Self-Timed Charge Pump Circuit for Accurate Supply Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charge pump circuits for generating supply voltage in memory circuits lack accuracy and require external oscillators, leading to inefficiencies and voltage fluctuations.
Innovation Solution
A charge pump circuit with multiple stages, each comprising a capacitor and current source, where the capacitors are switched in series and controlled by a comparator to provide a high-accuracy supply voltage, operating self-timed and self-adapting to load and temperature changes without an external oscillator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a charge pump circuit uses external oscillators and conventional voltage generation methods, then the circuit can operate, but the supply voltage accuracy deteriorates and voltage fluctuations increase
Solution Approach 1:
The charge pump circuit uses self-timed operation where the switching between charging and discharging phases is automatically controlled by the circuit itself through feedback from the capacitors and current sources, eliminating the need for external oscillators. This self-regulating mechanism ensures accurate supply voltage generation by directly controlling the charge transfer based on actual circuit state, thereby improving both voltage accuracy and stability.
2Ease of operation
If a charge pump circuit uses external oscillators and clock generators, then the circuit can be controlled, but the device complexity increases
Solution Approach 1:
The invention extracts and removes the external oscillator and clock generator components from the charge pump circuit. The timing and control functions previously performed by external components are now integrated into the charge pump itself through self-timed operation, where the charging and discharging phases are automatically sequenced based on the circuit's internal state, thereby reducing device complexity while maintaining controllability.
Solution Approach 2:
The control functionality previously separated into external oscillators and clock generators is merged into the charge pump circuit itself. The switching between operational phases is controlled by the interaction between the capacitors and current sources within the circuit, combining the functions of voltage generation and timing control into a single integrated system, thus reducing the number of components and simplifying the overall circuit structure.
3Device complexity
If a charge pump circuit uses conventional charging methods without current sources, then the circuit is simpler, but the voltage accuracy deteriorates
Solution Approach 1:
The invention changes the charging method from conventional voltage-based charging to current-source-based charging. Each capacitor is charged by a dedicated current source that provides precise control over the charge transfer. This parameter change in the charging mechanism enables accurate supply voltage generation because the current sources can be designed to provide exact current values, and since charge equals current multiplied by time, the voltage accuracy is significantly improved while the added complexity is minimal.
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 solution achieves high accuracy and stability in supply voltage generation, reducing voltage fluctuations and eliminating the need for external clock generators or high voltage dividers, while maintaining constant current consumption and operating across a wide input voltage range.
Implementation Method 1
each having a capacitor and a current source... the capacitor of the first stage is switched in series to the current source of the first stage for charging the capacitor of the first stage
Data Source
AI summary
A charge pump circuit (11) comprises a first stage (31) and at least a second stage (32), each having a capacitor (130, 230) and a current source (100, 200). The charge pump circuit (11) is configured such that, in a first phase (A) of operation, the capacitor (130) of the first stage (31) is switched in series to the current source (100) of the first stage (31) and the capacitor (230) of the second stage (32) is switched in series to the current source (200) of the second stage (32) and that, in a second phase (B) of operation, the capacitor (130) of the first stage (31) and the capacitor (230) of the second stage (32) are switched in series for providing a supply voltage (VHF) at an output (15) of the charge pump circuit (11). A comparator signal (SCOM) is generated by comparing a voltage at an electrode of one of the capacitors (130, 230) of the first and the at least second stage (31, 32) with a reference voltage (VR). The first and the second phase (A, B) are set depending on the comparator signal (SCOM).