Variable-Frequency Charge Pump for Stable Boost Voltage
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Solution Overview
Problem
Conventional constant voltage boost power supplies for semiconductor memory devices face challenges in maintaining a stable output voltage across varying load currents and supply voltages, leading to inefficiencies and increased chip area requirements due to the need for large decoupling capacitors, which increase production costs.
Innovation Solution
A constant voltage boost power supply system incorporating a voltage-controlled variable frequency oscillator, a charge pump, a voltage dividing circuit, and a differential amplifier, which adjusts the clock signal frequency based on control voltage to maintain a stable output voltage, reducing the need for large capacitors and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional clock frequency control is used in charge pump, then the boost power supply can be configured for specific supply voltages and electrical characteristics, but the output voltage cannot be kept constant across varying supply voltages and load currents
Solution Approach 1:
The patent implements a feedback control system where the oscillation frequency of the charge pump is automatically adjusted based on the output voltage level. A voltage detection circuit monitors the output voltage and feeds this information back to the oscillator, which adjusts its frequency accordingly to maintain constant output voltage across varying supply conditions and load currents.
Solution Approach 2:
The patent changes the operating parameter of the charge pump from fixed frequency to variable frequency operation. The oscillation frequency is dynamically adjusted based on output voltage feedback, allowing the system to adapt to different supply voltages and load conditions while maintaining stable output voltage.
2Reliability
If on-off control system is used to keep output voltage constant, then voltage stability is improved, but consumption current increases particularly in large load currents
Solution Approach 1:
The patent transitions from static on-off control to dynamic frequency modulation control. Instead of simply turning the charge pump on or off, the system dynamically adjusts the oscillation frequency to match load requirements, reducing unnecessary switching operations and lowering consumption current while maintaining voltage stability.
Solution Approach 2:
The patent uses periodic charge pump operation with variable frequency instead of continuous or simple on-off cycling. The charge pump operates periodically at adjusted frequencies based on load conditions, reducing average current consumption while maintaining stable output voltage through feedback control.
3Power
If charge pump consumption current is increased for large load current, then power supply capability is improved, but chip area and production costs increase
Solution Approach 1:
The patent implements dynamic current adjustment by varying the oscillation frequency rather than increasing device size. The charge pump delivers higher current when needed by operating at higher frequencies, and reduces frequency during low-load conditions, providing adaptive power supply capability without requiring larger chip area.
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 system achieves stable voltage regulation with reduced ripple and capacitance requirements, minimizing chip area and production costs while effectively managing load current changes.
Implementation Method 1
a voltage-controlled variable frequency oscillator for producing and supplying a clock signal and changing an oscillating frequency of the supplied clock signal according to an input control voltage
Implementation Method 2
a charge pump into which the clock signal is fed, the charge pump performing a pumping operation in synchronization with the clock signal to boost an input voltage and supply an output voltage in which the input voltage is boosted
Implementation Method 3
a voltage dividing circuit for dividing the output voltage of the charge pump to supply a monitor voltage
Implementation Method 4
a differential amplifier into which the monitor voltage and a reference voltage are fed, the differential amplifier amplifying a potential difference between the monitor voltage and the reference voltage to supply the control voltage
Data Source
AI summary
A constant voltage boost power supply according to an aspect of the invention includes a voltage-controlled variable frequency oscillator that produces and supplies a clock signal and changes an oscillating frequency of the supplied clock signal according to an input control voltage; a charge pump into which the clock signal is fed, the charge pump performing a pumping operation in synchronization with the clock signal to boost an input voltage and supply an output voltage in which the input voltage is boosted; a voltage dividing circuit that divides the output voltage of the charge pump to supply a monitor voltage; and a differential amplifier into which the monitor voltage and a reference voltage are fed, the differential amplifier amplifying a potential difference between the monitor voltage and the reference voltage to supply the control voltage.