Motorola Corporation

National Semiconductor Corporation

Motorola Solutions, Inc.

Other

John Wendell Oglesbee

Michael D Geren

John E Herrmann

Gregory J Smith

William C Bohne

Robert Michael Johnson, Jr

Georgina More

Arthur G Burns

Robert W McGinnis

Joseph Patino

Martin Hague Ramsden

Donald M Archer

Paul Michael Henry

David M Demuro

Upal Sengupta

Philip Henry Burrus, Iv

Ashok Ramakant Patil

Roger L Boyer

Roland Sylvere Saint-Pierre

Dipti V Desai

Chris Hanchana Thongsouk

John E Hermann

Greg J Smith

An intrinsic safety approach is provided for a battery powered communication device. Sparking is prevented at radio contacts during attachment and removal of a battery () from a radio () through the use of switches () to isolate the radio capacitors from the radio contacts and/or dissipate energy from the radio capacitor through a discharge resistor ().

Method and apparatus for intrinsically safe operation of a communication device

Embodiments include a power supply arrangement where major components including an off-line switched power supply are shut off when not in use. When a load is coupled to the power supply arrangement, components are enabled so as to provide power to the load.

Power supply circuit having low idle power dissipation

A system for detecting liquid on a battery or on an electronic device connected with the battery is presented. The battery has an electrical contact for transferring current from the battery to the electronic device. The system includes a sensor for detecting liquid on the battery or on the electronic device and sensor circuitry connected with the sensor. The sensor circuitry prevents current from flowing through the electrical contact of the battery upon detecting liquid.

Immersion sensor to protect battery

A portable radio and battery pack configuration favoring higher available transmit power in explosive atmosphere applications includes a radio device () and a battery pack () removably attached to the radio device. The battery pack includes at least one of an audio power amplifier () and a radio frequency (RF) power amplifier (), and a battery () for supplying power to the radio device and to the at least one of an audio power amplifier and a RF power amplifier.

Portable radio and battery pack configuration

A contactless, inductive charger having a generally planar surface is provided. An image, text or other visual indicator is disposed upon the substantially planar surface such that the visual indicator represents a preferred placement orientation for an electronic device for optimal inductive charging. The charger includes a primary coil positioned within the boundaries of the image, such that a user has a visual guide for placing the device on the charging surface for maximum efficiency in charging. The visual indicator, which may be a picture, outline, text or other directional indicator, may be geometrically similar to a shape of the electronic device or may be in the shape of a generic device. It may be disposed upon the charger by a method selected from the group consisting of painting, molding, silk screening, plating, vapor deposition and adhesive retention.

Contact less charger with alignment indicator

A method for providing cooled flip chip is provided. Solder paste is placed on a back side of a flip chip. A heat sink is placed against the solder paste. The solder paste is reflowed. In addition, an apparatus is provided. Generally, a zener diode flip chip with an active side and a back side opposite the active side and a positive thermal coefficient resistor are provided. A thermally conductive connection is between the positive thermal coefficient resistor and the back side of the zener diode flip chip.

Flip chip mounted to thermal sensing element through the back side of the chip

This invention includes an improvement to a power regulation and thermal management circuit. The power regulation and thermal management circuit includes a pass element coupled serially between a power source and a load. A voltage sensing circuit senses the voltage across the serial element and selects a corresponding current path based upon the sense voltage from a plurality of current paths. The invention includes a timing circuit that periodically, temporarily overrides the selection of current paths. The timing circuit generates a test pulse that temporarily turns all of the current paths on, thereby preventing a discharge lockout condition. The power regulation and thermal management circuit also includes a linear regulator to terminate charging at the appropriate voltage.

Timer circuit and battery protection circuit using same

Voltage regulators are exposed to extreme amounts of voltage over short periods of time during an electrostatic discharge (ESD) event. Shunt regulators require protection from ESD events. Capacitors are passive devices that allow current flow when not in a steady-state condition. An apparatus and method compensates for the extreme voltages inherent in ESD events. By providing capacitance across the gate-drain junction of the shunt device in combination with a gate resistor, a voltage can be applied to the gate of the active device upon commencement of an ESD event, and cause the active device to &ldquo;turn on&rdquo; The &ldquo;turned on&rdquo; active device provides a pathway for the excess voltage from the ESD event to follow and discharge so as to avoid catastrophic failures.

