Low-Voltage Isolation Switch for Ultrasound Echo Signal Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ultrasonic transducer driving circuits suffer from high parasitic capacitance due to large components, which reduces the quality of echo signals in ultrasound applications.
Innovation Solution
A low voltage isolation switch with a real isolation block and protection block is introduced between the ultrasonic transducer and high voltage components, using a matrix of high voltage switches and a low voltage isolation switch to transmit high voltage signals and isolate during echo reception, reducing parasitic capacitance effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If large components are used in ultrasonic transducer driving circuits, then high voltage signals can be transmitted effectively, but parasitic capacitance increases reducing echo signal quality
Solution Approach 1:
The circuit is divided into distinct functional blocks: a high voltage transmission path with switches for signal output, and a separate low voltage control path for switch control. This segmentation allows high voltage components to be isolated from low voltage control circuitry, reducing parasitic capacitance coupling between them while maintaining high voltage transmission capability.
Solution Approach 2:
A low voltage isolation switch is introduced as an intermediary component between the high voltage transmission channel and the low voltage control circuitry. This isolation switch acts as a mediator that blocks parasitic capacitance coupling while allowing controlled signal transmission, thus reducing the harmful parasitic effects without compromising high voltage signal transmission.
2Productivity
If high voltage components are placed close to the transducer, then signal transmission efficiency improves, but parasitic capacitance in parallel with the transducer increases
Solution Approach 1:
The circuit architecture segments high voltage transmission components from low voltage control components through physical and electrical isolation. The high voltage switches and associated components are separated from the transducer by isolation barriers, reducing parasitic capacitance while maintaining transmission efficiency through direct high voltage switching paths.
Solution Approach 2:
Isolation switches and isolation barriers are positioned as intermediary elements between the high voltage transmission path and the transducer. These intermediaries reduce parasitic capacitance coupling to the transducer while allowing efficient high voltage signal transmission through controlled switching mechanisms.
3Measurement precision
If isolation switch is added to reduce parasitic capacitance, then echo signal quality improves, but device complexity increases
Solution Approach 1:
The circuit is segmented into modular functional blocks (high voltage transmission block, low voltage control block, isolation block) that can be independently designed and optimized. This modular segmentation manages complexity by organizing the isolation switch and associated components into distinct functional units with clear interfaces.
Solution Approach 2:
The low voltage isolation switch serves as a compact intermediary component that provides effective parasitic capacitance reduction without requiring complex circuit topologies. The isolation switch implementation uses standard semiconductor devices arranged in a relatively simple configuration, managing device complexity while achieving improved echo signal quality.
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 effectively transmits high voltage signals to the ultrasonic transducer while minimizing the impact of parasitic capacitance, ensuring accurate signal transmission and reception, thus improving the quality of echo signals and reducing the size of components needed.
Implementation Method 1
prior art ultrasonic transducer driving circuits use components with rather big sizes. These components however add high parasitic capacitances in parallel to the transducer
Implementation Method 2
an isolation block (8), connected to the connection terminal (pzt), to the first output terminal (HVout) and, through a protection block (9), to the driving central circuit node (Xc)
Implementation Method 3
a diode block (7), comprising first and second transmission diodes (DN1, DN2), connected in antiparallel
Implementation Method 4
The ultrasounds are normally generated by a piezoceramic crystal inserted in a probe
Data Source
AI summary
A low voltage isolation circuit is coupled between an input terminal for receiving a high voltage signal and an output terminal for transmitting the high voltage signal to a load. The isolation circuit includes a driving block; having a first driving transistor coupled between a first voltage reference and an intermediate node and a second driving transistor coupled between the intermediate node and a second voltage reference; an isolation block connected between the input and output terminals and, through a protection block to the intermediate node. The protection block includes first and second protection transistors (MD1, coupled in anti-series to each other and having control terminals receiving complementary protection driving signals. The isolation block includes a voltage limiter block, a diode block and a control transistor connected across the diode block between the input and output terminals and having a control terminal connected to the intermediate node through the protection block.