Dallas Semiconductor Corporation

Brian W Jones

Alan M Morton

Scott E Jones

Ronald W Pearson

An apparatus for monitoring the condition of a battery. The apparatus includes a battery clip that is used to secure a battery to a battery connection and a battery monitoring IC. The battery monitoring IC takes a &ldquo;load vs. no-load measurement&rdquo; and the results are recorded in a register. When the battery reaches a certain low voltage state, register bits are set and an output is generated. Furthermore, the exemplary embodiment includes a removal detection circuit for detecting removal and replacement of the battery and for preventing voltage floating on the battery output line.

Battery monitoring system with integrated battery holder

A programmable power controller controls power between a primary power source and a secondary power source and powering first circuitry. The primary power source has a first voltage and the secondary power source has a second voltage. A control register has a first field, which is field used to activate circuitry used to direct power from the primary power source to the secondary power source. First logic circuitry compares the first voltage and the second voltage to determine which is greater and then couples the primary power source or the secondary power source, depending upon which is greater, to power the first logic circuitry, second logic circuitry, and memory. The memory is coupled to the first logic circuitry and is read and written to via an input/output buffer. The second logic circuitry is coupled to the memory and to said first logic circuitry and activates write protection circuitry to prevent writing to the memory if the secondary power source is powering the first logic circuitry, the second logic circuitry, and the memory. A multiple voltage interface system comprises a first voltage interface able to be electrically coupled to first power supply having a first voltage level, a second voltage interface able to be electrically coupled to a second power supply having a second voltage level and switching circuitry to switch said second voltage interface on to receive and adjust said second voltage level to power an application system or to switch said first voltage interface on to receive and adjust said first voltage level to power said application system.

Programmable power supply systems and methods providing a write

A battery management chip which controls charging and discharging currents of a rechargeable battery. Another significant teaching of the presently preferred embodiment is a battery manager integrated circuit which includes an on-chip bandgap voltage reference. The circuitry for bandgap voltage references is conventional, and a variety of circuit configurations are very well-known, but bandgap voltage references normally have a significant power consumption. However, the precise voltage reference derived from such a circuit is extremely useful in performing precise and optimal control of battery function.

Battery management system

A programmable power controller for controlling power between a primary power source and a second power source and powering first circuitry, each of which has a voltage, comprises a control register having a first field, which is used to activate circuitry used to direct power from the primary power source to the second power source, and circuitry to compare the first voltage and the second voltage to determine which is greater and then coupling the primary power source or the second power source depending upon which is greater to power the first circuitry. The control register also has a second field used to select an electrical path having a first voltage drop that ensures the primary power source will have a higher voltage when the primary power source is active under normal operating conditions and a third field used to select an electrical path of a plurality of electrical paths, each electrical path having a variety of voltage drops and resistances. The second power source is preferably chargeable, such as a capacitor or a rechargeable battery.

Programmable power supply system and methods

A programmable power controller controls power between a primary power source and a secondary power source and powering first circuitry. The primary power source has a first voltage and the secondary power source has a second voltage. A control register has a first field, which is field used to activate circuitry used to direct power from the primary power source to the secondary power source. First logic circuitry compares the first voltage and the second voltage to determine which is greater and then couples the primary power source or the secondary power source, depending upon which is greater, to power the first logic circuitry, second logic circuitry, and memory. The memory is coupled to the first logic circuitry and is read and written to via an input/output buffer. The second logic circuitry is coupled to the memory and to said first logic circuitry and activates write protection circuitry to prevent writing to the memory if the secondary power source is powering the first logic circuitry, the second logic circuitry, and the memory.

Battery charging systems

A battery management chip which controls charging and discharging currents of a rechargeable battery. In a portable module, the battery manager chip controls the charging and discharging of the rechargeable battery which powers the whole module, and is therefore connected directly to the battery and to the source of charging current. The chip is also connected to draw very small amounts of current from a third, stable battery, preferably a lithium battery, which is not necessarily rechargeable.

Battery manager chip with connections for redundant backup battery

A battery management chip which controls charging and discharging currents of a rechargeable battery. A further novel teaching set forth in the present application is an integrated circuit which includes a crystal-controlled oscillator for precise time measurement. Crystal-controlled oscillators are normally fairly power-hungry circuits, and such circuits would not normally be used in the low-power part unless needed. However, according to this innovative teaching, the precise time integration provided by the crystal oscillator is significantly advantageous, since it permits accurate time integration to derive the present state of the battery after multiple charge and discharge cycles. In addition, in the presently preferred embodiment, a low-power crystal-controlled oscillator is used.

Battery manager chip with crystal-controlled time base

A battery management chip which controls charging and discharging currents of a rechargeable battery. The chip includes a differential temperature-sensing circuit, for connection to two separate temperature-sensing devices. Thus, one thermistor can be placed in close thermal contact with the casing of the battery, while the other thermistor is exposed to ambient temperature. This permits a temperature rise in the battery to be sensed. This is very useful in controlling charging characteristics. Otherwise, the rate of charging current may be excessive under a low ambient temperature and lower than necessary under high ambient temperature.

Battery manager chip with differential temperature sensing

A RAM-based FIFO which provides self-timing of the data outputs in read mode. When the data output is not valid, the data output drivers are in a high-impedance condition. Therefore, FIFOs using this RAM-based architecture can readily be combined to provide a wider or deeper FIFO, without introducing any additional delay whatsoever. Small differential delays are preferably introduced in the activation of the output buffers, to avoid noise on power supply lines.

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Garland, TX, United States of America

Brian W Jones