Texas Instruments Incorporated Deutschland, Gmbh

Texas Instruments Corporation

Andreas Bock

Oliver Piepenstock

Dirk Muentefering

Bhavesh G Bhakta

Frank Gelhausen

This disclosure describes techniques for shifting the cross-point of a digital signal in an optical transmitter. The cross-point shifting techniques may use multiple differential transconductors with their common polarity outputs coupled together to shift the cross-point of a signal. Using multiple differential transconductors in this manner may increase the balance between the positive and negative polarities of the resulting cross-point shifted signal relative to other types of cross-point shifting techniques, which may improve the quality of an optical signal generated by an optical transmitter.

Cross-point shifting techniques

An integrated circuit (IC) for driving a light emitting semiconductor device is provided. The IC includes an input stage configured to receive a first input signal with a first differential pair of bipolar transistors and a second input signal with a second differential pair of bipolar transistors and to provide a pre-driver output signal being a superposition of the first input signal and the second input signal and an output stage including a third differential pair of bipolar transistors for receiving the pre-driver output signal of the input stage and for driving the light emitting semiconductor device in response to the pre-driver output signal, wherein the IC is configured to pre-distort the pre-driver output signal of the input stage so as to compensate a signal distortion of the output stage.

CML output driver

A buffer is provided. The buffer includes a first switch and a second switch coupled in series at a first output node, a third switch and a fourth switch coupled in series at a second output node, a first current source and a second current source. The first current source is coupled with one side to the first switch and the third switch and with another side to a first supply voltage, the second current source is coupled with one side to the second switch and the fourth switch and with a second side to a second supply voltage. The first current source is configured to adjust an output swing in a first operation mode and in a second operation. The second current source is configured to adjust a common mode voltage level of the output signal in the first operation mode and to provide maximum series resistance in the second operation mode.

Electronic device and method for buffering

Here, a driver for an light emitting diode (LED) is provided. Within this driver, several differential pairs of bipolar transistors are employed in an input stage and output stage along with a control loop. Collectively, these components operate together to drive the LED with a low headroom voltage while still achieving high driver performance in terms of edge speed and jitter.

Apparatus and method for driving an LED

An RSS indicator with a linear characteristic that is of a simple configuration, low current consumption and small die area requirements, comprises a pair of input transistors with coupled emitters and base electrodes to which an input signal is differentially applied. Each of the input transistors has a collector load circuit connected between a first supply terminal and its collector, and a tail current sink connected between a second supply terminal and the coupled emitters. The load circuit of each input transistor includes a current source which supplies a current copied from the tail current. A signal strength indicator signal is obtained from a differential signal between corresponding output nodes of the collector load circuits by taking the mean value of the differential signal referenced to the first supply terminal.

Integrated low power received signal strength indicator (RSSI) with linear characteristic

A loss-of-signal (LOS) detector includes a variable gain amplifier with an input receiving an input signal, a threshold comparator with a first input receiving a signal derived from an output of the variable gain amplifier, a second input receiving a reference level and an output providing a loss-of-signal indication signal. The variable gain amplifier has a gain control input receiving a gain control signal derived from the output of the threshold comparator and such that the gain of the variable gain amplifier is set to a lower value when the loss-of-signal indication signal is active, and set to a higher value when the loss-of-signal indication signal is not active. Accordingly, the LOS detector needs only one decision level for both of the LOS and NotLOS decisions, which is set in the linear range of the signal detector so that the hysteresis is reproduced precisely.

Growing community of inventors

Isernhagen, Germany

Andreas Bock