Apparatus and method for improving ESD and transient immunity in shunt regulators

This invention includes a thermally stable, low-cost charging circuit for rechargeable batteries. The circuit includes a thermal control circuit that employs a temperature dependent component such as a thermistor or positive temperature coefficient device. The temperature dependent device is thermally coupled to a charging pass element, which is typically a power transistor. When the transistor enters a danger zone, which is a region of operation characterized by elevated power dissipation in the pass element, the thermal control circuit is actuated to regulate the pass element in a constant power mode until the circuit exits the danger zone.

Thermally limited battery protection and charging circuit

A transient rejecting system for protecting the state of a memory is described. The transient rejecting system includes a signal transfer circuit and a charge storage circuit coupled to at least one pin of a circuit. The signal transfer circuit receives a supply signal and determines when a transient event occurs. When a transient event occurs, the charge storage circuit provides a signal to the pin of the circuit maintaining the state of the memory prior to the transient. During normal operation, the charge storage circuit is charged, and the supply signal is provided to the pin of the memory circuit. P-channel FETs are used in the signal transfer circuit and allow for low voltage operation of the transient rejecting system.

Transient rejecting circuit

This invention includes an improvement to a power regulation and thermal management circuit. The power regulation and thermal management circuit includes a pass element coupled serially between a power source and a load. A voltage sensing circuit senses the voltage across the serial element and selects a corresponding current path based upon the sense voltage from a plurality of current paths. The invention includes a filtering circuit coupled serially between the voltage sensing circuit and the plurality of current paths to reduce noise on the sensed pass element voltage. The power regulation and thermal management circuit also includes a linear regulator to terminate charging at the appropriate voltage. The invention includes a peak detection circuit with the linear regulator to reduce noise caused by, for example, a pulsing load during charging.

Filtering circuit and battery protection circuit using same

This invention provides a means of protecting power dissipating pass elements from exceeding their predetermined thermal limits. In one preferred embodiment, the circuit protects a pass element in a battery charging circuit from exceeding its threshold junction temperature by predicting temperature based upon the voltage across the pass element and the current flowing through it. From this predicted temperature, current is reduced to provide charging of a battery at a constant power. The circuit includes a voltage sensing circuit and a plurality of comparators for selecting a predetermined current based upon the output of the voltage sensing circuit. The circuit provides a piecewise linear approximation of proper pass element voltage and current values to maintain a suitable threshold junction temperature.

Power regulation and thermal management circuit

A method and apparatus provide for improved crowbar protection in a shunt regulator circuit including a shunt device. An over-temperature protection circuit may be combined with a fast-crowbar protection circuit such that maximum protection from damaging thermal energy is provided to a shunt device. The fast-crowbar protection circuit estimates the thermal energy in the shunt device based upon an integration method. By integrating a measured power over time the rise in temperature can be estimated such that the crowbar protection is enabled before the thermal energy can damage the shunt device. The integration method can be approximated using a piece-wise linear approximation such that the estimation circuitry can be simplified. A series of comparators and timing/delay circuits are employed to measure a current level in the shunt device over a given duration. The timing/delay circuits have memory such that heat build up and heat dissipation are modeled.

Apparatus and method for initiating crowbar protection in a shunt regulator

A protection circuit ( ) and protection device ( ) for protecting a rechargeable (lithium-based) battery cell or cells from overcharging. A voltage regulator element ( ) is connected in parallel with the battery cell or cells ( ) and is thermally coupled to a thermal element ( ) connected in series with the charging current supply. The voltage regulator element ( ) prevents overcharging of the battery ( ) by shunting current away from the battery when a predetermined voltage across the battery is exceeded. Moreover, the thermal element ( ) prevents failure of the voltage regulator element ( ) by open circuiting the current path when the heat dissipated by the voltage regulator element ( ), thermally coupled to the thermal element ( ) causes the thermal element to enter a high resistance state. Additional protection may be provided by fuse bonds ( ) connecting the combination of the shunt voltage regulator and the thermal elements ( ) to the charging current supply and to the battery ( ).

Overcharge protection device and methods for lithium based rechargeable batteries

This invention includes a circuit that approximates the thermal behavior of a fuse or other electronic device that is coupled in series with the circuit. In one preferred embodiment, the circuit protects a fuse coupled in series with a rechargeable battery from clearing during soft short conditions. Thus, when the instantaneous current is temporarily above the current rating of the fuse, yet the root mean squared current is below the current rating of the fuse, the circuit works to estimate the heating of the fuse element and limit the current to a root mean squared value that is less than the current rating of the fuse. One embodiment includes a programmable comparator that actuates a counter which, in turn, increments to estimate heating of the element when the current exceeds a predetermined threshold.

Growing community of inventors

Watkinsville, GA, United States of America

John Wendell Oglesbee