Ultrasound Die Stack with Split TX/RX ASICs for Lower Power

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Solution Overview

Problem

Conventional ultrasound systems are large, complex, and expensive, limiting their accessibility to large medical facilities, while existing monolithic ultrasound devices face challenges in efficiently integrating analog and digital circuitry due to differing voltage and technology node requirements.

Innovation Solution

Implementing integrated transmit and receive circuitry in separate devices, with the transmit circuitry operating at higher voltages in a more advanced technology node and the receive circuitry operating at lower voltages in a less advanced node, connected via through-silicon vias and high-speed communication links, allowing for a three-die stack configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If transmit circuitry and receive circuitry are integrated in the same device, then device complexity is reduced, but power consumption increases due to conflicting voltage requirements

Engineering Contradiction:
Improvedevice complexityVSAvoidpower consumption
Core Design Contradiction:
Device complexityVSUse of energy by moving object

Solution Approach 1:

The ultrasound device is divided into separate transmit and receive devices, each optimized for their specific voltage requirements. The transmit device operates at higher voltages (e.g., 5-10V) while the receive device operates at lower voltages (e.g., 1.8-3.3V), eliminating the need for the receive device to handle high voltage swings and thereby reducing overall power consumption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each device is designed with local optimization for its specific function. The transmit device uses technology nodes and voltage levels optimized for high-power transmission, while the receive device uses technology nodes optimized for low-power signal reception. This local quality approach allows each component to operate at peak efficiency for its specific role.

Inventive Principle:
Principle #3Local quality

2Stress or pressure

If transmit circuitry operates at higher voltages in advanced technology node, then acoustic signal pressure is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveacoustic signal pressureVSAvoidmanufacturing complexity
Core Design Contradiction:
Stress or pressureVSEase of manufacture

Solution Approach 1:

The system is segmented into transmit and receive devices that can be manufactured separately using different technology nodes. The transmit device can be fabricated in an advanced technology node (e.g., 65nm or smaller) to achieve high acoustic signal pressure, while the receive device can be manufactured in a less advanced node, allowing each to be optimized independently for its specific performance requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the voltage and technology node parameters differently for transmit and receive devices. The transmit device uses higher voltages and advanced technology nodes to maximize acoustic pressure output, while the receive device uses lower voltages and potentially less advanced nodes, optimizing the overall system performance while managing manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If receive circuitry operates at lower voltages in less advanced node, then power consumption is reduced, but data processing capability is limited

Engineering Contradiction:
Improvepower consumptionVSAvoiddata processing capability
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

High-speed communication links and through-silicon vias act as intermediaries between the receive device and the imaging system. These high-bandwidth interfaces enable the receive device to offload processed data efficiently, compensating for its lower local processing capability by maintaining high data throughput to external processing resources.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The architecture moves processing capability to another dimension by separating the low-power signal reception function from the high-power data processing function. The receive device focuses on efficient signal acquisition at low power, while data processing is handled by external systems or the transmit device, which has greater processing resources available.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Use of energy by moving object

If separate devices are used for transmit and receive circuitry, then power management is improved, but device complexity increases

Engineering Contradiction:
Improvepower managementVSAvoiddevice complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent replaces complex voltage management mechanisms within a single device with a simpler inter-device communication architecture. Through-silicon vias and high-speed communication links provide straightforward electrical connections between the transmit and receive devices, eliminating the need for complex voltage switching and isolation circuitry that would be required in an integrated design.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP3709894B1Ultrasound apparatuses and methods for fabricating ultrasound devices
Publication Date: 2026.02.25 BFLY OPERATIONS INC
  • EP3709894B1 patent drawingFigure 1
  • EP3709894B1 patent drawingFigure 2
  • EP3709894B1 patent drawingFigure 3

AI summary

Aspects of the technology described herein relate to an ultrasound device including a first die that includes an ultrasonic transducer, a first application- specific integrated circuit (ASIC) that is bonded to the first die and includes a pulser, and a second ASIC in communication with the second ASIC that includes integrated digital receive circuitry. In some embodiments, the first ASIC may be bonded to the second ASIC and the second ASIC may include analog processing circuitry and an analog-to-digital converter. In such embodiments, the second ASIC may include a through-silicon via (TSV) facilitating communication between the first ASIC and the second ASIC. In some embodiments, SERDES circuitry facilitates communication between the first ASIC and the second ASIC and the first ASIC includes analog processing circuitry and an analog-to-digital converter. In some embodiments, the technology node of the first ASIC is different from the technology node of the second ASIC.