Controlling power distribution among multiple wires in communication cable
Granted: November 2, 2010
Patent Number:
7827418
A novel system and methodology for supplying power over a communication cable, such as an Ethernet cable, using power distribution circuitry for controlling power distribution between wires or pairs of wires in the communication cable. The power distribution circuitry may control distribution of current among wires or pairs of wires in the communication cable. In particular, balance of current among the wires or pairs of wires may be provided.
Advanced current-mode control for switched regulators
Granted: October 12, 2010
Patent Number:
7812585
A voltage regulator includes an input connectable to a voltage source and an output connectable to a load. The voltage regulator includes an inductor coupled to the output, a switch between the input and the inductor, and a current control loop configured to control the duty cycle of the switch to regulate voltage at the output, wherein the duty cycle being based on both a peak and valley threshold level of current flowing through the inductor.
Power management mechanism in system for supplying power over communication link
Granted: October 12, 2010
Patent Number:
7814340
System and methodology for managing power supplied to powered devices over communication links, such as Ethernet links. A power supply system has multiple power supply ports for providing power to respective powered devices via multiple communication links. A power-in-use bus shared by the multiple power supply ports is configured for receiving a power-in-use signal representing total amount of power being used by the powered devices. Multiple port control circuits associated with the…
Multiple output amplifiers and comparators
Granted: September 28, 2010
Patent Number:
7804286
An amplifier/comparator includes a multitude of output stages all sharing the same input stage. One or more of the output stages are amplification stages and have compensated output signals. A number of other output stages are not compensated and provide comparison signals. Each uncompensated output stage is adapted to switch to a first state if it detects a first input signal as being greater than a second signal, and further to switch to a second state if it detects the first input…
Determining average output current in DC-DC converter
Granted: September 14, 2010
Patent Number:
7795846
A switching circuit for converting an input voltage into an output voltage has an input terminal for receiving the input voltage. A power switching element is coupled to the input terminal and has duty cycle d controllable to adjust the output voltage with respect to a desired level using inductor current representing current in an inductor element connectable to the power switching element. An average and hold circuit is responsive to a voltage at an output of the power switching…
Apparatus and method for producing signal conveying circuit status information
Granted: August 24, 2010
Patent Number:
7782017
Apparatus is configured for producing an output signal indicating an operating status of a monitored circuit. An input signal relating to the monitored circuit is received at an input node. A pulse train generator, coupled to the input node, is configured for generating a pulse train of a prescribed repetition rate at a duty cycle alternated between first and second duty cycle values at a prescribed frequency. The duty cycle and frequency are indicative of operating status of the…
Switching battery charger with programmable current control and power control
Granted: August 17, 2010
Patent Number:
7777455
A switching circuit coupled to one or more input sources and having one or more switching elements controlled to produce an output for charging a battery. A first control circuit is responsive to current of the switching circuit for producing a first control signal to drive the switching element so as to control the current. A second control circuit is responsive to voltage at the battery for producing a second control signal to drive the switching element so as to control voltage…
Low thermal hysteresis bandgap voltage reference
Granted: August 10, 2010
Patent Number:
7772920
A first and a second group of individual transistors in a voltage reference may collectively function as a first and a second composite transistor with a first and a second emitter area equal to the combined areas of the emitters of the first and the second groups of individual transistors, respectively. The second emitter area may be larger than the first emitter area. The stability of the reference voltage may depend upon the stability of the ratio between the first emitter area and…
Single-wire sequencing technique
Granted: July 27, 2010
Patent Number:
7765420
Novel system and protocol for controlling a sequence of events. The sequencing system has a master circuit for providing sequencing information defining a sequence of events using a sequencing signal, and at least one slave circuit responsive to the sequencing signal for producing at least one event signal defining an event. The master and slave circuits are configured for providing a bidirectional transfer of the sequencing information via a single wire.
