Voltage Pre-Regulator Bias Circuit for Stable Mid-Voltage Conversion
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Solution Overview
Problem
Existing voltage regulators face challenges in efficiently converting middle voltage ranges to safe operating areas for low voltage devices, particularly in protecting low voltage devices from high input voltages and maintaining precision and stability across a wide range of temperatures and input voltages.
Innovation Solution
A voltage pre-regulator system utilizing a bias circuit with balanced positive and negative feedback to amplify leakage current, coupled with a laterally diffused metal oxide semiconductor (LDMOS) transistor, generates a regulated voltage drop to convert middle voltage inputs to low voltage outputs, ensuring safe operation and high precision within a low voltage safe operating area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a voltage regulator uses low voltage devices to provide accuracy to the regulated output voltage, then measurement precision is improved, but the devices are vulnerable to damage from high input voltages
Solution Approach 1:
The patent introduces an intermediary protection circuit between the high input voltage and the low voltage devices. This circuit includes a first transistor that acts as a voltage clamp, limiting the voltage seen by subsequent low voltage devices to a safe level. The intermediary structure allows accurate low voltage devices to operate precisely while being protected from harmful high input voltages through the voltage-clamping action of the protection circuit.
2Stability of the object's composition
If a voltage regulator converts high input voltage to low output voltage using a controllable voltage drop, then the output voltage remains fixed, but power loss increases during conversion
Solution Approach 1:
The voltage conversion process is segmented into multiple stages rather than a single large voltage drop. The patent divides the conversion into: (1) a first conversion stage using a first transistor to drop voltage from input to intermediate level, and (2) a second conversion stage using a second transistor to drop from intermediate to final output level. This segmentation allows each stage to operate more efficiently, reducing overall power loss while maintaining stable output voltage through coordinated control of both transistors.
3Adaptability or versatility
If a voltage regulator operates across a wide range of input voltages and temperatures, then adaptability is improved, but maintaining precision and stability becomes more difficult
Solution Approach 1:
The patent implements feedback mechanisms to maintain output voltage precision across wide input voltage ranges and temperature variations. The protection circuit and voltage conversion stages use feedback control where the output voltage is monitored and compared to a reference, and the control transistors are adjusted accordingly to compensate for input variations and temperature drift, ensuring stable and precise output regardless of operating conditions.
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AI summary
A voltage pre-regulator can receive a variable voltage in a middle voltage range (e.g., dozens of volts) and provide a regulated voltage in a safe operating region of a low voltage device. The use of the voltage pre-regulator can allow circuits to use low voltage devices to perform additional regulation/conversion without fear of damage. The voltage pre-regulator disclosed herein can perform the voltage reduction and regulation functions of pre-regulation with commonly used transistor types because the disclosed circuits and method use a bias circuit. The bias circuit uses positive feedback so that no additional start-up circuitry is required. The positive feedback is controlled by negative feedback so that the pre-regulator is able to provide a regulated voltage that is stable over a range of input voltages and temperatures.