Patent application number | Description | Published |
20120018622 | DIFFERENTIAL AMPLIFIER WITH FUNCTION OF VARIABLE GAIN AND OPTICAL RECEIVER IMPLEMENTED WITH THE SAME - A differential circuit with a function of a variable gain without shifting the output cross point is disclosed. The differential circuit includes an amplifying stage and a control stage. The amplifying stage includes three units each having a pair of transistors, a pair of load resistors, and a pair of current sources. The second and third units each put between the first unit and the load resistor to bypass the current. The control stage includes two units and two current sources to compensate the current bypassed by the second or third unit to keep the DC output level substantially in constant. | 01-26-2012 |
20120121273 | COMMON BASE CIRCUIT WITH OUTPUT COMPENSATION, CURRENT-TO-VOLTAGE CIRCUIT CONFIGURED WITH COMMON BASE AMPLIFIER, AND OPTICAL RECEIVER IMPLEMENTED WITH THE SAME - An amplifier implementing with a common base circuit is disclosed. The amplifier includes the common base circuit, a current shunt, and a current supplement. The common base circuit receives an input current. The current shunt shunts the input current based on the average of the output of the pre-amplifier. The current supplement supplements a current shunted by the current shunt. | 05-17-2012 |
20130229699 | DRIVER CIRCUIT CONFIGURED WITH TRAVELLING WAVE AMPLIFIER - A driver with the arrangement of the travelling wave amplifier is disclosed. The driver provides n counts of cells each configuring the open collector arrangement and amplifying an input signal. The cells are arranged between an input interconnection and an output interconnection, and powered through the output interconnection. The power supply line to power the output interconnection is connected between m-th and (m+1)-th cells not through the output terminal of the output interconnection. | 09-05-2013 |
20130307619 | TRAVELING WAVE AMPLIFIER WITH SUPPRESSED JITTER - A traveling wave amplifier (TWA) with suppressed jitter is disclosed. The TWA includes a plurality of unit amplifiers with the differential arrangement comprised of a pair of transistors and a cascade transistors connected in series to the switching transistors. The unit amplifiers further includes current sources to provide idle currents to the cascade transistors. Even when the switching transistors fully turn off, the idle currents are provided to the cascade transistors, which set the operating point of the cascade transistor in a region where an increase of the base-emitter resistance is suppressed. | 11-21-2013 |
20140132348 | Differential Amplifier - A differential amplifier with cascade transistors connected in series to switching transistors is disclosed. The base bias of the cascade transistors is set higher than the output LOW level of the cascade transistor by a preset amount of 0.1 to 0.2V, or lower than the input HIGH level of the switching transistor by the preset amount adding to a forward voltage of a junction diode, to provide a discharge current of the base-emitter junction Cbe from the bias control, or from the upstream stage to drive the differential circuit. | 05-15-2014 |
20140233083 | DRIVER FOR ELECTRO-ABSORPTION MODULATOR - A transmitter optical module implemented with an electro-absorption (EA) modulator is disclosed. The module includes an EA driver comprising a signal detector, an offset controller, and a driver circuit. The signal detector detects the existence of the modulation signal input thereto. The offset controller provides to the driver circuit the first offset to shift the cross point of the output of the driver circuit higher when the modulation signal exists; while, the second offset when the modulation signal disappear. The second offset lowers the output of the driver circuit to prevent the excess optical output of the transmitter optical module. | 08-21-2014 |
20140333374 | TRAVELLING WAVE AMPLIFIER PROVIDING CASCADE UNITS EACH INCLUDING DYNAMIC CASCADE TRANSISTOR WHOSE COLLECTOR OUTPUT FED-BACK TO BASE INPUT - A traveling wave amplifier including differential circuits to suppress the backward wave effect is disclosed. The differential amplifier includes two cascade units providing a switching transistor, a static cascade transistor, and a dynamic cascade transistor connected in series. The dynamic cascade transistor provides a feedback circuit to feed the collector output to the base input thereof through a resistive divider in lower frequencies and a capacitive divider in high frequencies. | 11-13-2014 |
20150084674 | DETECTION CIRCUIT FOR DETECTING SIGNAL AMPLITUDE - A detection circuit includes a differential circuit including a pair of differential transistors configured to receive the input differential signal and a first current source, the pair of the differential transistors having a common output terminal connected to the first current source, a hold capacitor connected between the common output terminal and a reference potential for generating a hold potential, a level sensing circuit configured to sense a voltage level of the input differential signal and output a switching signal, and a switch configured to receive the switching signal and electrically connect the common output terminal and a second current source when the switching signal exceeds a threshold level being lower than the hold potential by a predetermined amount, and electrically disconnect the common output terminal and the second current source when the switching signal stays lower than the threshold level. | 03-26-2015 |