Driving control circuit for ligth-emitting device
AssigneeIndustrial Technology Research Institute
InventorChia-Ming Tsai
Life of this patent
Estimating the term…
Abstract
A driving control circuit for a light-emitting device. The circuit generates a high-speed modulated current to drive the light-emitting device. The circuit includes an adjustable gain circuit, a current output circuit, and a level control circuit. The adjustable gain circuit receives a digital signal and generates an output voltage controlled by a first control signal and a second control signal. The current output circuit includes a first transistor. A gate of the first transistor is coupled to the adjustable gain circuit, which adjusts a range of the gate voltage to generate the high-speed modulated current, and the level control circuit sets the voltages of the first control signal and the second control signal.
Claims16
A driving control circuit for a light-emitting device to generate a high-speed modulated current to drive the light-emitting device, comprising:
- an adjustable gain circuit for receiving a digital signal and generating an output voltage controlled by a first control signal and a second control signal;
- a current output circuit comprising a first transistor, wherein a gate of the first transistor is coupled to the adjustable gain circuit, and the adjustable gain circuit adjusts a range of the gate voltage to generate the high-speed modulated current;
- and
- a level control circuit for setting a voltage of the first control signal and a voltage of the second control signal, the level control circuit comprising:
- a duplicate circuit for receiving a high level signal and a low level signal and generating a first output current and a second output current;
- a first negative feedback current for setting the first current equal to a first predetermined current and outputting a voltage to set a voltage of the first control signal;
- and
- a second negative feedback current for setting the second current equal to a second predetermined current and outputting a voltage to set a voltage of the second control signal;
- wherein the high level signal raises the gate voltage of the first transistor above a high level voltage;
- the low level signal lowers the gate voltage of the first transistor below a low level voltage;
- the adjustable range of the gate voltage is between the high level voltage and the low level voltage.
A driving control circuit for a light-emitting device to generate a high-speed modulated current to drive the light-emitting device, comprising:
- an adjustable gain circuit for receiving a digital signal and generating a output voltage controlled by a first control signal and a second control signal;
- a current output circuit comprising a first transistor, wherein a gate of the first transistor is coupled to the adjustable gain circuit, and the adjustable gain circuit adjusts a range of the gate voltage to generate the high-speed modulated current;
- and
- a level control circuit for setting a voltage of the first control signal and a voltage of the second control signal, the level control circuit comprising:
- a level detect circuit coupled to the adjustable gain circuit and generating a first output current and a second output current;
- a first negative feedback current for setting the first current equal to a first predetermined current and outputting a voltage to set a voltage of the first control signal;
- and
- a second negative feedback current for setting the second current equal to a second predetermined current and outputting a voltage to set a voltage of the second control signal;
- wherein the adjustable range of the gate voltage is between a high level voltage and a low level voltage.
Dependencies are inferred from the claim text.