Waveform Shaping Circuit Without Diodes for Temperature-Stable Pulses
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Solution Overview
Problem
The existing waveform shaping circuits, which include diodes, suffer from temperature-dependent forward voltage fluctuations, causing the target constant voltage to vary with temperature, leading to unreliable output pulse signals.
Innovation Solution
A waveform shaping circuit design that replaces diodes with a switch circuit and a capacitor, using a switch control circuit to apply a target constant voltage during both high and low voltage periods, ensuring the output pulse signal's peak-to-peak voltage remains equivalent to the input's AC component voltage, with the voltage during these periods set at a temperature-independent target constant voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a diode is used in the waveform shaping circuit, then the circuit can set the voltage during high voltage period at a constant level, but the forward voltage of the diode fluctuates with temperature causing the target constant voltage to vary
Solution Approach 1:
The patent removes the diode from the waveform shaping circuit to eliminate the temperature-dependent forward voltage characteristic. Instead of using a diode to clamp the voltage, the invention employs a capacitor combined with a switch circuit that is controlled to apply or stop application of a target constant voltage based on the input signal levels, thereby achieving voltage shaping without temperature-sensitive components.
Solution Approach 2:
The invention changes the operating parameters by using a controlled switch to dynamically apply a target constant voltage rather than relying on the fixed forward voltage drop of a diode. The switch control circuit monitors the input signal and activates the switch to maintain the output voltage at the desired constant level during high voltage periods, making the system's voltage reference independent of temperature variations.
2Temperature
If a switch circuit with control circuit is used instead of diode, then temperature independence is achieved, but device complexity increases
Solution Approach 1:
The switch circuit serves multiple functions: it acts as a voltage clamp during high voltage periods, functions as a temperature-independent voltage reference, and works in conjunction with the capacitor to shape the waveform. The control circuit integrates the detection of input signal levels and the control of the switch operation, combining what would traditionally be separate functions into a unified system that achieves temperature independence.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration reliably shapes input pulse signals into output pulse signals with temperature-stable peak-to-peak voltage and constant voltage levels, reducing noise malfunctions and enhancing design flexibility by eliminating diode-related temperature fluctuations.
Implementation Method 1
a capacitor with one end connected to an input where an input pulse signal is inputted and another end connected to an output
Implementation Method 2
a switch circuit that includes a switch without including a diode, has one end connected to an output and has another end to which a target constant voltage is applied, applies, in a state where the switch is on, the target constant voltage to the output and stops, in a state where the switch is off, application of the target constant voltage to the output
Data Source
AI summary
A waveform shaping circuit is configured without including a diode that is affected by temperature. The waveform shaping circuit includes: a capacitor with one end into which a differential signal Vd0 is inputted and another end connected to an output; an impedance element that has one end connected to the other end of the capacitor and another end into which a target constant voltage is applied; a switch circuit that is constructed of a series circuit with an impedance element and a switch without including a diode, has one end connected to the output, and has another end into which the target constant voltage is applied; and a switch control circuit that shifts the switch into an on state during a low voltage period in an AC component of the differential signal and shifts the switch to an off state during a high voltage period of the AC component.