Reference voltage generating circuit and display device
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Solution Overview
Problem
The complexity and cost of the gamma voltage chip in display devices are increased due to the large number of operational amplifiers required for converting voltage signals, which complicates the internal circuit structure.
Innovation Solution
A reference voltage generating circuit is designed with a timing control circuit, digital-to-analog conversion circuit, operational amplifier circuit, switch control circuit, and switch circuits to sequentially control the output of analog voltage signals, reducing the number of operational amplifiers needed and simplifying the circuit structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple operational amplifiers are used to convert voltage signals in the gamma voltage chip, then the voltage signal conversion function is improved, but the circuit complexity and cost increase
Solution Approach 1:
The patent segments the voltage signal conversion process into two distinct stages: (1) digital-to-analog conversion stage using DAC circuits to convert digital voltage signals to analog signals, and (2) voltage amplification stage using operational amplifiers to amplify the analog signals to required voltage levels. This segmentation allows each stage to use optimized circuit structures, reducing the total number of operational amplifiers needed while maintaining conversion functionality.
Solution Approach 2:
The patent introduces an intermediate analog voltage signal as a mediator between the digital-to-analog conversion stage and the final voltage output stage. The DAC circuits generate intermediate analog voltage signals that are then processed by operational amplifiers, allowing the system to achieve the required voltage conversion with fewer operational amplifiers by utilizing this intermediate representation.
2Reliability
If multiple operational amplifiers are used in the gamma voltage chip, then the voltage signal conversion capability is improved, but the manufacturing cost increases
Solution Approach 1:
By segmenting the conversion process into DAC-based digital-to-analog conversion and operational amplifier-based voltage amplification, the patent reduces the total count of operational amplifiers required. Since operational amplifiers are typically more expensive than DAC circuits, this segmentation directly lowers manufacturing costs while preserving the voltage signal conversion capability.
Solution Approach 2:
The patent changes the working parameters and signal forms at different stages: digital voltage signals are converted to analog voltage signals by DAC circuits, then these analog signals are amplified by operational amplifiers to reach the final voltage levels. This parameter transformation approach allows the system to achieve the same functional result with a different circuit configuration that uses fewer expensive operational amplifiers.
3Device complexity
If the number of operational amplifiers is reduced, then the circuit complexity and cost are reduced, but the voltage signal conversion function must be maintained
Solution Approach 1:
The patent merges the digital-to-analog conversion function and voltage amplification function into a coordinated two-stage system. The DAC circuits and operational amplifiers work together in sequence, with the DAC output directly feeding into the operational amplifier input, creating an integrated voltage conversion solution that achieves the required functionality with fewer total components.
Solution Approach 2:
The operational amplifiers in the patent serve multiple functions: they amplify the analog voltage signals from the DAC circuits, provide impedance matching, and ensure proper signal levels for the display panel. This multi-functionality allows the system to maintain robust voltage signal conversion capability with a reduced number of operational amplifiers compared to using separate dedicated circuits for each function.
Data Source
AI summary
Disclosed are a reference voltage generating circuit and a display device. The reference voltage generating circuit includes a timing control circuit, a digital-to-analog conversion circuit, an operational amplifier circuit, a drive circuit, a switch control circuit, a first switch circuit, and a second switch circuit. The switch control circuit generates a control signal according to a frame start signal and a clock signal provided by the timing control circuit, and outputs the control signal to the first switch circuit and the second switch circuit to control the channels inside the first switch circuit and the second switch circuit to be turned on sequentially, such that an analog voltage signal output by the digital-to-analog conversion circuit can be output to the drive circuit through the first switch circuit, the operational amplifier circuit and the second switch circuit, to provide a reference voltage signal for the drive circuit.