduced, but the power supply rejection ratio deteriorates and voltage monitoring accuracy deteriorates
Solution Approach 1:
The voltage supply system is segmented into multiple regulated voltage domains. The voltage reference circuit is supplied with a first regulated operating voltage, while other circuits receive a second regulated operating voltage. This segmentation allows each circuit to operate with optimally regulated voltage, improving power supply rejection ratio without excessive complexity.
Solution Approach 2:
The patent changes the voltage regulation parameter by introducing multiple voltage regulators with different regulation levels. The first voltage regulator provides a highly regulated voltage for the voltage reference circuit, while the second voltage regulator provides a differently regulated voltage for other circuits. This parameter differentiation resolves the contradiction between complexity and power supply rejection ratio.
2Use of energy by moving object
If the voltage regulator and voltage reference circuit are mutually dependent, then power consumption is reduced, but the reliability deteriorates due to potential deadlocks during ramp-up and ramp-down
Solution Approach 1:
The system performs preliminary action by establishing a defined startup sequence where the voltage reference circuit is initialized first with a regulated operating voltage before the voltage regulator is fully activated. This preliminary initialization prevents deadlocks during ramp-up and ramp-down operations while maintaining power efficiency.
Solution Approach 2:
A first voltage regulator acts as an intermediary between the unregulated power supply and the voltage reference circuit. This intermediary provides a stable, regulated operating voltage to the voltage reference circuit during critical ramp-up and ramp-down transitions, preventing mutual dependency deadlocks while maintaining overall power efficiency.
3Reliability
If a separate power-on reset circuit is added to ensure safe operation, then the reliability improves, but the device complexity and power consumption worsen
Solution Approach 1:
The voltage regulator is designed with multi-functionality, serving both as a voltage regulation device and as a power-on reset source. The regulated operating voltage output from the voltage regulator directly enables the voltage reference circuit operation, eliminating the need for a separate power-on reset circuit while maintaining reliability during voltage transitions.
Solution Approach 2:
The power-on reset function is merged with the voltage regulation function. The first voltage regulator simultaneously performs voltage regulation and provides the power-on reset signal to the voltage reference circuit. This merging reduces device complexity and power consumption while maintaining safe operation during ramp-up and ramp-down.
4Reliability
If the voltage regulator regulates to a lower voltage to improve power supply rejection ratio, then the power supply rejection ratio improves, but the voltage reference circuit cannot reach its target value
Solution Approach 1:
The voltage regulation system operates dynamically with different regulation levels at different times. During startup, the voltage regulator provides a higher voltage to ensure the voltage reference circuit reaches its target value. During steady-state operation, it regulates to a lower voltage to improve power supply rejection ratio. This dynamic operation resolves the contradiction between accuracy and rejection ratio.
Solution Approach 2:
The system performs preliminary voltage regulation at a higher level to ensure the voltage reference circuit reaches its target value during startup. After the voltage reference circuit is properly initialized, the voltage regulator transitions to a lower regulation level to improve power supply rejection ratio. This preliminary high-voltage action ensures accuracy while subsequent low-voltage operation improves rejection ratio.
Data Source
AI summary
An electrical circuit for ensuring safe ramp-up and ramp-down of at least a regulated operating voltage, a reference voltage, and a reset signal for a consumer is described. The electrical circuit includes a voltage reference circuit and a voltage regulator. The voltage regulator is provided in order to furnish a regulated operating voltage, the voltage reference circuit is provided in order to be supplied with the regulated operating voltage furnished by the voltage regulator, and the voltage regulator is provided in order to obtain a reference voltage from the voltage reference circuit.