Reconfigurable SPAD High-Voltage Circuit for Dual Package Modes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Time-of-flight sensor systems face challenges with high voltage generation circuitry being external to the package, leading to increased space and cost due to separate production lines for different SOC implementations, and the need for a single SOC to support both external and internal high voltage generation modes.
Innovation Solution
A reconfigurable system-on-a-chip (SOC) with integrated switching circuitry and overvoltage/undervoltage detection, allowing for either external or internal high voltage generation, enabling a single SOC to function with both configurations by selectively connecting components and generating temperature-independent reference currents/voltages for high voltage regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If high voltage generation circuitry is external to the package, then the SOC can support both external and internal configurations, but the system occupies more space and increases manufacturing complexity
Solution Approach 1:
The SOC is designed with universal high voltage generation capabilities that can operate in both external and internal configurations. The circuit includes configurable switching elements and control logic that enable the same SOC to interface with external high voltage generation circuitry or utilize integrated internal high voltage generation, eliminating the need for different SOC versions for different configurations.
Solution Approach 2:
The patent introduces intermediary control circuitry and switching mechanisms within the SOC that mediate between the external high voltage generation circuitry and the sensor array. This intermediary layer enables the SOC to adapt to external configurations while maintaining compact packaging, as the switching and control functions are integrated within the SOC boundaries.
2Adaptability or versatility
If high voltage generation circuitry is external to the package, then configuration flexibility is improved, but manufacturing cost increases due to separate production lines
Solution Approach 1:
The SOC incorporates universal high voltage generation support that allows a single production line to manufacture SOCs for both external and internal configurations. The circuit design includes optional enable signals and configurable switching elements that can be activated or deactivated based on the intended application, eliminating the need for separate production lines for different configurations.
Solution Approach 2:
The high voltage generation circuitry includes dynamic configuration capabilities through control signals that can switch between external and internal operation modes. This dynamic reconfigurability is achieved through programmable switching elements and control logic that adapt the circuit behavior based on external control signals, allowing a single SOC design to serve multiple manufacturing configurations.
3Ease of manufacture
If a single SOC supports both external and internal high voltage generation, then manufacturing complexity is reduced, but the circuit design becomes more complex
Solution Approach 1:
The high voltage generation circuit is segmented into distinct functional modules: a high voltage generation block, a control block with switching elements, and a sensor array interface block. Each module is designed with defined interfaces and control signals, allowing the same modules to be configured for either external or internal operation. This segmentation reduces manufacturing complexity by using standardized building blocks while managing circuit design complexity through modular organization.
Solution Approach 2:
The circuit design utilizes parameter changes through control signals that modify the operational state of switching elements and control logic. By changing control parameters (enable signals, mode selection bits), the same physical circuit can operate in different configurations. This approach manages circuit design complexity by using parameter-based reconfiguration rather than requiring physically different circuit implementations.
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 reduces manufacturing complexity and cost by allowing a single SOC to support both external and internal high voltage generation modes, optimizing space usage and production efficiency while maintaining high voltage regulation accuracy.
Implementation Method 1
When the SPAD 14 is struck by an incoming photon, an output pulse is sourced from the anode of the SPAD 14
Implementation Method 2
a boost converter 20 that alternatingly creates a connection that transfers energy from the battery VBAT to an inductor L and disrupts that connection to thereby create a ripple current that is used to generate the high voltage (VHV)
Implementation Method 3
the breaking circuit 21 is now enabled and causes the switch 24 to close, thereby connecting the inductor L to ground. The inductor current ramps up... The controller 22 then causes the switch 24 to open, thereby breaking the connection between the inductor L and ground and causing the inductor current to rapidly decrease
Data Source
AI summary
A system-on-a-chip (SOC) within a package includes a reference generator, a matching circuit, a programmable current generator, a PWM controller, an overvoltage/undervoltage detector receiving a high voltage from a third output pad, a multiplexer passing an input signal to a second output pad, and a SPAD receiving the high voltage. Switching circuitry includes a first switch between the reference generator and an input of the programmable current generator, a second switch between the input of the current generator and the output of the matching circuit, a third switch between the reference generator and an input of the matching circuit, a fourth switch between an output of the current generator and a tap of a ladder within the overvoltage/undervoltage detector, a fifth switch between an output of the current generator and the first output pad, and a sixth switch between the output of the PWM controller and the first output pad.