Switching Driver Circuitry for Transducer Voltage Ripple Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional switching driver circuits face challenges in generating high output voltage ranges for transducers with high impedance loads, leading to large voltage ripple and unwanted Electromagnetic Interference (EMI), and require power boosting which results in inefficiencies.
Innovation Solution
A switching driver apparatus with a network of capacitors and switches that allows the output node to be switched between multiple voltage levels, using a controller to manage different switch states and supply nodes to achieve the desired output voltage range without large voltage changes, thereby reducing ripple and EMI.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the switching driver uses a large voltage difference between high and low switching voltages to achieve the desired output voltage range, then the output voltage range is sufficient, but the load current ripple and EMI increase significantly
Solution Approach 1:
The patent segments the voltage switching process by introducing intermediate voltage levels between the high and low switching voltages. Instead of directly switching between extreme voltage levels, the driver uses multiple capacitor nodes that provide stepped voltage transitions, thereby reducing the voltage change magnitude at each switching event and consequently reducing current ripple and EMI while still achieving the full output voltage range over the complete switching cycle.
Solution Approach 2:
The patent introduces capacitor nodes as intermediary elements between the high and low supply voltages. These capacitor nodes serve as intermediate voltage sources that allow the output to transition through multiple voltage levels rather than directly between extreme levels. This intermediary approach smooths the voltage transitions and reduces the harmful effects of large voltage changes on the load current and EMI.
2Power
If the switching driver generates high switching voltages to drive high impedance loads, then the required output power is achieved, but power losses increase due to voltage boosting requirements
Solution Approach 1:
The patent applies preliminary action by pre-charging capacitor nodes to intermediate voltage levels before they are needed for output switching. The capacitors are charged during specific phases of the switching cycle to prepare intermediate voltage levels in advance, eliminating the need for real-time voltage boosting when high output power is required. This pre-preparation of voltage levels reduces power losses by avoiding energy-intensive boosting operations during critical output phases.
3Ease of operation
If the switching driver switches between extreme high and low voltages to maximize output signal amplitude, then the driving capability for high impedance transducers is improved, but the ripple in load current increases
Solution Approach 1:
The patent segments the voltage transition path by introducing multiple intermediate capacitor nodes between the extreme high and low voltage levels. This segmentation allows the output to switch through a series of smaller voltage steps rather than making large direct jumps, thereby maintaining the full driving capability for high impedance transducers while significantly reducing the ripple in load current through smoother transitions.
Data Source
AI summary
The present disclosure relates to switching drivers for driving a transducer. A switching driver (202) has supply nodes for receiving supply voltages (VSH, VSL) defining at least one input voltage and an output node (104). A controller (205) controls operation of the first switching driver to generate a drive signal for the transducer at the output node (104), based on an input signal (Sin). A first capacitor (201a) is connected between first and second capacitor nodes (104, 204a) and a second capacitor (201b) is connected between the second capacitor node (204a) and a third capacitor node (204b). A network of switches (203) selectively connects any of the driver output node, the second capacitor node and the third capacitor node to either of a respective pair of said supply nodes, with the first capacitor node connected to the first driver output node.