Snapback Clamp Circuit Calibration for ESD Protection
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Solution Overview
Problem
Existing clamp circuits, such as big FET and snapback clamp circuits, have limitations in responding quickly to supply voltage fluctuations and electrostatic discharge (ESD) events, leading to potential damage to electronic devices due to slow response times and high holding voltages.
Innovation Solution
A snapback clamp circuit with a programmable trigger voltage level, calibrated based on body-to-ground resistance and gate-to-source voltage, is used to rapidly clamp supply voltage fluctuations and protect against ESD, incorporating a clamp transistor and programmable resistance or bias devices to adjust the trigger voltage for effective glitch suppression and ESD protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a big FET clamp circuit is used to suppress supply voltage glitches, then the circuit can dissipate current in response to supply voltage exceeding trigger level, but the response time is slow and not suitable for certain applications
Solution Approach 1:
The patent changes the electrical parameters of the clamp circuit by using a FET with adjustable body-to-ground resistance and gate-to-source voltage. By modifying these parameters, the trigger voltage level can be calibrated to achieve both fast response time and effective protection, resolving the contradiction between speed and reliability.
2Reliability
If a snapback clamp circuit is used for ESD protection, then fast response time is achieved, but the holding voltage is relatively large which may damage circuit components
Solution Approach 1:
The patent makes the clamp circuit dynamic by introducing programmable resistance and bias devices that can adjust the trigger voltage level based on different operating conditions. This allows the circuit to provide strong ESD protection when needed while reducing the holding voltage to safe levels during normal operation, resolving the contradiction between protection capability and potential damage.
Solution Approach 2:
By calibrating the body-to-ground resistance and gate-to-source voltage parameters, the patent enables the snapback clamp circuit to adjust its holding voltage dynamically. This ensures that the circuit provides sufficient ESD protection while preventing damage to sensitive components, thus resolving the contradiction between reliability and harmful factors.
3Device complexity
If the trigger voltage level is fixed in a snapback clamp circuit, then the circuit structure is simple, but the circuit cannot be calibrated for different applications and trace inductances
Solution Approach 1:
The patent transforms the fixed trigger voltage level into a dynamic, adjustable parameter through the introduction of programmable resistance and bias devices. These components allow the circuit to be calibrated for different applications and trace inductances while maintaining a relatively simple overall structure, resolving the contradiction between device complexity and adaptability.
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
The snapback clamp circuit provides fast response times for supply glitch suppression and ESD protection, calibrated to prevent damage to electronic devices by adjusting the trigger voltage level based on specific application requirements, ensuring reliable and efficient operation.
Implementation Method 1
a 'snapback' clamp circuit may utilize a parasitic bipolar junction transistor (BJT) effect associated with a FET to dissipate current in response to the supply voltage exceeding a trigger voltage level associated with the snapback clamp circuit
Implementation Method 2
calibrating a trigger voltage level associated with the snapback clamp circuit by modifying a body-to-ground resistance associated with the clamp transistor via a control signal
Implementation Method 3
programming a programmable bias device of the snapback clamp circuit to bias a gate terminal of the clamp transistor to further calibrate the trigger voltage level
Data Source
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AI summary
A device includes a snapback clamp circuit configured to clamp a supply voltage in response to the supply voltage exceeding a trigger voltage level. In at least one embodiment, the snapback clamp circuit includes a clamp transistor and a programmable resistance portion that is responsive to a control signal to calibrate the trigger voltage level. Alternatively or in addition, the snapback clamp circuit may include a programmable bias device configured to calibrate the trigger voltage level by biasing a gate terminal of the clamp transistor. In another particular embodiment, a method of calibrating a snapback clamp circuit is disclosed. In another particular embodiment, a method of operating an integrated circuit is disclosed.