Abstract:
Methods and systems are disclosed for predictive feedback compensation (PFC) circuitry for suppressing distortions caused by supply voltage variations and output amplitude switching non-idealities in pulse width modulated (PWM) switching amplifiers by pre-compensating the PWM input based upon the supply voltage or output pulse amplitude. Output amplitude errors associated with previous PWM output signals are used to predict output amplitude errors expected for future PWM output signals. These predicted output amplitude errors are then used to adjust the pulse widths for the future PWM output signals. Closed loop width adjustment can also be applied by providing timing feedback signals associated with the pre-compensation of the PWM input signals. Traditional feedback techniques can also be used in conjunction with the predictive feedback compensation (PFC) circuitry.
Abstract:
A technique includes providing a plurality of local oscillator signals such that each of the local oscillator signals has a different phase. The technique includes providing scaling units to scale the input signal pursuant to different scaling factors to generate scaled input signals. The scaling factors are selected on a periodic function of the phases. The technique also includes providing mixing circuits to mix the local oscillator signals with the scaled input signals to generate mixed signals and providing an adder to combine the mixed signals to generate an output signal.
Abstract:
A system for analyzing the operation of a switching power converter includes a digital controller for receiving an analog signal representing the output DC voltage of the power converter for comparison to a desired output voltage level and generating switching control signals to control the operation of the power supply to regulate the output DC voltage to said output voltage level. At least one portion of a control loop within the digital controller may he switched into the control loop in a first mode of operation and out of the control loop in a second mode of operation. A microcontroller emulates the operation of the at least one portion of the control loop during the second mode of operation.
Abstract:
A microcontroller unit (MCU) is disclosed with a stand-alone Real Time Clock (RTC). The MCU includes a processing circuit for receiving digital information and processing said received digital information. A primary clock circuit provides the timing for the processing circuit. A power control circuit controls the power to the processing circuit and the primary clock circuit to control the operation thereof to operate in at least a full power mode drawing a full power level from a supply voltage input and a reduced power mode drawing less than the full power level from the supply voltage input. A stand-alone RTC circuit is also provided, the standalone RTC circuit including an RTC clock circuit operating independent of the primary clock circuit. A timer clocked by the RTC clock circuit is operable to increment a stored time value for output therefrom, the RTC clock circuit having a defined time base. An input/output (I/O) device provides access by the processing circuit to the results output by the timer. A power management circuitry manages the power to the stand-alone RTC circuit, such that the RTC clock circuit, the timer, and the I/O device operate regardless of the power mode of operation of the processing circuitry and the primary clock circuit.
Abstract:
A digital controller (408, 412, 416) for controlling the operation of a DC-DC switching converter is disclosed. A digital feedback control system is provided for receiving an analog input voltage (406) representing the output of the switching converter and digitally processing the analog input voltage by comparing it to a reference voltage and then determining analog drive signals to control the operation of the switching converter (402) to provide a regulated output. The digital feedback control system (408, 412, 416) operates in accordance with predetermined operating parametrics. The digital feedback control system (408, 412, 416) also has monitoring inputs and control inputs. A microcontroller (442) monitors the operation of the digital feedback control system and is able to change the operating parametrics under certain predetermined conditions.
Abstract:
A method and apparatus provide techniques for electrically isolating switching devices MI (M l), M2 (M2) in a stacked RF power amplifier, which prevents the switching devices MI (M1), M2 (M2) from being subjected to high breakdown voltages. The isolation provided allows the power amplifier to be implemented on an integrated circuit (Fig. 5).
Abstract:
Radio-frequency (RF) apparatus includes receiver analog circuitry that receives an RF signal and provides at least one digital signal to receiver digital circuitry that functions in cooperation with the receiver analog circuitry. The interface between the receiver analog circuitry and the receiver digital circuitry includes configurable signal lines that function as a serial interface, or as a data and clock signal interface, depending on the state of a control signal.
Abstract:
In a feedback system such as a PLL, the integrating function associated with a loop filter capacitor is instead implemented digitally and is easily implemented on the same integrated circuit die as the PLL. In a preferred embodiment, an analog phase detector is utilized whose phase error output signal is delta-sigma modulated to encode the magnitude of the phase error using a digital (i.e., discrete-time and discrete-value) signal. This digital phase error signal is "integrated" by a digital integration block including, for example, a digital accumulator, whose output is then converted to an analog signal, optionally combined with a loop feed-forward signal, and then conveyed as a control voltage to the voltage-controlled oscillator. The equivalent "size" of the integrating capacitor function provided by the digital integration block may be varied by increasing or decreasing the bit resolution of circuits within the digital block.
Abstract:
In one embodiment, the present invention provide a method for detecting signal quality metrics of a constant modulo (CM) signal received in two different signal paths, and combining the signal from the two signal paths based at least in part on the detected first and second signal quality metrics. Such method may be implemented in a radio receiver such as an automobile receiver.
Abstract:
A demodulator can include first data and clock pads to couple the demodulator to a host device via a first bus, and second data and clock pads to couple the demodulator to a radio frequency (RF) tuner via a second bus. The device may further include passthrough logic to couple host data and a host clock from the first bus to the second bus and to couple tuner data from the second bus to the first bus during a passthrough mode. During this mode, however, the two buses may remain electrically decoupled. When the passthrough mode is disabled, the RF tuner is thus shielded from noise present on the first bus.