Linear Technology Corporation

Other

Motorola Corporation

David B Bell

Robert G Uskali

Samuel Hodson Nork

Roger A Zemke

David McLean Dwelley

Trevor Wayne Barcelo

Wilson D Pace

Edward Lloyd Henderson

David M Dwelley

Matthew E Bell

Dale R Eager

Embodiments of the present invention are generally related to methods and devices for use with vehicles that include a clutch, a transmission, a slave cylinder, a master cylinder and an engine. In accordance with an embodiment, a device includes a primary piston configured to urge hydraulic fluid into a slave cylinder, when the primary piston is moved from a first position to a second position, to thereby disengage the clutch from the transmission. The primary piston is normally movable from the first position to the second position by hydraulic actuation of a master cylinder. A secondary piston is configured to selectively apply force to the primary piston, to move the primary piston from the first position to the second position, when the secondary piston is selectively actuated. The secondary piston can be selectively actuated by a secondary fluid, such as a compressed gas. Methods and devices are used to selectively disengage the clutch from the transmission when an operating condition that can be damaging to the engine is detected.

Systems and methods for selectively disengaging a clutch to protect engines from damage

Novel techniques for balancing current drawn from multiple power supply inputs. A multiple-input inductor is coupled between the power supply inputs and the switching circuits associated with the respective power supply inputs for balancing voltages applied to each of the switching circuits.

Balancing current drawn from multiple power supply inputs using multiple-input inductors

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, such that the sum of load current and battery current is maintained within the programmed current limit.

Current control circuitry and methodology for controlling current from current constrained source

A power management system including a battery-powered application, in which an input current is supplied by a source of current that may be a current-constrained source, such as a USB port, to a battery for charging the battery and to an application load. Battery charging current is supplied to the battery for a period of time based on magnitude of battery charging current, so that charging current of lesser magnitude is applied to the battery for a greater period of time. In accord with one implementation, battery charging current is determined by monitoring the difference between a programmed charging current, dependent on battery type, and magnitude of current used by the load. Change of battery charging current due to voltage mode charging, when charge current begins to drop as the battery approaches full charge, is detected, and in response, the charging period is set to a fixed charging period based on the battery.

Power management circuit and methodology for battery-powered systems

Circuitry and methods are provided for reducing rise time associated with signals on an open-drain or open-collector signal line. Signal line voltage is monitored to determine if the signal line is being pulled LOW. If the signal line is not being pulled LOW, as indicated by signal line voltage exceeding a threshold level, additional pullup current is provided. The additional current may be provided gradually in relation to the signal line voltage, or may be provided in full whenever voltage exceeds the threshold. Circuitry may also be provided to monitor voltage slew rate on the signal line, and to enable the additional pullup current only when the slew rate exceeds a positive threshold level.

Active pullup circuitry for open-drain signals

The present invention enables a pin on an integrated circuit to provide multiple duties. The internal circuit coupled to the selected pin is placed into a high impedance or sampling state based on a recurring signal so that the terminal pin can be sampled. The sampled signal is used to control the operation of the circuit, such as turning off the internal clock to place the circuit in shutdown mode. In that specific example, the integrated circuit exits shutdown mode when the sampled signal changes.

Control feature for IC without using a dedicated pin

The invention provides RF power controllers that cancel offset voltages in the power control loop and external offset voltages by coupling the output of the RF power controller to an auto-zero amplifier during STANDBY mode. The auto-zero amplifier controls the output voltage of the RF power controller during each STANDBY mode so as to eliminate the effect of offset voltages. The voltage at the input of the auto-zero amplifier that allows the offset voltages to be canceled is stored during ENABLE mode. The stored voltage is used by the auto-zero amplifier to continue to remove the effect of the offset voltages on the output voltage of the RF power controller during ENABLE mode. Offset drifts due to temperature, power supply changes, etc. are canceled due to frequent offset sampling.

Offset voltage cancellation system for radio frequency power controllers

Interface circuitry for an integrated circuit is provided, which can operate in accordance with any one of several different protocols. Protocol identifying circuitry within the interface monitors signals passed from a master/host device to the integrated circuit. Based upon the characteristics of the signals, the protocol being used by the master/host device can be determined, and the interface circuitry on the integrated circuit may be configured accordingly. The protocol identifying circuitry 'remembers' which protocol is in use, so that the interface circuit remains configured for the correct protocol regardless of subsequent changes in the signals from the master/host device.

Self-configuring interface circuitry, including circuitry for

Amplifier circuitry is provided having an output voltage range that exceeds its supply rail voltage. Such an amplifier may be useful in battery powered applications calling for driving a high impedance load with a low current, moderate bandwidth signal The amplifier circuitry includes a transconductance amplifier, for providing a high output impedance, and a charge pump DC/DC converter, for providing a high supply voltage to the transconductance amplifier. In one embodiment of the invention, the gain of the amplifier is a function of the input voltage so as to linearize a transfer function between the amplifier input and a response of a load at the amplifier's output.

Amplifier having output range that exceeds supply voltage

A power supply is disclosed for use in battery powered electronic devices. The power supply includes a power source which supplies power to the electronic device itself as well as to battery charging circuitry integral to the power supply. The battery charging circuitry monitors an output current, or other parameter, of the power source output. Feedback circuitry regulates the output of the battery charging circuitry so that output current, or other parameter of the power source output, is kept within predetermined limits.

Battery charging circuitry having supply current regulation

A battery-status-indicating apparatus and arrangement for use-with electronic equipment (100) provides an operator with a displayed indication of remaining battery capacity. A removable battery pack (35) contains memory (37) for storing battery identification information, battery capacity information and a time stamp signal. Electronic circuitry (100), powered by the battery pack (35), maintains current time information and generates the time stamp signal for delivery to said removable battery (35). In addition, the electronic circuitry (100) comprises memory (30) for storing circuit module current draw signals (I.sub.1 -I.sub.4) and battery discharge rate signals (I.sub.5) representative of a discharge rate for different type battery chemistries. A microprocessor (27) containing a real time clock (31) is programmed to determine a battery discharge amount during a time interval (T.sub.5) when the battery is removed from service as well as a battery consumption amount during circuit operation (T.sub.1 -T.sub.4). The microprocessor (27) is also programmed to determine a scaling factor for use in determining a battery consumption amount as multi configuration battery packs (35) are utilized.

Method and apparatus for indicating a battery status

An electronic device (100) is disclosed including an electroluminescent (EL) backlight panel (140) and an EL driver circuit (210). The EL driver circuit (210) provides power to the EL backlight (140), as well as panel aging compensation and user adjustment capabilities. The EL driver circuit (210) is low-cost, small-size, and designed in such a way to be easily integrated into a custom integrated circuit. A method is provided for controlling and converting power to the EL backlight panel (140).

Driver circuit for electroluminescent panel

A full duplex link for sending and receiving digital voice/data signals over a line pair and which incorporates a sample and hold circuit in the receiving portion of the link which is triggered by each change of state of the transmitted signal from the link so that transients resulting from such transmitted signals will not interfere with signals received by the link over the line pair.

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Los Altos, CA, United States of America

David B Bell