System and method for using an output transformer for packaged laser diode drivers
Granted: February 21, 2006
Patent Number:
7003007
A laser diode driver output stage for driving an associated laser diode device. In one aspect of the present invention, the laser diode driver output stage includes a driver circuit having at least one input node and an output node. The driver circuit is adapted to receive an input data signal at the at least one input node and provide an output signal at the output node in response to the data signal. The laser diode driver output stage further includes a transformer connected to the…
Multichannel high resolution segmented resistor string digital-to-analog converters
Granted: February 7, 2006
Patent Number:
6995701
Multi-channel high resolution segmented resistor string digital-to-analog converters (DACs) suitable for realization in a single integrated circuit. The DACs incorporate a primary resistor string shared by all channels, and one or more additional pluralities of additional resistor strings for additional resolution. The primary resistor string may be buffered to limit the effect of loading thereon by the plurality of resistor strings coupled thereto. Current sources may also be coupled to…
Apparatus and method for a low-rate data transmission mode over a power line
Granted: January 10, 2006
Patent Number:
6985072
In one embodiment, a system and method for receiving information over a power line in accordance with the HomePlug specification is described. The receiver side of the method involves separation of the data within a payload of an incoming frame into a plurality of blocks. Thereafter, both frame control symbols and data within the blocks are processed by Frame Control Forward Error Correction (FEC) decoding logic.
Blind channel estimation and data detection for PSK OFDM-based receivers
Granted: January 3, 2006
Patent Number:
6983029
In general, one embodiment of the invention relates to a method for detecting data bits and estimating the channel reliability of each carrier. The detection method comprises (i) computing a complex phase difference between a current symbol and a previous symbol, (ii) separating a real value component (R) from a corresponding imaginary value component (I) forming the complex phase difference, (iii) determining at least one boundary constraint line of a complex phase map for a selected…
Wide band digital to analog converters and methods, including converters with selectable impulse response
Granted: December 20, 2005
Patent Number:
6977602
Wide band CMOS digital to analog converters (DACs), including converters with selectable impulse response, using multiple DAC cores. The DAC cores operate on the same data at the DAC clock rate, but staggered in phase. Switches are used to switch the later part of the output time of each DAC core to the DAC output, otherwise to a dummy load. Thus each DAC conversion is comprised of a later part of each DAC core conversion, at least the first part of each DAC core conversion being ignored…
Narrowband interference canceller for wideband communication systems
Granted: December 13, 2005
Patent Number:
6976044
A method and apparatus for adaptively removing interference from a signal. In one embodiment, the invention comprises an infinite impulse response (IIR) notch filter configured to receive a wideband signal and provide a filtered output signal, and a controller coupled to the notch filter to adaptively control the null frequency of the notch filter thereby removing narrowband interference from the received wideband signal. The controller may employ a gradient-based algorithm to detect the…
Low temperature coefficient input offset voltage trim with digital control
Granted: November 22, 2005
Patent Number:
6967526
Low temperature coefficient input offset voltage trim with digital control for bipolar differential transistor amplifiers. The differential input pair of transistors are biased with a current proportional to absolute temperature. Trim current components are generated which also are proportional to absolute temperature and selectively coupled to at least one of the resistive loads to compensate for the original input offset. Control of the coupling of the trim current components…
Method of removing a sacrificial emitter feature in a BICMOS process with a super self-aligned BJT
Granted: November 8, 2005
Patent Number:
6962842
A method of removing a sacrificial emitter feature in a bipolar complementary metal oxide semiconductor (BICMOS) process with a super self-aligned bipolar junction transistor (BJT) is disclosed. According to the new method, a mask layer, such as an oxide deposited using high density plasma (HDP) techniques, is deposited over an extrinsic base layer and over a sacrificial emitter structure. Because of the particular characteristic of the HDP oxide, the deposition of HDP oxide forms a…
System and method for using an output transformer for laser diode drivers
Granted: August 16, 2005
Patent Number:
6931040
A laser diode driver output stage for driving an associated laser diode device. The laser diode driver output stage includes a driver circuit adapted to receive an input data signal at an input node and provide an output signal to a positive output node and a negative output node in response to the data signal. The laser diode driver output stage further includes a transformer having a positive terminal of a first side coupled to the positive output node of the driver circuit, a negative…
Current steering digital-to-analog (DAC) converter with improved dynamic performance
Granted: August 9, 2005
Patent Number:
6927714
A current steering digital-to-analog (DAC) having improved dynamic performance and output signal quality (i.e. improved SFDR characteristic). The DAC includes current steering segments each having differential transistors to steer a current from a summing node to either the positive or negative output. The DAC further comprises a control circuit to reduce the variation of the voltage present at each summing node. More specifically, the control circuit includes a first circuit that…
