Time-Encoding Modulator Switching Between Active and Passive Filters
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Solution Overview
Problem
Existing signal modulators, such as sigma-delta modulators and time-encoding modulators, face challenges in achieving low power consumption while maintaining high quality signal processing, especially in applications requiring continuous but intermittent data reception, like voice command recognition in battery-powered devices.
Innovation Solution
A reconfigurable time-encoding modulator apparatus that operates in two modes: a high-quality mode with an active filter and a low-power mode with a passive filter, enabling selective power management by enabling or disabling operational amplifiers and using a switch network to alter signal paths, allowing for efficient power usage without compromising signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If operational amplifiers are enabled to provide high-quality signal processing, then signal quality is improved, but power consumption increases
Solution Approach 1:
The filter arrangement is made reconfigurable between active and passive states through switch control, allowing the system to dynamically adapt its power consumption and signal processing capability based on operational requirements. The switches enable or disable operational amplifiers and reconfigure signal paths to transform the filter from an active high-quality mode to a passive low-power mode.
Solution Approach 2:
The system changes the operational state of the filter arrangement by altering the configuration of switches, which transforms the filter characteristics from active (with operational amplifiers) to passive (without operational amplifiers). This parameter change enables the system to switch between high signal quality and low power consumption states.
2Ease of operation
If the modulator operates continuously to receive data at any time, then responsiveness is improved, but power consumption increases
Solution Approach 1:
The filter arrangement operates in periodic cycles, switching between active mode during periods when signal processing is needed and passive mode during idle periods. This periodic activation allows the system to maintain responsiveness when required while reducing power consumption during intervals when full processing capability is not needed.
Solution Approach 2:
The reconfigurable filter arrangement automatically adapts its own operational state based on signal conditions and power management requirements, enabling the system to self-regulate between high-performance and low-power modes without external intervention, thus maintaining responsiveness while managing power consumption.
3Use of energy by moving object
If operational amplifiers are disabled to reduce power consumption, then power usage is reduced, but signal processing quality deteriorates
Solution Approach 1:
The filter arrangement is segmented into functional components that can be independently controlled - specifically, the operational amplifiers can be disabled while the passive filter structure remains intact. This segmentation allows the system to reduce power consumption by disabling active components while maintaining basic signal filtering functionality through passive components.
Solution Approach 2:
The passive filter configuration serves as a simplified, lower-cost alternative to the active filter with operational amplifiers. While it provides reduced signal processing quality, it maintains adequate functionality for low-power operation, similar to using a simpler, less expensive solution when full performance is not required.
Data Source
AI summary
This application relates to time-encoding modulators (TEMs). A TEM receives an input signal (SIN) and outputs a time-encoded output signal (SOUT). A filter arrangement receives the input signal and also a feedback signal (SFB) from the TEM output, and generates a filtered signal (SFIL) based, at least in part, on the feedback signal. A comparator receives the filtered signal and outputs a time-encoded signal (SPWM) based at least in part on the filtered signal. The time encoding modulator is operable in a first mode with the filter arrangement configured as an active filter and in a second mode with the filter arrangement configured as a passive filter. The filter arrangement may include an op-amp, capacitance and switch network. In the first mode the op-amp is enabled, and coupled with the capacitance to provide the active filter. In the second mode the op-amp is disabled and the capacitance coupled to a signal path for the feedback signal to provide a passive filter.