Reference Voltage Correction Circuit for Power Amplifier Variations
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Solution Overview
Problem
Variations in transmission power characteristics of high-frequency power amplifier devices due to manufacturing variations lead to complex management and potential mismatches between bias generation circuits and output stage transistors, resulting in inconsistent performance.
Innovation Solution
A reference-voltage generating circuit, regulator circuit, and correction circuit with a buffer having a voltage gain of approximately 1 are introduced, utilizing resistance paths to correct output voltage and reduce variations by selectively supplying current to one of three resistance paths based on the output voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bias generation circuit and output stage transistor are different semiconductor chips, then variations in transmission power characteristics can be offset by test results, but management of combination becomes complex and many chips cannot obtain combination partners
Solution Approach 1:
The patent combines the bias generation circuit and output stage transistor into a single semiconductor integrated circuit device. This integration eliminates the need for complex combination management between separate chips while maintaining the ability to offset variations through internal matching. The unified structure allows direct correlation between bias generation and transistor characteristics, resolving the management complexity issue.
Solution Approach 2:
The patent introduces a correction circuit as an intermediary component that receives the reference voltage from the bandgap reference circuit and adjusts it based on detected variations. This correction circuit acts as a mediator between the reference voltage generation and the bias application, enabling automatic compensation for manufacturing variations without requiring external combination management.
2Ease of operation
If bandgap reference circuit is used to generate bias voltage, then bias can be generated for power control, but variations in transmission power characteristics occur due to manufacturing variations
Solution Approach 1:
The patent implements a feedback mechanism where the correction circuit detects variations in the reference voltage output from the bandgap reference circuit and automatically adjusts the bias voltage accordingly. This closed-loop feedback system compensates for manufacturing variations in real-time, maintaining consistent transmission power characteristics while preserving the ease of power control operation.
Solution Approach 2:
The patent changes the electrical parameters of the bias voltage by introducing a correction factor through the correction circuit. This circuit modifies the reference voltage parameter based on detected variations, effectively adjusting the bias characteristics to compensate for manufacturing tolerances. The correction circuit alters voltage levels dynamically to maintain precision despite manufacturing variations.
3Manufacturing precision
If correction circuit with buffer having voltage gain of approximately 1x is used, then variations in transmission power characteristics are reduced, but device complexity increases
Solution Approach 1:
The patent applies partial correction action through the correction circuit, which provides just enough adjustment to compensate for manufacturing variations without over-correcting or requiring excessive circuit complexity. The buffer with approximately 1x voltage gain provides sufficient correction capability while maintaining signal integrity, achieving the right balance between precision improvement and complexity addition.
Data Source
AI summary
The invention provides a semiconductor integrated circuit device and a high-frequency power amplifier module capable of reducing variations in the transmission power characteristics. The semiconductor integrated circuit device and the high-frequency power amplifier module each include, for example, a bandgap reference circuit, a regulator circuit, and a reference-voltage correction circuit which is provided between the bandgap reference circuit and the regulator circuit and which includes a unity gain buffer. The reference-voltage correction circuit corrects variations in a bandgap voltage from the bandgap reference circuit. The reference-voltage correction circuit includes first to third resistance paths having mutually different resistance values, and corrects the variations by selectively supplying a current which reflects an output voltage of the unity gain buffer to any one of the first to third resistance paths. The selection in this case is performed by connecting a bonding wire to any one of the terminals REF1 to REF3.