Switchable Diode Pad Circuit for Wider Input Voltage Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing input-output circuits in electronic chips are limited by the inflexibility of having either intolerant or tolerant connection pads, which restricts the range of admissible input voltages and lacks modifiability, making them unsuitable for diverse applications.
Innovation Solution
A device comprising three MOS transistors connected in series, where a digital signal controls the transistors to switch between a diode and an open circuit, allowing for configurable pads that can behave as either intolerant or tolerant, providing flexibility in voltage handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diodes are used to protect against current injections, then protection against harmful effects is improved, but the range of admissible input voltages is restricted
Solution Approach 1:
The patent applies the dynamics principle by making the protection configuration switchable rather than fixed. A control circuit dynamically reconfigures the connection between the pad and protection elements based on operational mode signals, allowing the same pad to function as either an intolerant pad (with diode protection) or a tolerant pad (with extended voltage range) as needed by the application.
2Adaptability or versatility
If tolerant pads are used to expand voltage range, then adaptability is improved, but protection against current injections is reduced
Solution Approach 1:
The patent resolves this contradiction by implementing a dynamic reconfiguration system where the protection level can be adjusted based on operational requirements. When high voltage tolerance is needed, the circuit configures for extended voltage range; when maximum protection is needed, it reconfigures to provide full diode protection, allowing both characteristics to be optimized at different times.
3Ease of manufacture
If pad type is decided before chip manufacture, then manufacturing simplicity is maintained, but flexibility of input-output circuits is reduced
Solution Approach 1:
The patent implements post-manufacturing configurability by incorporating control circuits and switching elements that allow the pad behavior to be changed after the chip has been manufactured. This is achieved through digital control signals that reconfigure the protection circuitry, enabling the same physical chip to adapt to different application requirements without requiring different manufacturing processes.
Solution Approach 2:
The patent makes each pad universal by enabling it to function in multiple modes -既可以作为intolerant pad提供强保护，又可以作为tolerant pad提供宽电压范围 - through the reconfiguration capability. This multi-functionality is achieved by adding control logic that can dynamically switch the pad's operational characteristics based on the intended application.
Data Source
AI summary
An electronic chip includes a chip core including an input terminal, an output terminal, an external pad, and an input-output circuit coupled to the chip core and the external pad. The input-output circuit includes an enable terminal coupled to the chip core, a connection terminal coupled to the external pad, a switchable diode device coupled between a supply voltage and a reference voltage, and a levelling circuit. The switchable diode device is coupled to the connection terminal and the enable terminal and is configured to operate as a diode in response to a control signal in a first state applied to the enable terminal and to operate as an open circuit in response to the control signal in a second state applied to the enable terminal. The levelling circuit is coupled to the connection terminal, the input terminal of the chip core, and the output terminal of the chip core.