Time-Encoding Modulator With Switchable Active-Passive Filtering
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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 'always-on' functionality for voice commands and ultrasonic data transfer, where power efficiency and quality are crucial.
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, selectively enabling or disabling operational amplifiers to optimize power usage and signal processing quality based on operational needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If operational amplifiers are enabled to provide high-quality signal processing, then signal processing 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 performance characteristics based on operational requirements. The operational amplifier can be enabled or disabled to switch between high-quality active filtering and low-power passive filtering.
Solution Approach 2:
The system changes the operational state of the operational amplifier (enabled/disabled) to alter the filter arrangement's characteristics. This parameter change allows switching between active filter mode (high quality, high power) and passive filter mode (low quality, low power) to resolve the contradiction between signal processing quality and power consumption.
2Use of energy by moving object
If operational amplifiers are disabled to reduce power consumption, then power consumption is reduced, but signal processing quality deteriorates
Solution Approach 1:
The system dynamically switches between active and passive filter configurations based on power requirements. When power consumption needs to be reduced, the operational amplifier is disabled and the filter arrangement operates in passive mode, sacrificing some signal processing quality for lower power consumption.
Solution Approach 2:
By changing the operational state of the operational amplifier from enabled to disabled, the system transitions from active filter mode (high quality) to passive filter mode (low power), accepting a trade-off in signal processing quality to achieve power savings in always-on applications.
3Measurement precision
If an active filter is used, then signal processing quality is improved, but device complexity increases
Solution Approach 1:
The filter arrangement is designed to serve multiple functions: it can operate as an active filter when high signal processing quality is needed, and as a passive filter when power consumption is the priority. The same hardware components (operational amplifier, switches, resistors, capacitors) perform different functions based on their configuration state, reducing the need for separate dedicated circuits.
Solution Approach 2:
The filter arrangement's characteristics are made dynamic and reconfigurable rather than fixed. The operational amplifier and associated components can be enabled or disabled to switch between active and passive filter modes, allowing a single circuit to adapt to different performance requirements without requiring multiple separate filter circuits.
4Device complexity
If a passive filter is used, then device complexity is reduced, but signal processing quality deteriorates
Solution Approach 1:
The same filter arrangement components serve dual purposes: they can function as a passive filter for low-power operation or be reconfigured with the operational amplifier enabled to provide active filtering for high-quality signal processing. This multi-functionality eliminates the need for separate passive and active filter circuits.
Solution Approach 2:
The filter arrangement's performance characteristics are made changeable through control of the operational amplifier's operational state. By adjusting whether the operational amplifier is enabled or disabled, the system can transition between passive filter mode (simpler operation) and active filter mode (higher quality), allowing a single circuit to adapt to different quality requirements.
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 is coupled to a signal path for the feedback signal to provide a passive filter.