Granted Patent B2

US 7,609,098 · App. 11/418,205 · Granted Oct 27, 2009

Abstract

Claims (32)

1. A driver circuit for electronic components comprising:

an amplifier;

a control current transistor which generates a control signal from a reference signal;

a driver current mirror;

a control current switch, which is provided between the control current transistor and the driver current mirror, and which selectably isolates the driver current mirror from the control current transistor or connects the driver current mirror to the driver current transistor, the driver current mirror, when in a state connected to the control current transistor, amplifying the control signal into a driver signal; and

a compensating circuit provided between an input of the control current transistor and an input of the amplifier, the compensating circuit permitting compensation of an error current and thereby of a current conversion error of the driver current mirror by generating a correction signal as a function of the error current of the driver current mirror and additively feeding the correction signal into the input of the amplifier.

2. The driver circuit according to claim 1 , wherein a feedback signal input of the amplifier is fed through a feedback path from a feedback signal coupled out of a control branch of the driver current mirror.

3. The driver circuit according to claim 1 , wherein a resistor is provided between an output of the control current transistor and a feed-in of the correction signal.

4. The driver circuit according to claim 1 , wherein the driver current mirror has a control branch with a first transistor and a first emitter resistor, and also has a driver branch with a second transistor and a second emitter resistor,

wherein GD is a conversion ratio, and

wherein a value of the second emitter resistor corresponds to 1/(the conversion ratio GD) times of a value of the first emitter resistor, and an emitter area of the second transistor corresponds to the conversion ratio GD times of an emitter area of the first transistor.

5. The driver circuit according to claim 4 , wherein the compensating circuit has a proportional branch comprising a third transistor, a fourth transistor, a third emitter resistor of the third transistor, and a fourth emitter resistor of the fourth transistor, and wherein an input of the third transistor is connected to an input of the control current transistor.

6. The driver circuit according to claim 1 , wherein a feed-in of the correction signal is provided by an additive combination of the correction signal with the reference signal.

7. The driver circuit according to claim 1 , wherein a feed-in of the correction signal is provided by an additive combination of the correction signal with a feedback signal.

8. The driver circuit according to claim 1 , wherein the driver circuit drives at least one laser diode.

9. The driver circuit according to claim 8 , wherein the laser diode is driven from a cathode side, the cathode side being a low side control.

10. The driver circuit according to claim 8 , wherein the laser diode is driven from an anode side, the anode side being a high side control.

11. A driver circuit for electronic components comprising:

an amplifier;

a control current transistor which generates a control signal from a reference signal;

a driver current mirror;

a control current switch, which is provided between the control current transistor and the driver current mirror, and which selectably isolates the driver current mirror from the control current transistor or connects the driver current mirror to the driver current transistor, the driver current mirror, when in a state connected to the control current transistor, amplifying the control signal into a driver signal; and

a compensating circuit provided between an input of the control current transistor and an input of the amplifier, the compensating circuit generating a correction signal and additively feeding the correction signal into the input of the amplifier

wherein the driver current mirror has a control branch with a first transistor and a first emitter resistor, and also has a driver branch with a second transistor and a second emitter resistor,

wherein GD is a conversion ratio,

wherein a value of the second emitter resistor corresponds to 1/(the conversion ratio GD) times of a value of the first emitter resistor, and an emitter area of the second transistor corresponds to the conversion ratio GD times of an emitter area of the first transistor,

wherein the compensating circuit has a proportional branch comprising a third transistor, a fourth transistor, a third emitter resistor of the third transistor, and a fourth emitter resistor of the fourth transistor, and wherein an input of the third transistor is connected to an input of the control current transistor, and

wherein an emitter area of the third transistor is substantially equal to a quotient of an emitter area of the control current transistor in a numerator and a proportionality factor GC in a denominator, and wherein a value of the third emitter resistor is substantially equal to the proportionality factor GC times an emitter resistor which is connected in series between the control current transistor and a reference voltage connection.

12. The driver circuit according to claim 11 , wherein the fourth transistor has substantially the same conductivity type as the first transistor in the control branch of the driver current mirror, and is dimensioned such that its emitter current density corresponds to an emitter current density of the first transistor.

13. The driver circuit according to claim 12 , wherein the correction signal is provided by a controllable current source that is controlled by a base current of the fourth transistor.

14. The driver circuit according to claim 13 , further comprising a correction current mirror of a transistor diode and at least one additional transistor as controllable current source.

15. The driver circuit according to claim 14 , wherein the correction current mirror scales a current IQM coupled out of a base of the fourth transistor by a factor L and superimposes the current multiplied by the factor L on a feedback signal at a node in the feedback path as a correction signal.

Assignments (11)