Circuit and methodology for supplying pulsed current to a load, such as a light emitting diode
Granted: June 29, 2010
Patent Number:
7746300
A circuit for controlling pulsed current to a load, one application of which is in LED dimmer circuitry, comprises first and second reference nodes for receiving a supply voltage, an input node for receiving a timing signal such as a PWM signal, and a controlled switch coupled between the first and second reference voltage nodes for supplying current to the load. Pull-up circuitry may be coupled between a control electrode of the controlled switch and first reference voltage node, and a…
Current control circuitry and methodology for controlling current from current constrained source
Granted: June 8, 2010
Patent Number:
7733061
Current control circuitry for controlling current supplied from a source, that may be a current-constrained source, to a load and a battery. A current limit control circuit limits current supplied by the source to the load in accord with a programmed current limit. Load current is measured, and an input charger control circuit controls magnitude of current to the battery based on the difference between measured load current and battery current programmed to be supplied to the battery,…
Programmable conduction mode control for switching circuits
Granted: June 8, 2010
Patent Number:
7733672
A control system that controls a switching circuit having a switching element and an inductive element coupled to an output of the switching element. The control system includes a switching control circuit that controls the switching element to operate the switching circuit in a first conduction mode of operation, such as a boundary conduction mode (BCM), in which current in the inductive element is maintained at a non-zero level during a first time period within each switching cycle. A…
System and method for tracking a variable characteristic through a range of operation
Granted: May 11, 2010
Patent Number:
7714550
An analog control circuit is coupled to an apparatus having a variable characteristic over an operating range. A sensing circuit is coupled to the apparatus and the control circuit during the range of operation of the apparatus and is operative to sense the variable characteristic. The operating parameter of the apparatus is controlled to be set at a level corresponding to a prescribed criterion, which may be a maximum or minimum, of the characteristic sensed over the range of operation.
Method and system for variable-gain amplifier
Granted: May 11, 2010
Patent Number:
7714658
Method for a variable-gain amplifier (VGA). A plurality of attenuator nodes is serially connected via a first set of resistors between adjacent attenuator nodes to form an attenuator ladder and coupled to an AC input of the variable-gain amplifier. Each of the attenuator nodes includes a transistor and an RC circuitry that couples drain, gate, and source terminals of the transistor to a control signal for the attenuator node. The VGA also includes an amplifier that has an output produced…
Dual-input DC-DC converter with integrated ideal diode function
Granted: May 4, 2010
Patent Number:
7709976
Novel system for supplying power from multiple power sources to a powered device has first and second input power supplies for respectively providing power from first and second power sources. An input selector circuit is responsive to the first and second input power supplies for producing an input power supply signal provided to a power regulator, such as a DC-DC converter, for generating a regulated output power supply signal. The power regulator includes a first transistor device…
Power manager and power managing method for battery-powered application
Granted: May 4, 2010
Patent Number:
7710079
A power manager is configured to manage power for a battery-powered application. A power source, a load and a battery are interconnected through a circuit path. Power from the power source is provided to the load and battery by a switching regulator. Various implementations are presented.
DC/DC converter with current limit protection
Granted: May 4, 2010
Patent Number:
7710700
A converter coupled to a DC voltage input and connectable to a load, includes a signal responsive switch coupled between a first circuit point and a second circuit point. Current flow is directed by the switch, when in a closed state, to the second circuit point to bypass the load. A regulator circuit has an output coupled to a control input of the switch. The regulator circuit has a first input for receiving a sensed load parameter, a second input for receiving a sensed current level…
Multi-input power supply supervisor
Granted: May 4, 2010
Patent Number:
7711971
A system for monitoring multiple power supply signals with respect to a threshold has multiple inputs for receiving input power supply signals. A processing circuit of the system produces an output signal at a first level when the power supply signals have a prescribed relationship to a threshold value, and produces the output signal at a second level when at least one of the input power supply signals does not have the prescribed relationship to the threshold value. The processing…
Systems and methods for characterizing component ratios and generating a digital representation of same
Granted: April 27, 2010
Patent Number:
7705765
Circuits and methods for determining component ratios are provided. An analog to digital converter circuit may include comparison capacitors arranged in an upper group and a lower group for quantizing analog signals into the digital domain. In addition to determining the lower bits during an analog to digital conversion of an input sample, the lower group of comparison capacitors may also be used during calibration mode to quantize a ratio signal that represents the capacitor mismatches…
Combination of high-side and low-side current control in system for providing power over communication link
Granted: April 20, 2010
Patent Number:
7702302
A novel system for supplying power to a powered device over a communication link, such as an Ethernet link, has a current control mechanism that combines low-side current control circuitry with high-side current control circuitry. The low-side current control circuitry is coupled to a low-side power supply line for controlling low-side current flowing in the low-side power supply line. The high-side current control circuitry is coupled to a high-side power supply line for controlling…
