Current Regulator Linear Mode for LED Backlighting
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Solution Overview
Problem
Conventional current DACs for High-Dynamic Range displays with LED backlighting have high power consumption and a large footprint due to large saturated output voltage, limiting the sensitivity of light intensity control and requiring complex circuits.
Innovation Solution
A current regulator with a voltage controller operating a current steering circuit in linear mode, utilizing a plurality of current cells and differential amplifiers to provide control voltages for switches, allowing each current cell to operate in a linear mode and reducing the output saturation voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional current DACs use saturated output voltage mode, then current control capability is achieved, but power consumption increases and footprint enlarges
Solution Approach 1:
The patent changes the operating mode of the current steering circuit from saturated output voltage mode to linear mode. By adjusting the control voltage to maintain the circuit in linear region operation, the output saturation voltage is reduced, which directly lowers power consumption while preserving current control capability through the linear relationship between control voltage and output current.
2Area of stationary object
If conventional current DACs use saturated output voltage mode, then current control is achieved, but circuit footprint increases
Solution Approach 1:
The patent transitions the current steering circuit from saturated mode to linear mode operation. This parameter change allows the same current control function to be achieved with reduced output voltage swing, enabling smaller transistor sizes and reduced circuit area while maintaining control precision through the linear voltage-current relationship.
3Measurement precision
If conventional current DACs are used, then LED current control is achieved, but light intensity control sensitivity is limited
Solution Approach 1:
The patent changes the operating parameter of the current steering circuit from saturated mode to linear mode. In linear mode, the output current has a linear relationship with the control voltage, providing finer resolution and higher sensitivity for light intensity control. This approach achieves improved precision without requiring more complex circuit topologies.
Data Source
AI summary
A current regulator and a method for regulating a current flowing through a device such as a semiconductor light source is presented. The current regulator has a voltage controller coupled to a current steering circuit. The voltage controller is adapted to operate the current steering circuit in a linear mode.