Compact Voltage Supply Switching With Boosted Gate Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Voltage supply switches in RF power amplifiers experience significant IR voltage drop due to large DC currents, leading to performance degradation, and using lower threshold voltage transistors to minimize switch-on resistance increases die area and limits breakdown voltage.
Innovation Solution
A digital control circuit is employed to manage voltage supply switches using lower threshold and breakdown voltage transistors, with a first and second gain voltage path to control switch-on and switch-off states, and transition protection circuits to prevent over-voltage stressing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If larger switch transistors are used to minimize ON resistance and reduce IR voltage drop, then the IR voltage drop is reduced, but the die area occupied increases
Solution Approach 1:
The patent changes the voltage parameter by applying a boosted gate voltage (e.g., 1.2V or 1.8V) to the switch transistor gates instead of the standard logic level voltage. This parameter change enables the use of smaller transistor sizes while maintaining low ON resistance, thereby reducing die area while keeping IR voltage drop acceptable
2Area of stationary object
If transistors with lower threshold voltage are used to reduce device size, then the die area is reduced, but the breakdown voltage is limited
Solution Approach 1:
The patent introduces a voltage booster circuit as an intermediary component that generates a higher gate voltage than the standard logic level. This intermediary voltage source enables transistors to operate in a regime where they can achieve both small size and adequate breakdown voltage handling capability, as the boosted voltage compensates for the lower threshold voltage of small transistors during switching operations
3Power
If higher supply voltage is used at the RF power amplifier, then the maximum output power is increased, but the power efficiency during lower output power modes deteriorates
Solution Approach 1:
The patent implements dynamic voltage supply switching that allows the RF power amplifier to operate at different supply voltages depending on the output power requirement. The voltage supply switch dynamically selects between higher voltage (for maximum power) and lower voltage (for efficiency), enabling the system to adapt its power consumption to the actual operating conditions rather than being fixed at a single voltage level
Data Source
AI summary
Methods and apparatuses are provided in which a level shifter of a digital control circuit for a switchable voltage supply circuit shifts a domain level of a first input. A first inverter of the digital control circuit inverts output of the first level shifter to output a first gain voltage to turn on a first switch of the switchable voltage supply circuit or output a second gain voltage to turn off the first switch. A second inverter of the digital control circuit inverts a second input to output a third gain voltage to turn on a second switch of the switchable voltage supply circuit or output a fourth gain voltage to turn off the second switch. The first gain voltage is greater than the third gain voltage.