Switched Capacitive Load Kickback Noise Reduction Buffer
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Solution Overview
Problem
Integrated electronic semiconductor devices face challenges in reducing kickback noise when switching capacitive loads, particularly due to charge injection and voltage glitches, which affect the voltage levels at input nodes and can trigger changes in comparator outputs, and existing solutions like high-performance buffers consume power and introduce offset voltages.
Innovation Solution
An electronic device configuration with a first stage having an input capacitance, a switch, and a low-performance buffer where the buffer is activated before switching configurations to charge the input capacitance, then switched off to minimize power consumption and kickback noise, with the buffer's input capacitance optimized to match the charge injection requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a high-performance buffer is used to block kickback noise, then kickback noise is reduced, but power consumption increases and offset voltage is introduced
Solution Approach 1:
The buffer is activated periodically only when needed (during switching operations) rather than continuously. The control circuit activates the buffer before a switching operation and deactivates it after, creating a periodic action pattern that reduces power consumption while maintaining kickback noise protection during critical moments.
Solution Approach 2:
The buffer is activated in advance before the actual switching operation occurs. The control circuit detects the upcoming switching event and activates the buffer beforehand, allowing it to be ready to block kickback noise when the switching happens, while being inactive during normal operation to save power.
2Object-affected harmful factors
If the buffer is kept active continuously, then kickback noise is consistently blocked, but power consumption increases
Solution Approach 1:
The buffer operates in periodic cycles of activation and deactivation based on switching events rather than remaining continuously active. This periodic operation pattern maintains protection during needed moments while minimizing energy loss during idle periods.
Solution Approach 2:
The control circuit automatically manages the buffer's activation and deactivation based on detected switching events. The system serves itself by monitoring its own operational state and activating the buffer only when kickback noise protection is actually needed, eliminating the need for continuous operation.
3Use of energy by moving object
If a low-performance buffer with small input capacitance is used, then power consumption is reduced, but charge injection capability is limited
Solution Approach 1:
The buffer is activated in advance of the switching event, allowing it sufficient time to charge its output capacitance to the appropriate voltage level before the switching occurs. This preliminary action ensures that even a low-performance buffer with small capacitance can provide adequate charge injection capability when needed.
Solution Approach 2:
The patent uses a low-performance buffer that can be replaced or reactivated for each switching event rather than requiring a continuously operating high-performance buffer. The buffer provides its function temporarily during switching events and then remains inactive, effectively using a 'disposable' approach to maintain reliability while reducing power consumption.
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 configuration effectively reduces kickback noise at the input of sensitive stages while minimizing power consumption by using a low-performance buffer that can be switched off after charging, thereby reducing power consumption and offset voltages.
Implementation Method 1
the buffer is activated before switching configurations to charge the input capacitance
Data Source
AI summary
An electronic device which includes a first stage having an input capacitance, a switch, a buffer and a second stage having an input sensitive to charge injection and/or voltage glitches. An input of the buffer and the input of the second stage are coupled together at a first node which is configured to be coupled to a voltage source for supplying a reference voltage to the input of the first stage having the input capacitance. In a first configuration of the switch, the switch is arranged to either connect the input of the first stage to the first node and to disconnect the input of the first stage from an output of the buffer. In a second configuration of the switch, to connect the input of the first stage to the output of the buffer and to disconnect the input of the first stage from the first node.