Abstract:
A pulse width modulation system for use in a switching power supply circuit provides high-resolution pulse width modulated signals. The pulse width modulation system is configured to receive a control signal comprising a (m+n)-bit binary word and to provide a pulse width modulated signal with a predetermined average duty cycle having a resolution of substantially 2−(m+n). The pulse width modulation system includes a timing circuit for providing 2m timing signals, a dithering circuit, and a signal generator. Upon receiving the control signal, the dithering circuit is configured to provide a modified control signal, which comprises a series of up to 2n-bit binary words. The signal generator is configured to receive the timing signals and the modified control signal and to provide the pulse width modulated signal having a duty cycle, which, when averaged over 2n timing cycles, is approximately equal to the predetermined average duty cycle. The pulse width modulated signal is used by a switching power supply circuit to control at least one power switching device.
Abstract:
A system and method is provided for determining a voltage output of a programmable power converter based on programming voltage data received from one of a variety of alternate sources. Specifically, in one embodiment of the present invention, a control unit is adapted to monitor a digital data serial interface, a digital data parallel interface, and an analog data interface to determine whether programming voltage data has been received. If programming voltage data has been received, the data is used to determine an output voltage for the programmable power converter. If more than one set of programming voltage data has been received, a determination is made as to which set of data takes priority. The selected set of data is then used to determine an output voltage for the programmable power converter.
Abstract:
A pulse width modulation system for use in a switching power supply circuit provides high-resolution pulse width modulated signals. The pulse width modulation system is configured to receive a control signal comprising a (m+n)-bit binary word and to provide a pulse width modulated signal with a predetermined average duty cycle having a resolution of substantially 2−(m+n). The pulse width modulation system includes a timing circuit for providing 2m timing signals, a dithering circuit, and a signal generator. Upon receiving the control signal, the dithering circuit is configured to provide a modified control signal, which comprises a series of up to 2n m-bit binary words. The signal generator is configured to receive the timing signals and the modified control signal and to provide the pulse width modulated signal having a duty cycle, which, when averaged over 2n timing cycles, is approximately equal to the predetermined average duty cycle. The pulse width modulated signal is used by a switching power supply circuit to control at least one power switching device.
Abstract:
A pulse width modulation system for use in a switching power supply circuit provides high-resolution pulse width modulated signals. The pulse width modulation system is configured to receive a control signal comprising a (m+n)-bit binary word and to provide a pulse width modulated signal with a predetermined average duty cycle having a resolution of substantially 2−(m+n). The pulse width modulation system includes a timing circuit for providing 2m timing signals, a dithering circuit, and a signal generator. Upon receiving the control signal, the dithering circuit is configured to provide a modified control signal, which comprises a series of up to 2n m-bit binary words. The signal generator is configured to receive the timing signals and the modified control signal and to provide the pulse width modulated signal having a duty cycle, which, when averaged over 2n timing cycles, is approximately equal to the predetermined average duty cycle. The pulse width modulated signal is used by a switching power supply circuit to control at least one power switching device.
Abstract:
A system and method is provided for using a serial bus to communicate (either passively or actively) with a point-of-load (“POL”) regulator. Specifically, a power supply controller (“controller”) communicates with at least one POL regulators by writing and/or reading data (either synchronously or asynchronous) over a unidirectional or bi-directional serial bus. In one embodiment of the present invention, the controller is adapted to write initial-configuration data (e.g., output voltage set-point, current limit set-point, etc.) to at least one POL regulator via the serial bus. At least a portion of the initial-configuration data is then used by the POL regulator to produce a particular output. In another embodiment of the invention, each POL regulator includes at least one register for maintaining POL information, such as unique identification information, fault protection information, output voltage set-point data, current limit set-point data, etc. The controller is then adapted to monitor and retrieve this information (i.e., fault-monitoring data) via the serial bus while the POL regulators are operating.
Abstract:
A power supply comprises at least one power switch adapted to convey power between input and output terminals of the power supply, and a digital controller adapted to control operation of the at least one power switch responsive to an output measurement of the power supply. The digital controller comprises an analog-to-digital converter providing a digital error signal representing a difference between the output measurement and a reference value, a digital filter providing a digital control output based on a sum of previous error signals and previous control outputs, an error controller adapted to modify operation of the digital filter upon an error condition, and a digital pulse width modulator providing a control signal to the power switch having a pulse width corresponding to the digital control output. A method for controlling the power supply comprises the steps of receiving an output measurement of the power supply, sampling the output measurement to provide a digital error signal representing a difference between the output measurement and a reference value, filtering the digital error signal to provide a digital control output based on a sum of previous error signals and previous control outputs, modifying operation of the filtering step upon an error condition, and providing a control signal to the at least one power switch, the control signal having a pulse width corresponding to the digital control output.
Abstract:
A power control system comprises a plurality of power control groups, with each group comprising a plurality of individual point-of-load regulators each adapted to provide respective regulated voltage outputs. The point-of-load regulators may be selected for inclusion in a power control groups based on characteristics of loads supplied by the point-of-load regulators. An intermediate bus controller is coupled to each of said power control groups through a serial data bus interface common to each group and an OK status line for each respective group. A front end regulator provides an intermediate bus voltage to each of the plurality of power control groups and to the intermediate bus controller. The plurality of point-of-load regulators of each group each further comprises a respective fault manager adapted to detect fault conditions and selectively communicate notifications of the fault conditions to other ones of the plurality of point-of-load regulators of the group and to the intermediate bus controller. This way, a common response to the fault conditions is taken by the point-of-load regulators of the group and other groups. A method for managing faults in the power control system is also disclosed.
Abstract:
A switched mode power supply comprises a first switch coupled to an input power source, a second switch coupled to ground, and an output filter coupled to a phase node defined between the first and second switches. The first and second switches are responsive to a pulse width modulated signal to thereby regulate power provided to the output filter. A controller is provided in a feedback loop that monitors operation of the first and second switches and delays activation of one of the first and second switches to preclude simultaneous conduction. The controller comprises at least one delay control circuit adapted to delay delivery of the pulse width modulated signal to at least one of the first and second switches. The delay control circuit detects a phase difference between state transitions of the first and second switches and provides a delay corresponding to a magnitude of the phase difference.
Abstract:
The invention relates to a process and a device for determining the position P0 of an event with respect to a set of N photodetectors, inducing a signal in the N photodetectors. This process comprises the following steps: a) digitize the signal output by each photodetector; calculate the energy of the signal output by each photodetector, b) calculate the contribution of the column to the total energy, to the X value of the center of gravity of the event and to the Y value of the center of gravity of the event, for each column, c) determine the total energy induced by the event and the coordinates of the center of gravity of the event with respect to the N photodetectors.
Abstract:
Method and apparatus for determining a position of an event. The system processes signals from an assembly of N photodetectors and includes a signal generator for producing a signal representing the value of the maximum, or the energy, of a pulse delivered by the photodetector and is digitized. It also includes a signal generator for producing a threshold-exceeded signal for each photodetector when the amplitude of the signal representing the value of the maximum, or the energy, of the digitized pulse is greater than the threshold. It also includes a signal generator common to the photodetectors, for delivering a signal representing a position of an event as a function of the threshold-exceed signals. This device can be used with gamma cameras.