Abstract: In order to extend the measurement range of a current sensor, a current divider is formed by a first conductor formed in a current sensor that is mounted on a printed circuit board and a second conductor on the printed circuit board that electrically shorts at least one input terminal of the current sensor to at least one output terminal of the current sensor. The input terminal of the current sensor supplies the current to be measured to the first conductor and the output terminal supplies the measured current back to the printed circuit board.

Abstract: A method and apparatus is provided for use with a power amplifier to provide a regulated supply to the power amplifier. The invention uses a combination of voltage and current regulation to overcome the problems encountered in the prior art. In one example, voltage regulation is used at high power levels, while current regulation is used at low power levels.

Abstract: In a power amplifier, a serial bus interface is provided for sending and receiving information to other devices, such as a baseband controller. The power amplifier includes several control pins that can be used as a serial interface, or alternately, with a direct pin control interface. The power amplifier uses various techniques to address noise problems related to the use of a serial bus with a power amplifier.

Abstract: A digital direct access arrangement (DAA) circuitry may be used to terminate the telephone connections at the user's end that provides a communication path for signals to and from the phone lines. Briefly described, the DAA provides a programmable circuit for the DC termination for a variety of international phone standards. The invention may also be utilized with circuitry for transmitting and receiving a signal across a capacitive isolation barrier. More particularly, a DC holding circuit is provided in which a programmable DC current limiting mode is available. In the current limiting mode, power may be dissipated in devices external to a DAA integrated circuit. Moreover, much of the power may be dissipated in external passive devices, such as resistors.

Abstract: A method and apparatus provides techniques for electrically isolating switching devices in a stacked RF power amplifier, which prevents the switching devices from being subjected to high breakdown voltages. The isolation provided allows the power amplifier to be implemented on an integrated circuit.

Abstract: In a power amplifier, a serial bus interface is provided for sending and receiving information to other devices, such as a baseband controller. The power amplifier includes several control pins that can be used as a serial interface, or alternately, with a direct pin control interface. The serial bus interface can be used with digital power control techniques that provide various advantages over conventional power amplifiers.

Abstract: A current sensor includes a coils located within the integrated circuit die and inductively coupled to a conductor located in the integrated circuit package holding the die. The inductors sense the current in the conductor and supply the sensed signal to an integrator that supplies a voltage indicative of the current in the conductor.

Abstract: An apparatus includes a regulator circuit that generates a voltage in response to an input current being supplied to an input terminal and functional circuitry, powered by the voltage generated by the regulator circuit. The functional circuitry, e.g., an oscillator, generates a signal using the generated voltage, the signal indicative that the current is being supplied to the apparatus. The signal can be provided over an isolation link to provide a control signal for controlling a high voltage driver circuit.

Abstract: A method and apparatus are provided for use with a power amplifier for protecting active devices on the power amplifier. A peak detector is used by control circuitry to detect the presence of a peak voltage that exceeds a threshold voltage. In response to the detection of a peak voltage, the gain of the power amplifier is reduced.

Abstract: A method and apparatus is provided for dynamically changing the biasing conditions of a voltage regulator to overcome the problems caused by various conditions. The invention includes a detector and a bias control circuit for applying bias current to the voltage regulator to compensate for a detected condition.

Abstract: A method and apparatus if provided for shielding a capacitor structure formed in a semiconductor device. In a capacitor formed in an integrated circuit, one or more shields are disposed around layers of conductive strips to shield the capacitor. The shields confine the electric fields between the limits of the shields.

Abstract: A method and apparatus provides an input structure for a power amplifier. In one example, the input structure has an input network and a predriver circuit to provide an input signal to the power amplifier. The input network includes a transformer for helping to maintain a constant input impedance. The predriver includes a limiting amplifier that provides isolation between the power amplifier and the RF input. A DC feedback circuit is used by the predriver that maintains the DC level of the inverters to a desired level.

Abstract: A current sensor includes an integrator for providing an output signal, responsive to a detected current, and a reset circuit. The reset circuit, responsive to a control signal, resets the integrator for a time period shorter than an assertion time of the supplied control signal.

Abstract: A current sensor includes a sensing circuit for sensing current and supplying indications thereof. The current sensor also includes two or more output terminals coupled to the sensing circuit that alternately supply respective indications of the sensed current according to control signals supplied to the current sensor.

Abstract: A method and apparatus provides an input structure for a power amplifier. In one example, the input structure has an input network and a predriver circuit to provide an input signal to the power amplifier. The input network includes a transformer for helping to maintain a constant input impedance. The predriver includes a limiting amplifier that provides isolation between the power amplifier and the RF input. A DC feedback circuit is used by the predriver that maintains the DC level of the inverters to a desired level.

Abstract: A current sensor includes coupled inductors that generate an output current responsive to a detected current. The coupled inductor is implemented in an integrated circuit. An integrator circuit generates a sensed voltage responsive to the output current.

Abstract: A digital direct access arrangement (DAA) circuitry may be used to terminate the telephone connections at the user's end that provides a communication path for signals to and from the phone lines. Briefly described, the DAA provides a programmable means for the DC termination for a variety of international phone standards. The invention may also be utilized with means for transmitting and receiving a signal across a capacitive isolation barrier. More particularly, a DC holding circuit is provided in which a programmable DC current limiting mode is available. In the current limiting mode, power may be dissipated in devices external to a DAA integrated circuit. Moreover, much of the power may be dissipated in external passive devices, such as resistors.

Abstract: A method and apparatus are provided for use with a power amplifier for protecting active devices on the power amplifier. A peak detector is used by control circuitry to detect the presence of a peak voltage that exceeds a threshold voltage. In response to the detection of a peak voltage, the gain of the power amplifier is reduced.

Abstract: A surge clamp circuit that may be implemented with DAA circuitry to limit the total voltage developed across one or more line side capacitors due to charge pumping phenomenon during a multi-transient events such as lightning strikes. The surge clamp circuit is capable of electronically sensing a transient event (e.g., lightning strike) and of momentarily turning on one or more components of a DAA hookswitch circuit during on hook mode to discharge the voltage developed across one or more line side capacitors before it reaches critical breakdown levels. The surge clamp circuit may be configured with a clamping sensitivity selected so that the DAA hookswitch circuitry is only activated or turned on upon occurrence of relatively large and potentially damaging transient events, and not upon occurrence of non-damaging transient events, such as operational signals.

Abstract: A current sensor includes an integrator for providing an output signal, responsive to a detected current, and a reset circuit. The reset circuit, responsive to a control signal, resets the integrator for a time period shorter than an assertion time of the supplied control signal.