On-Die Thermal Sensor ADC Without Negative Reference Voltage
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Solution Overview
Problem
Conventional on-die thermal sensors in semiconductor memory devices require a negative reference voltage for integrating analog-digital converters, which complicates chip design and increases current consumption due to the need for additional circuitry to generate this voltage.
Innovation Solution
An integrating analog-digital converter that eliminates the need for a negative reference voltage by integrating the difference between a reference voltage and a comparing voltage, where the comparing voltage is higher than the reference voltage, and uses a counting unit to generate a digital code based on the voltage level, allowing for a more straightforward and efficient conversion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a negative reference voltage is used in the integrating analog-digital converter, then the conversion accuracy is improved, but the device complexity and current consumption increase due to additional voltage generation circuitry
Solution Approach 1:
The patent extracts and eliminates the negative voltage generation circuitry from the system by using a positive reference voltage instead. The integrating unit is modified to integrate the difference between a positive reference voltage and the comparing voltage, removing the need for negative voltage while maintaining conversion functionality.
Solution Approach 2:
The patent changes the voltage parameter from negative to positive. By using a positive reference voltage (Vref) instead of a negative reference voltage, the system achieves the same integration function without requiring additional voltage inversion circuitry, thereby reducing device complexity.
2Measurement precision
If a negative reference voltage is used in the integrating analog-digital converter, then the conversion accuracy is improved, but the current consumption increases due to additional voltage generation circuitry
Solution Approach 1:
The patent extracts and eliminates the negative voltage generation circuitry from the system by using a positive reference voltage instead. The integrating unit is modified to integrate the difference between a positive reference voltage and the comparing voltage, removing the need for negative voltage while maintaining conversion functionality.
3Speed
If a tracking analog-digital converter is used, then the conversion speed is improved, but the conversion accuracy deteriorates compared to integrating type
Solution Approach 1:
The patent implements feedback control in the integrating unit where the output voltage is continuously compared with the input comparing voltage. The integration process automatically adjusts the output based on the voltage difference, providing feedback that ensures both speed and accuracy in the conversion process.
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 solution enables the use of integrating analog-digital converters in on-die thermal sensors without the need for negative voltage generation, reducing chip size and current consumption, and making the technology more applicable to semiconductor memory devices.
Implementation Method 1
an operational amplifier integrating a difference between a reference voltage and a comparing voltage to output a second voltage increasing as time passes
Implementation Method 2
a comparator comparing the first voltage with the second voltage
Data Source
AI summary
An on-die thermal sensor includes an integrating analog-digital converter not requiring a negative reference voltage input. The on die thermal sensor includes a band gap unit, an integrating unit and a counting unit. The band gap unit senses a temperature to output a first voltage corresponding to the sensed temperature. The integrating unit integrates a difference between a reference voltage and a comparing voltage to output a second voltage wherein the comparing voltage has a voltage level higher than that of the reference voltage. The counting unit counts clocks of a clock signal input thereto until the second voltage reaches the first voltage, thereby outputting a thermal code corresponding to the voltage level of the first voltage.