Integrated DAC Level Shifting for Low-Power Display Drive

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Solution Overview

Problem

Existing digital-to-analog converters (DACs) in flat panel displays require separate DC/DC power supply converters to generate higher digital drive voltages, leading to increased area usage and power consumption due to the need for additional level shifting circuits.

Innovation Solution

The integration of a level shifter within the DAC eliminates the need for a separate DC/DC power supply converter by using a boost circuit to generate higher digital drive voltages from a single power supply, reducing the complexity and power requirements of the logic and drive circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If separate DC/DC power supply converters and level shifting circuits are used to generate higher digital drive voltages, then the required voltage range for driving display devices is achieved, but the area occupied by logic and drive circuits increases and power consumption increases

Engineering Contradiction:
Improvepower consumptionVSAvoidcircuit complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent combines the level shifting function with the existing DAC circuit by integrating a level shifter into the DAC structure. This merging eliminates the need for separate DC/DC converters and standalone level shifting circuits, thereby reducing overall circuit complexity and power consumption while achieving the required voltage translation from 0-5V digital logic signals to 0-10V drive signals

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated level shifter within the DAC performs multiple functions: it converts digital logic levels (0-5V) to drive signal levels (0-10V) while simultaneously generating the analog output signal. This multi-functionality reduces the number of separate components needed, decreasing both area occupation and power consumption compared to using separate converters and level shifters

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Power

If separate DC/DC power supply converters and level shifting circuits are used to generate higher digital drive voltages, then the required voltage range for driving display devices is achieved, but the area occupied by logic and drive circuits increases

Engineering Contradiction:
Improvevoltage range capabilityVSAvoidarea occupied by circuits
Core Design Contradiction:
PowerVSArea of stationary object

Solution Approach 1:

The patent merges the level shifting functionality into the DAC circuit structure, eliminating the need for separate DC/DC converters and level shifting circuits. This integration achieves the required voltage translation from 0-5V to 0-10V while significantly reducing the total area occupied by logic and drive circuits

Inventive Principle:
Principle #5Merging (Combining)

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

This solution reduces the area occupied by the logic and drive circuits and decreases power consumption while maintaining the necessary voltage range for analog signal generation, enhancing the efficiency of flat panel display systems.

Implementation Method 1

using a boost circuit to generate higher digital drive voltages from a single power supply

Methodology Applied
Scientific EffectBoost circuit voltage multiplication:

Data Source

PatentEP1847985B1Digital to analog converter having integrated level shifter and method for using same to drive display device
Publication Date: 2009.11.18 SAMSUNG ELECTRONICS CO LTD
  • EP1847985B1 patent drawingFigure 1
  • EP1847985B1 patent drawingFigure 2
  • EP1847985B1 patent drawingFigure 3A

AI summary

A digital-to-analog converter (DAC) includes a decoder unit for receiving an external digital data signal operating over a first predefined voltage range (i.e., 0-5V); a resistor array for generating a plurality of gray voltages defined across a second voltage range that is substantially wider than the first predefined voltage range, and a voltage selecting unit for selecting one of the gray voltages based on an output of the decoder unit, wherein the decoder unit includes a plurality of decoder stages and first and second boost circuits for generating output signals operating over a third voltage range (i.e., 0-7V) that is substantially wider than the first predefined voltage range while not requiring an additional power supply for producing voltages of the third voltage range (i.e., 0-7V).