National Semiconductor Corporation

Fairchild Semiconductor Corporation

Igor Furlan

Gregory J Smith

Vladislav Potanin

Elena Potanina

Yinming Chen

Francisco Javier Guerrero Mercado

Glenn Chance Dunlap, Iii

Jeremy A Carlson

This document discusses, among other things, a multi-address Inter-Integrated Circuit (IC) selection circuit configured to receive a number (N) of identification (ID) signals from a corresponding number (N) of ID pins of a slave IC device and at least one of a data signal from a serial data line (SDA) of an IC bus or a clock signal from a serial clock line (SCL) of the IC bus, and to determine one of 4 to the power of N (4) selectable IC addresses using the number (N) of ID signals and at least one of the data signal or the clock signal. In an example, the multi-address IC selection circuit can determine 4 selectable IC addresses using a single ID signal from a single ID pin of the slave IC device.

Pin selectable I2C slave addresses

A method and circuit for adjusting a safety time-out in charging devices based on a charge current. According to one embodiment, a signal that is based on the charge current is employed to control an output of an oscillator, which controls an operation of a safety timer circuit. The safety timer circuit activates or deactivates a voltage-current (V-I) control loop of the charging device providing the safety time-out based on the charge current. In another embodiment, where a digital current-set circuit may be employed to determine a value of the charge current, a Digital-to-Analog Converter (DAC) may provide the charge current limit to the V-I control loop, and another output of the digital current-set circuit may control the safety timer. In a further embodiment, a signal based on the charge current may be digitized and employed to control the safety timer comprising a time-out counter.

Circuit and method for adjusting safety time-out with charge current

A regulator is provided. In one embodiment, the regulator operates as follows. During steady-state conditions, the switching frequency is maintained substantially constant. During start-up and/or in response to an over-current event, the reference voltage is attenuated. For example, in one embodiment, during a soft-start, the reference voltage ramps upward. During the soft-start, the switching frequency is attenuated in proportion to the attenuation of the reference voltage. The switching frequency is attenuated by skipping a number of pulses that is proportional to the reference voltage attenuation, or through another method. In another embodiment, a dynamic over-current protection scheme is employed.

Apparatus and method for start-up and over-current protection for a regulator

A method for communicating with portable device batteries is described. Many portable devices such as cellular phones may employ a wide variety of batteries with different types, capabilities, and the like. Batteries may be retrofitted with additional circuitry that is arranged to provide information about the battery such as capacity, type, charging status, and the like to the portable device. However, additional pins for communication between the battery and the portable device may increase manufacturing cost, reduce reliability, and the like. In addition, many batteries nowadays have a resistor between their ground pin and temperature sense pin that may be used for sensing temperature of the battery as well as providing battery type information to the portable device. The present invention employs a one wire transceiver using the existing temperature sense pin and the resistor, thereby allowing additional information exchange with the battery without increasing manufacturing cost or reducing reliability.

Battery temperature sensor pin used as communication channel

The present invention is directed at providing methods in a circuit for smoothing transitions relating to a signal processing function. A reference signal is produced that relates to a DAC output code. The reference signal is used as a starting point, and is compared to the input signal. A feedback signal is produced that is used to adjust the reference. The invention can be used to implement signal processing functions such as peak detection, noise filtering, peak suppression, and the like, in which the transitions in the signal are smoothed. The invention can implement these functions with a minimal complexity and a minimal die area.

Method to smooth transitions in an ADC for current regulation

The present invention provides a redundant break before make digital circuit. Redundant circuits are used to provide a path to ground for a charging signal when a fault condition exists. The fault condition may be based on characteristics relating to the signal or the chip itself. For example, a fault condition may occur when a temperature measured on the chip exceeds a predetermined threshold. A fault condition may also occur when the signal is above or below a predetermined threshold. For example, a fault condition may occur when the current of the signal is above a predetermined level. The fault conditions are monitored and the state of a switch that couples the cell to the charging path is monitored. When the switch is open and a fault condition has occurred, there are redundant paths to ensure that a switch closes to provide the path to ground during the fault condition.

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Sunnyvale, CA, United States of America

Igor Furlan