Source Driver Circuit Layout Using Time-Multiplexed DACs
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Solution Overview
Problem
Conventional flat panel display devices require a large layout area due to the numerous digital-to-analog converters (DACs) needed for each data line, which increases the size and complexity of the source driver circuit.
Innovation Solution
A source driver circuit design that uses a reduced number of DACs by employing multiple driving operations within a unit sourcing period, where each DAC drives multiple data lines, and each driver selectively outputs analog data from different DACs to generate source voltages for R, G, and B image signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If one DAC is disposed on each data line to provide source voltages, then the source voltages can be generated accurately for each data line, but the layout area becomes very large due to the large number of DACs required
Solution Approach 1:
The patent merges the functionality of multiple DACs into a single DAC by implementing multiple driving operations within one unit sourcing period. The single DAC sequentially generates source voltages for different data lines through time-multiplexed operations, eliminating the need for separate DACs on each data line while maintaining voltage generation accuracy.
Solution Approach 2:
The patent employs periodic action by performing multiple driving operations within a unit sourcing period. The single DAC operates periodically to generate source voltages for different data lines in sequence, using timing signals to control the periodic generation and switching of voltages to appropriate data lines throughout the sourcing period.
2Ease of operation
If a conventional source driver circuit with many DACs is used, then each data line receives dedicated source voltage control, but the device complexity and power consumption increase significantly
Solution Approach 1:
The patent makes a single DAC universal by enabling it to perform multiple functions of generating source voltages for different data lines through multiple driving operations. The DAC is controlled by timing signals to sequentially serve different data lines, making one component perform the work of multiple dedicated components while maintaining full control capability.
Solution Approach 2:
The patent introduces dynamics by making the DAC's function time-dependent. The single DAC dynamically switches between serving different data lines within the unit sourcing period, with its output destination controlled by dynamic timing signals. This dynamic allocation allows one DAC to replace multiple static DACs.
3Area of stationary object
If multiple driving operations are performed within a unit sourcing period using a single DAC, then the number of DACs is reduced and layout area is minimized, but the timing control complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-generating the timing signals that control the multiple driving operations before the actual voltage generation occurs. The timing signals are prepared in advance to coordinate the single DAC's sequential operations, ensuring proper synchronization without adding complex real-time control logic during the voltage generation process.
Data Source
AI summary
A flat panel display device and a source driver circuit for the flat panel display device are provided for performing multiple driving operations within a unit sourcing period. In the flat panel display device, multiple driving operations are performed within the unit sourcing period, and source voltages are supplied to a selected number of data lines in each driving operation. In this case, one DAC is driven to generate source voltages for a plurality of data lines. In the flat panel display device, the number of the DACs is reduced and the overall layout area is greatly reduced. Also, standby power consumption can be greatly reduced due to the reduced number of amplifiers. Since the source voltages provided by the same amplifier are provided to adjacent data lines, a metal layer can be easily wired in the display panel.