Charge Pump External Capacitor Parasitic Loss Reduction
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Solution Overview
Problem
Integrated circuits, particularly memory devices, face energy inefficiency due to parasitic capacitance in on-die capacitors, leading to substantial energy loss during charge pumping operations, especially in devices with limited power supplies like batteries.
Innovation Solution
Implementing external pump capacitors off-die and maintaining charge pump switches on-die, along with optional tank capacitors and control circuitry, to minimize current and energy loss by using low-parasitic-capacitance technologies like ceramic capacitors and adjusting peak current through max current control and regulation circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If on-die capacitors are used in charge pumps, then integration is improved, but parasitic capacitance increases causing energy loss
Solution Approach 1:
The patent extracts the pump capacitor from the integrated circuit die and places it externally. The charge pump circuitry remains on-die, but the capacitor that causes parasitic losses is moved off-chip, eliminating the harmful parasitic capacitance to substrate while maintaining the charge pumping function.
Solution Approach 2:
The charge pump system is segmented into two parts: the control circuitry (switches, logic) remains integrated on the die, while the energy storage element (capacitor) is separated and placed externally. This segmentation allows each component to be optimized independently for its specific function.
2Loss of energy
If external pump capacitors are used, then energy efficiency is improved, but device complexity increases
Solution Approach 1:
The bond pad serves as an intermediary connection between the on-die charge pump circuitry and the external pump capacitor. This intermediary allows the system to benefit from low-parasitic external capacitors while maintaining the advantages of integrated control circuitry.
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 enhances the energy efficiency of DC-to-DC conversion in memory devices by reducing parasitic capacitance effects, allowing for high-efficiency voltage generation with reduced power consumption, suitable for low-voltage operation in densely populated devices.
Implementation Method 1
Charge pumps are known in the art as on-chip voltage generators capable of providing a voltage more positive than the most positive external supply or more negative than the most negative external supply
Implementation Method 2
energy efficiency of charge pumps is often plagued by issues such as parasitic capacitance stemming from capacitors being implemented in silicon or metal
Data Source
AI summary
Systems and methods of memory operation involving charge pump circuitry located on a die and coupled to external pump capacitors are disclosed. In one embodiment, an exemplary system may comprise a memory die containing a memory array and charge pump circuitry configured to generate a pump voltage supplied to the memory array, and one or more pump capacitors located external to the die and configured to hold stored charge that is used to generate the pump voltage. Some embodiments may include a tank capacitor, also located off-die, to condition the charge provided from the pump capacitor. According to further embodiments, the charge pump circuitry may include one or both of max current control circuitry and/or switch resistance control circuitry that may be utilized, for example, to adjust peak current.