Patent application number | Description | Published |
20090189654 | Common-Mode Feedback Method Using a Current Starved Replica Biasing - A method, system, and circuit design product for setting the common-mode voltage level of a charge pump to yield low duty cycle distortion from a voltage controlled oscillator (VCO). Differential charge pumps utilize common-mode feedback (CMF) networks to control the common-mode voltage level. A replica circuit of a current starved delay cell from a VCO replaces the unity gain buffering circuit within a common-mode feedback circuit. Inserting the current starved delay cell replica circuit permits adequate negative feedback compensation, while allowing a phase locked loop (PLL) to operate with a wide bandwidth. As a result of utilizing the replica circuit of a current starved delay cell from a VCO, the common-mode voltage level is optimally centered to interface with the VCO, thereby minimizing duty cycle distortion. | 07-30-2009 |
20090189701 | Single-Ended to Differential Translator to Control Current Starved Delay Cell Bias - A method, system, and circuit device for interfacing single-ended charge pump output to differential voltage controlled oscillator (VCO) inputs to yield low duty cycle distortion from a VCO. A single-ended charge pump output is utilized to create a compliment differential voltage leg, while optimally centering the common-mode voltage level to interface to a current starved ring VCO. A replica of the VCO's current starved delay cell is implemented along with negative feedback to generate the compliment differential voltage leg. The single-ended charge pump output is coupled to a first transistor, while a second transistor is coupled to the output of an error amplifier. The error amplifier utilizes negative feedback to bias the second transistor, forcing the output of the replica circuit to equal a reference voltage. | 07-30-2009 |
20090261890 | REGULATED VOLTAGE BOOST CHARGE PUMP FOR AN INTEGRATED CIRCUIT DEVICE - An apparatus and method for a regulated voltage boost charge pump for an integrated circuit (IC) device. The charge pump generally includes a plurality of switching networks and a lift capacitor that are intermittently coupled to an output capacitor or to a regulating transistor, a differential error amplifier biasing a gate terminal of the transistor, and a controller configured to alternate states of switches in the switching networks in a pre-selected timing relationship with a clock signal of the IC device. | 10-22-2009 |
20100026272 | METHOD AND APPARATUS FOR DISTRIBUTION OF A VOLTAGE REFERENCE IN INTEGRATED CIRCUITS - Inventive embodiments described here provide for accurately distributing a voltage reference to multiple cores of an integrated circuit (IC). A quasi-differential interface is used to transmit the voltage reference, and a virtual ground is established at a receiver located at each core location on the integrated circuit. In one embodiment, the receiver is an operational transconductance amplifier (OTA) that converts a virtual-ground-referenced voltage input to a current. In one embodiment, the OTA converts the virtual-ground-referenced voltage into three currents via three driving current sources operating relative to the virtual ground and the local ground of the core. Negative feedback controls the accuracy of this conversion and provides a way to cancel the effects of the distribution resistance. The current is sourced across the voltage domains between the virtual ground and the V | 02-04-2010 |
20110057727 | ADAPTIVE COMMON MODE BIAS FOR DIFFERENTIAL AMPLIFIER INPUT CIRCUITS - A method and apparatus for extending the common mode range of a differential amplifier. A circuit has a common mode detection circuit, a common mode voltage inversion circuit, and a differential amplifier. The common mode detection circuit receives a differential signal and detects a common mode voltage. The common mode voltage inversion circuit is coupled to the common mode detection circuit. The common mode voltage inversion circuit has an input node that receives the common mode voltage and an output node that outputs body voltage, wherein the common mode voltage inversion circuit creates an inverse relationship between the common mode voltage and the body voltage. The differential amplifier includes a differential pair of transistors that have a pair of body terminals coupled to the output node of the common mode voltage inversion circuit. | 03-10-2011 |
20120153909 | HYBRID FAST-SLOW PASSGATE CONTROL METHODS FOR VOLTAGE REGULATORS EMPLOYING HIGH SPEED COMPARATORS - Voltage regulator circuits and methods implementing hybrid fast-slow passgate control circuitry are provided to minimize the ripple amplitude of a regulated voltage output. In one aspect, a voltage regulator circuit includes a comparator, a first passgate device, a second passgate device, and a bandwidth limiting control circuit. The comparator compares a reference voltage to a regulated voltage at an output node of the voltage regulator circuit and generates a first control signal on a first gate control path based on a result of the comparing. The first and second passgate devices are connected to the output node of the regulator circuit. The first passgate device is controlled in a bang-bang mode of operation by the first control signal to supply current to the output node. The bandwidth limiting control circuit has an input connected to the first gate control path and an output connected to the second passgate device. The bandwidth limiting control circuit generates a second control signal based on the first control signal, wherein the second control signal is a slew rate limited version of the first control signal, and wherein the second passgate is controlled by the second control signal to supply current to the output node. | 06-21-2012 |
20120153910 | DUAL-LOOP VOLTAGE REGULATOR ARCHITECTURE WITH HIGH DC ACCURACY AND FAST RESPONSE TIME - Dual-loop voltage regulator circuits and methods in which a dual-loop voltage regulation framework is implemented with a first inner loop having a bang-bang voltage regulator to achieve nearly instantaneous response time, and a second outer loop, which is slower in operating speed than the first inner loop, to controllably adjust a trip point of the bang-bang voltage regulator to achieve high DC accuracy. | 06-21-2012 |
20120313597 | Wide-Bandwidth Linear Regulator - A linear regulator and a method of regulating a supply voltage are provided. Embodiments include a linear regulator with a first feedback loop and a second feedback loop. The first feedback loop is characterized by a first bandwidth and a first gain. The first feedback loop includes a first amplifier characterized by an output impedance which is significantly reduced in order to maximize the bandwidth of the first feedback loop when driving the capacitance of a control input of a series pass element. The second feedback loop is characterized by a second bandwidth and a second gain. The second feedback loop includes a second amplifier that controls the current in the first amplifier in the first feedback loop. | 12-13-2012 |
20140355661 | DECISION FEEDBACK EQUALIZER ('DFE') WITH A PLURALITY OF INDEPENDENTLY-CONTROLLED ISOLATED POWER DOMAINS - A Decision Feedback Equalizer (DFE) that includes: a plurality of input signal lines comprising at least one data signal line and a plurality of power control signal lines; at least one output signal line; and a plurality of independently-controlled isolated power domains, where each independently-controlled isolated power domain is coupled to a corresponding one of the power control signal lines, each of the power control signal lines configured to transmit a power control signal to the independently-controlled isolated power domain dynamically, and each independently-controlled isolated power domain selectively consumes power in response to the power control signal, each independently-controlled isolated power domain configured to be dynamically powered up or powered down without impacting signal processing operations. | 12-04-2014 |
20140376603 | TESTING A DECISION FEEDBACK EQUALIZER ('DFE') - Testing a Decision Feedback Equalizer (‘DFE’), the DFE including a summing amplifier operatively coupled to a plurality of latches and an input signal line for receiving a data signal, including: preventing a differential data signal from being received by the summing amplifier; and iteratively for each tap to be tested: setting a tap coefficient for each tap to zero; setting an output of the plurality of latches to a predetermined value; setting a tap coefficient for the tap to be tested to a full scale value; and determining whether a resultant output signal from the DFE matches a predetermined expected output signal. | 12-25-2014 |