Metal trim mirror for optimized thin film resistor laser trimming
Granted: July 19, 2005
Patent Number:
6919984
A device and a method of forming the device are disclosed. The device includes a reflector, a first dielectric layer disposed on the reflector, and a thin film resistor disposed on the reflector. The reflector acts as a barrier between the thin film resistor and an underlying dielectric layer which may have a non-uniform thickness. Thus, the thickness control and uniformity of the dielectric layer underlying the reflector does not affect the laser trimming of the thin film resistor. In…
Enhanced linearity, low switching perturbation resistor strings
Granted: June 28, 2005
Patent Number:
6911896
A resistor string that may have two resistor matrices laid out back-to-back with selected or all nominally equipotential nodes of the two matrices being interconnected. In certain applications, the matrix may have switch connections at each node, with the second matrix being an inactive matrix that may have the same number or different number, typically fewer resistors than the first matrix. In another embodiment, separate matrices may be used, and the inactive matrix may be smaller and…
Wideband symbol synchronization in the presence of multiple strong narrowband interference
Granted: June 28, 2005
Patent Number:
6912262
A method and apparatus for time-shift extraction in a wideband transmitted signal containing strong narrowband interference or noise. The time-shift extraction is based on the time domain and frequency domain relation of symbol misalignment. The invention uses the sign of the product of a recieved signal sample and a reference symbol in the frequency domain to determine the time-shift. It does not rely on the signal magnitude and is therefore less dependent on the signal gain. It also…
Low voltage or'ing circuits and methods with zero recovery time
Granted: May 10, 2005
Patent Number:
6891425
Low voltage drop ORing circuits with zero recovery time and reverse current protection. In use, a MOSFET is coupled between a power supply and a load in a multiple power supply, single load system, or between a power supply and a load in a single power supply, multiple load system, or in both locations in multiple power supply, multiple load systems. A controller senses the current through the MOSFET, and turns the MOSFET off when the current falls below a predetermined threshold…
Current mode current sense circuits and methods
Granted: May 3, 2005
Patent Number:
6888401
Current mode current sense circuits and methods that may provide a current output proportional to the sensed current, and that provide current sensing at a fixed voltage drop. Sensing is by way of a transistor coupled in series with the load, with circuitry clamping the voltage drop across the transistor to a predetermined level, and providing a current output proportional to the current in that transistor. Various embodiments are disclosed, including circuits for high side and low side…
Enhanced method of encoding progressive video sequences when employing interlaced codecs
Granted: May 3, 2005
Patent Number:
6888530
In one embodiment, a method comprises an act of separating a progressive scanned frame into a plurality of fields. The plurality of fields includes at least a first field being a first portion of the progressive scanned frame and a second field being a second portion of the progressive scanned frame. In addition, the method further comprises an act of compressing data associated with the first portion of the progressive scanned frame and the second portion of the progressive scanned…
Frame synchronization technique for OFDM based modulation scheme
Granted: May 3, 2005
Patent Number:
6888790
The present invention relates to the field of communications. The method includes generating a sequence of symbols, the sequence of symbols including preamble symbols and a data symbol. The method further includes receiving the sequence of symbols generated by the transmitter, the receiver including a frame synchronizer logic to perform frame synchronization.
Method of forming a super self-aligned hetero-junction bipolar transistor
Granted: March 1, 2005
Patent Number:
6861324
The present invention provides a method of forming a super self-aligned bipolar transistor with enhanced electrical characteristics. The power gain and frequency response of the transistor are improved by horizontally etching an area for the base region that is wider than the active emitter and collector regions. By removing polysilicon layers within the device, the base region resistance goes down and unwanted capacitive effects are reduced.
Continuous linear regulated zero dropout charge pump with high efficiency load predictive clocking scheme
Granted: February 22, 2005
Patent Number:
6859091
Continuous linear regulated zero dropout charge pump with high efficiency load predictive clocking scheme AND method. The method of pumping charge includes amplifying the difference between a feedback signal from the charge pump output and a reference, and alternately switching between: a) coupling a first flying capacitor between first and second power supply terminals, and coupling a second flying capacitor between the amplified difference and the charge pump output; and b), coupling…
Controlling modulation and bias of laser drivers
Granted: February 22, 2005
Patent Number:
6859473
A method for controlling a modulation current and a bias current of a laser driver includes generating a differential signal that has a voltage offset, for setting the modulation current, over a pair of differential inputs from a pre-driver circuit to a laser driver circuit. A voltage is generated for setting the bias current over a bias/monitor pin from the pre-driver circuit to the laser driver circuit. The voltage offset is sensed at the laser driver circuit and the modulation current…
