Back to results
US 8,971,365 B2Granted
Symmetrical, direct coupled laser drivers
AssigneeMaxim Integrated Products, Inc.
InventorsJames Cong Nguyen, Ashok Kumar Verma
Life of this patent
Estimating the term…
Abstract
Symmetrical, direct coupled laser drivers for high frequency applications. The laser drivers are in integrated circuit form and use a minimum of relatively small (low valued) external components for driving a laser diode coupled to the laser driver through transmission lines. An optional amplifier may be used to fix the voltage at an internal node at data frequency spectrum to improve circuit performance. Feedback to a bias input may also be used to fix the voltage at the internal node. Programmability and a burst mode capability may be included.
Claims23
A laser diode driver comprising:
- a power supply connection, a laser diode anode connection, a laser diode cathode connection, a first bias connection and a circuit ground connection;
- a first inductor coupled between the power supply connection and the laser diode anode connection;
- a second inductor coupled between the laser diode cathode connection and the first bias connection;
- and
- a first capacitor coupled between the first bias connection and the circuit ground connection;
- a first resistor coupled between the power supply connection and the laser diode anode connection;
- a second resistor coupled between the laser diode cathode connection and the first bias connection;
- a current source coupled between the first bias connection and the circuit ground connection;
- first and second transistors, each having first, second and third terminals wherein the voltage between the first and second terminals controls the conduction between the third and first terminals, the first and second transistors having their first terminals coupled together and to the circuit ground connection, the third terminal of the first transistor being coupled to the laser diode anode connection, the second terminals of the first and second transistors being coupled to a first differential voltage source responsive to differential data inputs to controllably turn on either of the first and second transistors as a current source of a first differential current source and to turn off the other of the first and second transistors as defined by the differential data inputs;
- the extent to which the differential data inputs turn on either of the first and second transistors as a current source of the first differential current source and to turn off the other of the first and second transistors as defined by the differential data inputs is programmable;
- the second transistor having its third terminal coupled to the laser diode cathode connection.
8 more elements
A laser diode driver comprising:
- a power supply connection, a laser diode anode connection, a laser diode cathode connection, a first bias connection and a circuit ground connection;
- a first resistor coupled between the power supply connection and the laser diode anode connection;
- a second resistor coupled between the laser diode cathode connection and the first bias connection;
- a current source coupled between the first bias connection and the circuit ground connection;
- first, second and third transistors, each having first, second and third terminals wherein the voltage between the first and second terminals controls the conduction between the third and first terminals, the first and second transistors having their first terminals coupled together and to the circuit ground connection, the third terminal of the first transistor being coupled to the laser diode anode connection, the second terminals of the first and second transistors being coupled to a first differential voltage source responsive to differential data inputs to controllably turn on either of the first and second transistors as a current source of a first differential current source and to turn off the other of the first and second transistors as defined by the differential data inputs;
- the second transistor having its third terminal coupled to the laser diode cathode connection;
- the third transistor having its first terminal coupled to the third terminal of the first transistor, its second terminal coupled to a second bias connection and its third terminal coupled to the laser diode anode connection, whereby the third terminal of the first transistor is coupled to the laser diode anode connection through the third transistor.
4 more elements
A laser diode driver comprising:
- a power supply connection, a laser diode anode connection, a laser diode cathode connection, a first bias connection and a circuit ground connection;
- a first resistor coupled between the power supply connection and the laser diode anode connection;
- a second resistor coupled between the laser diode cathode connection and the first bias connection;
- a current source coupled between the first bias connection and the circuit ground connection;
- first through fourth transistors, each having first, second and third terminals wherein the voltage between the first and second terminals controls the conduction between the third and first terminals, the first and second transistors having their first terminals coupled together and to the circuit ground connection, the third terminal of the first transistor being coupled to the laser diode anode connection, the second terminals of the first and second transistors being coupled to a first differential voltage source responsive to differential data inputs to controllably turn on either of the first and second transistors as a current source of a first differential current source and to turn off the other of the first and second transistors as defined by the differential data inputs;
- the second transistor having its third terminal coupled to the laser diode cathode connection;
- wherein the current source coupled between the first bias connection and the circuit ground connection comprises:
- the first terminals of the third and fourth transistors being coupled to the circuit ground connection, and the second terminals of the third and fourth transistors being coupled to a second differential voltage source responsive to differential burst enable inputs to controllably turn on either of the third and fourth transistors as the current source of a second differential current source and to turn off the other of the third and fourth transistors as defined by the differential burst enable inputs, the fourth transistor when on, acting as the current source coupled between the first bias connection and the circuit ground connection.
5 more elements
A laser diode driver comprising:
- a power supply connection, a laser diode anode connection, a laser diode cathode connection, a first bias connection and a circuit ground connection;
- a first resistor coupled between the power supply connection and the laser diode anode connection;
- a second resistor coupled between the laser diode cathode connection and the first bias connection;
- a current source coupled between the first bias connection and the circuit ground connection;
- first, second and third transistors, each having first, second and third terminals wherein the voltage between the first and second terminals controls the conduction between the third and first terminals, the first and second transistors having their second terminals coupled to be responsive to differential data inputs to controllably turn on either of the first and second transistors as a current source of a first differential current source and to turn off the other of the first and second transistors as defined by the differential data inputs;
- the first transistor having its third terminal to the anode connection and the second transistor having its third terminal coupled to the laser diode cathode connection;
- the third transistor having its first terminal coupled to the third terminal of the first transistor, its second terminal coupled to a second bias voltage and its third terminal coupled to the laser diode anode connection, whereby the third connection of the first transistor is coupled to the anode connection through the third transistor.
4 more elements
A laser diode driver comprising:
- a power supply connection, a laser diode anode connection, a laser diode cathode connection, a first bias connection and a circuit ground connection;
- a first resistor coupled between the power supply connection and the laser diode anode connection;
- a second resistor coupled between the laser diode cathode connection and the first bias connection;
- a current source coupled between the first bias connection and the circuit ground connection;
- first through fourth transistors, each having first, second and third terminals wherein the voltage between the first and second terminals controls the conduction between the third and first terminals, the first and second transistors having their second terminals coupled to be responsive to differential data inputs to controllably turn on either of the first and second transistors as a current source of a first differential current source and to turn off the other of the first and second transistors as defined by the differential data inputs;
- the first transistor having its third terminal to the anode connection and the second transistor having its third terminal coupled to the laser diode cathode connection;
- wherein the current source coupled between the first bias connection and the circuit ground connection comprises:
- the first terminals of the third and fourth transistors being coupled to the circuit ground connection, and the second terminals of the third and fourth transistors being coupled to differential burst enable inputs to controllably turn on either of the third and fourth transistors as the current source of a second differential current source and to turn off the other of the third and fourth transistors as defined by the differential burst enable inputs, the fourth transistor when on, acting as the current source coupled between the first bias connection and the circuit ground connection.
5 more elements
Dependencies are inferred from the claim text.