Resistor-Based Phase Interpolator for Low-Power Precise Timing
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Solution Overview
Problem
Conventional phase interpolators face challenges in achieving low power consumption and high performance due to the need for current sources and bias circuits, which lead to increased power consumption and startup delays, and struggle with balancing precision, circuit area, and power consumption.
Innovation Solution
A phase interpolator design that eliminates the need for current sources and bias circuits by using resistors to control charging and discharging currents, allowing operation with low voltage and reducing gate capacitance, while also improving Differential Non-Linearity (DNL) and Integral Non-Linearity (INL) through switch configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current sources and bias circuits are used to control charging and discharging currents, then the phase interpolator can achieve precise phase control, but the power consumption increases and startup delays occur
Solution Approach 1:
The patent extracts and removes the current source and bias circuit from the phase interpolator architecture. Instead of using active current sources, the invention employs passive resistors to control the charging and discharging currents of the capacitor, thereby eliminating the need for bias circuits and reducing power consumption while maintaining phase control functionality
Solution Approach 2:
The patent replaces expensive and power-consuming current sources with simple, low-cost resistors. The resistors serve as disposable, passive elements that control current flow without requiring complex biasing circuits, significantly reducing both power consumption and circuit complexity
2Measurement precision
If current sources and bias circuits are used to control charging and discharging currents, then the phase interpolator can achieve precise phase control, but startup delays occur due to bias circuit initialization
Solution Approach 1:
The patent extracts and removes the bias circuit from the phase interpolator architecture. Instead of using active current sources that require bias circuit initialization, the invention employs passive resistors to control the charging and discharging currents of the capacitor, thereby eliminating the need for bias circuits and reducing startup delays
3Use of energy by moving object
If MOS transistor gate length is increased to reduce charging/discharging current, then power consumption is reduced, but gate capacitance becomes larger leading to increased power consumption
Solution Approach 1:
The patent replaces the active MOS transistor-based current control mechanism with a passive resistor-based system. Instead of relying on MOS transistor dimensions (gate length and channel width) to control current, the invention uses resistors with specific resistance values to control the charging and discharging currents, avoiding the trade-off between current reduction and capacitance increase
Solution Approach 2:
The patent changes the control parameter from MOS transistor physical dimensions (gate length L and channel width W) to resistor resistance values. By using resistors with appropriately selected resistance values, the system can control charging/discharging currents without the conflicting effects of increased gate capacitance that occur when MOS transistor gate length is increased
4Use of energy by moving object
If channel width is reduced to reduce charging/discharging current, then current is reduced, but variation increases resulting in degraded performance
Solution Approach 1:
The patent replaces the active MOS transistor-based current control mechanism with a passive resistor-based system. Instead of relying on MOS transistor dimensions (gate length and channel width) to control current, the invention uses resistors with specific resistance values to control the charging and discharging currents, avoiding the trade-off between current reduction and capacitance increase
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
The solution enables low-voltage operation with reduced power consumption, faster startup times, and improved linearity, effectively balancing precision and circuit area considerations.
Implementation Method 1
a capacitor having one end coupled to the intermediate line
Implementation Method 2
Each circuit unit comprises: a resistor and a first path arranged in series between the intermediate line and the second line
Data Source
AI summary
During a period in which a first signal S1 and second signal S2 are both set to a first level, an initializing circuit initializes a capacitor voltage. Multiple circuit units are coupled in parallel between an intermediate line and a second line. An output circuit generates an output signal SOUT that changes level when the capacitor voltage crosses a predetermined threshold value VTH. Each circuit unit includes a resistor Rg and first path arranged in series between the intermediate and second lines and a second path parallel to the first path. The first path is configured to turn on when the first signal S1 is the second level and the corresponding bit of an input code is a first value. The second path is configured to turn on when the second signal S2 is the second level and the corresponding bit of the input code is a second value.