Hewlett-packard Company

Agilent Technologies, Inc.

Hewlett-packard Corporation

Other

Charles S Stephens

Gregory J May

Dennis J Schloeman

David A Williams

Masahiko Muranami

Daniel C Rudolph

Terry G Bradley

Preston D Brown

Daniel I Croft

Tuan Tran

Curtis Rose

Randy W Hergett

An application specific integrated circuit, for use with a circuit having a particular electrical characteristic, e.g. ringing or impedance, has an output pad with an output transistor having a drain connected to the output pad and a gate connected to the drain of a predriver transistor. A predriver time constant is derived from the gate-source capacitance of the output transistor and resistance of the predriver transistor. The predriver time constant is above a selected threshold based on the electrical characteristic such that the predriver transistor is operable to switch the output transistor at a sufficiently slow rate to avoid ringing.

Integrated circuit assembly having output pads with application specific characteristics

An application specific integrated circuit for use with a circuit having particular electrical characteristic such as ringing or impedance. The circuit has an output pad with an output transistor having a drain connected to the output pad, and a gate connected to the drain of a predriver transistor. The output transistor has a gate-source capacitance characteristic, and the predriver transistor has a predriver time constant above a selected threshold based on the electrical characteristic. The first predriver transistor also has a selected resistance based on the predriver time constant and the gate-source capacitance characteristic, such that the first predriver is operable to switch the output transistor at a sufficiently slow rate to avoid ringing.

Integrated circuit assembly having output pads with application specific

A docking station for a portable computer includes a wireless transceiver for wireless communication with the portable computer. The docking station also includes a plurality of ports. Each port includes a physical connector for connection to, for example, one or more peripheral devices, a network or a monitor. A translation manager within the docking station manages translation of information transferred between the wireless transceiver and the plurality of ports.

Docking station for docking a portable computer with a wireless interface

A battery pack, adapter and integrated charging system for charging a battery pack of the type used in a portable electronic device such as a notebook computer, a cellular telephone, etc. The battery pack includes a battery coupled through a power converter to a secondary transformer winding. A communication link is provided to the adapter which includes control logic and a power selector. The adapter may be configured to provide DC or AC power to charge a portable electronic device and the processor of a portable electronic device may be used to control charging of an external battery pack.

Battery pack and charging system for a portable electronic device

A battery charger is connected to a power source via an input cable. The battery charger has charge switching circuitry for delivering a charge to a battery under the control of a controller. The controller has state detection logic for detecting the current state of the battery, and charging logic for charging the battery by selectively enabling and disabling the charge switching circuitry based on the condition of the battery. An output cable is connected to the battery charger. The output cable delivers power from the power source to a second battery charger for charging a second battery for the electronic device. The output cable can be placed in a stowage position or a non-stowage position. The second battery charger may be external or internal to the electronic device. If the second battery charger is internal to the electronic device, two batteries can be charged at the same time the electronic device is being operated. The battery charger has the additional capability of detecting and correctly charging different battery types, and responding to error conditions detected during the charging operation.

Portable battery charger with integrally attached output cable

A common dictionary definition of a 'diode' is 'any electronic device that restricts current flow chiefly to one direction.' This definition covers not only the conventional two lead PN junction semiconductor device presently known in the prior art (referred to herein as a 'conventional diode') but also the electronic device of this invention (referred to herein as a 'low power diode'). A low power diode has a comparator for comparing the voltage present at the anode and cathode of the diode. When the comparator determines that the voltage present at the anode of the low power diode equals or exceeds the voltage present at the cathode of the low power diode by a predetermined forward voltage, a signal is generated. This signal turns on a transistor acting as a switch, which in turn electronically connects the anode and the cathode of the low power diode together. Unlike conventional diodes that have a forward voltage (dependent on the physical silicon junction property of the diode) of approximately 0.7 Volts, this low power diode has a very small forward voltage (dependent on the drain to source resistance of the switch when on and the offset of the comparator) as low as 0.25 milliVolts.

Low power diode

The cell type (i.e. alkaline, Ni-Cd, etc.) of a battery is determined by reference to characteristics of its electrical behavior during charging. Exemplary characteristics include the magnitude of the initial voltage rise and the rate of initial voltage rise. Depending on the outcome of this determination, the charging conditions can be changed (e.g. the charging current can be interrupted if the cell is determined to be a non-rechargeable type). The invention finds particular utility in connection with electronic products such as calculators and portable computers.

Cell type determination of battery under charge conditions

The cell type of a battery is determined by characterizing the series resistance behavior of various cell types to determine ranges of series resistance values exhibited by batteries of a particular cell type. The series resistance of a battery of unknown cell type is then measured. If the series resistance measurement is determined to be within a range of series resistance values exhibited exclusively by a cell type, the battery is identified as having that cell type. However, for batteries whose series resistance measurements are within a non-exclusive range of series resistance values, a second cell type discharge characteristic such as battery voltage is also characterized to differentiate between the cell types. The second discharge characteristic of these batteries is also measured and used to identify the cell type.

Method and apparatus for differentiating battery types

A circuit topology useable in a battery impedance tester to latch a source current to a constant magnitude includes an inductor, a comparator, a driver and a storage capacitor. The inductor is connected in series with a current path between a source and a load. The inductor produces a voltage drop that changes with current drawn by the load. Responsive to the voltage drop, the driver provides the load with current supplied from the storage capacitor. The current provided by the driver returns the source current to the constant magnitude.

Growing community of inventors

Corvallis, OR, United States of America

Charles S Stephens