Source Driver Output Buffer for Charge Sharing Without Extra Switches

Solution Overview

Problem

The existing source drivers for flat panel displays require additional switches to implement charge sharing, increasing manufacturing costs and die area due to the need for multiple switches to connect data lines and prevent buffer output to data lines during charge sharing operations.

Innovation Solution

A source driver design that includes a buffer device with amplifiers and a switch device for charge sharing, where the amplifier has a first current mirror with nodes connected during charge sharing, and a control logic to disable the output driver and enable switches for efficient charge sharing without additional large switches.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If additional switches are added to connect data lines during charge sharing operation, then charge sharing function is achieved, but manufacturing cost and die area increase

Engineering Contradiction:

Improvecharge sharing functionVSAvoidnumber of switches

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The existing switches in the buffer circuit are designed to perform multiple functions: both their original switching function and the additional charge sharing function. By controlling these existing switches with appropriate control signals, the patent eliminates the need for separate dedicated charge sharing switches, thereby reducing device complexity while maintaining charge sharing capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the charge sharing function with the existing buffer circuit switches. Instead of having separate switches for charge sharing, the control logic integrates this function into the existing switch structure, combining multiple functions into a single switch component to reduce overall device complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Adaptability or versatility

If additional switches are added to connect data lines during charge sharing operation, then charge sharing function is achieved, but manufacturing cost increases

Engineering Contradiction:

Improvecharge sharing functionVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The existing switches in the buffer circuit are designed to perform multiple functions: both their original switching function and the additional charge sharing function. By controlling these existing switches with appropriate control signals, the patent eliminates the need for separate dedicated charge sharing switches, thereby reducing device complexity while maintaining charge sharing capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the charge sharing function with the existing buffer circuit switches. Instead of having separate switches for charge sharing, the control logic integrates this function into the existing switch structure, combining multiple functions into a single switch component to reduce overall device complexity.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS9979363B2Source driver including output buffer, display driving circuit, and operating method of source driver

Publication Date: 2018.05.22 SAMSUNG ELECTRONICS CO LTD

AI summary

A source driver includes a buffer device including a plurality of buffers corresponding to a plurality of data lines, each of the plurality of buffers respectively including an amplifier configured to amplify an input signal and an output driver configured to output a driving signal to a corresponding data line among the plurality of data lines; and a switch device including a charge sharing switch configured to electrically connect the plurality of data lines to one another during a charge sharing operation, each of the amplifiers including a first current mirror having a reference current path including a first node and an output current path including a second node, and the first node of the reference current path and the second node of the output current path are electrically connected to each other during the charge sharing operation.