Abstract:
Radio Frequency (RF) signal conditioning circuitry, which includes RF detection circuitry and RF attenuation circuitry is disclosed. The RF detection circuitry receives and detects an RF sample signal to provide an RF detection signal. The RF attenuation circuitry has an attenuation circuitry input, and receives and attenuates the RF sample signal via the attenuation circuitry input to provide an attenuated RF signal. The RF attenuation circuitry presents an attenuation circuitry input impedance at the attenuation circuitry input. The attenuated RF signal and the RF detection signal are provided concurrently.
Abstract:
A sample-and-hold (SAH) current estimating circuit and a first switching power supply are disclosed. The first switching power supply provides a first switching power supply output signal based on a series switching element and a setpoint. The SAH current estimating circuit samples a voltage across the series switching element of the first switching power supply during an ON state of the series switching element and during a ramping signal peak to provide an SAH output signal based on an estimate of an output current of the first switching power supply output signal. The first switching power supply selects the ON state of the series switching element, such that during the ramping signal peak, the series switching element has a series current having a magnitude, which is about equal to a magnitude of the output current of the first switching power supply output signal.
Abstract:
An electromechanical circuit uses a plunger to open and close a circuit as an indication of the position of a flip portion of a mobile communication device. The plunger includes an electrically conductive portion which slidingly contacts a contact pad. Upon contacting the contact pad, a change in logic states occurs which triggers circuitry to activate or de-activate the internal electronics within the communication device. This allows a user, for example, to activate a phone to receive a call without having to depress a specified switch. A common cam-follower mechanical configuration is used to cause the plunger to translate axially as the flip portion is moved.
Abstract:
Radio frequency (RF) power amplifier (PA) circuitry, which transmits RF signals is disclosed. The RF PA circuitry includes a final stage, a final stage current digital-to-analog converter (IDAC), and a final stage temperature compensation circuit. A final stage current reference circuit may provide an uncompensated final stage reference current to the final stage temperature compensation circuit, which receives and temperature compensates the uncompensated final stage reference current to provide a final stage reference current. The final stage IDAC uses the final stage reference current in a digital-to-analog conversion to provide a final stage bias signal to bias the final stage. The temperature compensation provided by the final stage temperature compensation circuit is selectable.
Abstract:
A charge pump of a PA bias power supply, PA bias circuitry, and a process to optimize efficiency of the PA bias power supply are disclosed. The charge pump operates in one of multiple bias supply pump operating modes, which include at least a bias supply pump-up operating mode and a bias supply bypass operating mode. The process prevents selection of the bias supply bypass operating mode unless a DC power supply voltage is adequate to allow the PA bias circuitry to provide minimum output regulation voltage at a specified current. Otherwise, the bias supply pump-up operating mode is selected. The charge pump operates more efficiently in the bias supply bypass operating mode than in the bias supply pump-up operating mode; therefore, selection of the bias supply bypass operating mode, when possible, increases efficiency.
Abstract:
A sample-and-hold (SAH) current estimating circuit and a first switching power supply are disclosed. The first switching power supply provides a first switching power supply output signal based on a series switching element and a setpoint. The SAH current estimating circuit samples a voltage across the series switching element of the first switching power supply during an ON state of the series switching element and during a ramping signal peak to provide an SAH output signal based on an estimate of an output current of the first switching power supply output signal. The first switching power supply selects the ON state of the series switching element, such that during the ramping signal peak, the series switching element has a series current having a magnitude, which is about equal to a magnitude of the output current of the first switching power supply output signal.
Abstract:
A power amplifier (PA) envelope power supply, which provides an envelope power supply signal to radio frequency (RF) PA circuitry, and a process to prevent undershoot of the PA envelope power supply is disclosed. The process includes determining if an envelope control signal to the PA envelope power supply has a step change from a high magnitude to a low magnitude that exceeds a step change limit. Such a step change may cause undershoot of the PA envelope power supply. As such, if the step change exceeds the step change limit, the envelope control signal is modified to use an intermediate magnitude for period of time. Otherwise, if the step change does not exceed the step change limit, the envelope control signal is not modified.
Abstract:
Embodiments of the present disclosure relate to an overlay class F choke of a radio frequency (RF) power amplifier (PA) stage and an RF PA amplifying transistor of the RF PA stage. The overlay class F choke includes a pair of mutually coupled class F inductive elements, which are coupled in series between a PA envelope power supply and a collector of the RF PA amplifying transistor. In one embodiment of the RF PA stage, the RF PA stage receives and amplifies an RF stage input signal to provide an RF stage output signal using the RF PA amplifying transistor. The collector of the RF PA amplifying transistor provides the RF stage output signal. The PA envelope power supply provides an envelope power supply signal to the overlay class F choke. The envelope power supply signal provides power for amplification.
Abstract:
A configurable 2-wire/3-wire serial communications interface (C23SCI), which includes start-of-sequence (SOS) detection circuitry and sequence processing circuitry, is disclosed. When the SOS detection circuitry is coupled to a 2-wire serial communications bus, the SOS detection circuitry detects an SOS of a received sequence based on a serial data signal and a serial clock signal. When the SOS detection circuitry is coupled to a 3-wire serial communications bus, the SOS detection circuitry detects the SOS of the received sequence based on a chip select (CS) signal. In response to detecting the SOS, the SOS detection circuitry provides an SOS detection signal to the sequence processing circuitry, which initiates processing of the received sequence using the serial data signal and the serial clock signal. The received sequence is associated with one of multiple serial communications protocols.
Abstract:
Radio frequency (RF) power amplifier (PA) circuitry, which transmits RF signals is disclosed. The RF PA circuitry includes a final stage, a final stage current digital-to-analog converter (IDAC), and a final stage temperature compensation circuit. A final stage current reference circuit may provide an uncompensated final stage reference current to the final stage temperature compensation circuit, which receives and temperature compensates the uncompensated final stage reference current to provide a final stage reference current. The final stage IDAC uses the final stage reference current in a digital-to-analog conversion to provide a final stage bias signal to bias the final stage. The temperature compensation provided by the final stage temperature compensation circuit is selectable.