Topic
Pulse-frequency modulation
About: Pulse-frequency modulation is a research topic. Over the lifetime, 4151 publications have been published within this topic receiving 53039 citations. The topic is also known as: PFM.
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Patent•
11 Dec 2003TL;DR: In this article, a pulse width modulation voltage regulator is proposed to reduce a pulse modulation frequency of the PWR when a load current increases and to increase the pulse amplitude modulation frequency when the load current decreases.
Abstract: A pulse width modulation voltage regulator comprises a pulse width modulation circuit and a control circuit (103). The control circuit is operable to reduce a pulse modulation frequency of the pulse width modulation circuit when a load current increases and to increase the pulse modulation frequency of the pulse width modulation circuit when the load current decreases.
19 citations
Patent•
14 Sep 2009
TL;DR: A charge-and-add DC-DC voltage converter as discussed by the authors uses a switch network to switch between two states, either simultaneously charging a flying capacitor (one or any number) or creating a DC voltage on the output capacitor by connecting all flaying capacitors in series thus adding the input voltage to remaining voltages on flying capacitors after they were charged.
Abstract: A charge-and-add DC-DC voltage converter design using a switch network that toggles between two states, either simultaneously charging a flying capacitor (one or any number) or creating a DC voltage on the output capacitor by connecting all flaying capacitors in series thus adding the input voltage to remaining voltages on flying capacitors after they were charged. A pulse generator delivers a train of pulses to toggle the switch network. Depending on the applications, the train of pulses can be continuous when a fixed unregulated voltage must be delivered, or a defined number of pulses when voltage (power) surge is to be produced. The charge-and-add converters should be capable of delivering a regulated output voltage, and in this case, pulse-width modulation (PWM) or pulse frequency modulation (PFM) can be used.
19 citations
Patent•
22 Jul 2008TL;DR: In this paper, a method for modulating buck and boost modulation ramps of a multiple switch node power converter without overlap is proposed. But the method requires the power converter to reach its optimal operating point without overlap and eliminates any sub-harmonic switching.
Abstract: A method of and system for modulating buck and boost modulation ramps of a multiple switch node power converter without overlap. As the pulse width or duty cycle of the signal to a modulated complementary switching pair approaches a pre-established reference pulse width or duty cycle, plural fixed-width or fixed duty cycle pulses are generated and introduced to a nonmodulated complementary switching pair. A controller detects proximity to the pulse width or duty cycle limit and, correspondingly, initiates prematurely a pseudo-buck-boost mode in the power converter by generating fixed-width or fixed duty cycle pulses to the nonmodulated complementary switching pair while the duty cycles or pulse widths to the modulated complementary switching pair are still controlled by the appropriate modulation ramp. The net effect is that the power converter reaches its optimal operating point without overlap and eliminates any sub-harmonic switching.
19 citations
Patent•
25 Jan 2016
TL;DR: In this article, a distributed pulse-width modulation system includes an array of pulsewidth modulation elements, each element including a digital memory for storing a multi-bit digital value and a drive circuit that drives an output device in response to the digital value stored in the digital memory.
Abstract: A distributed pulse-width modulation system includes an array of pulse-width modulation elements, each element including a digital memory for storing a multi-bit digital value and a drive circuit that drives an output device in response to the multi-bit digital value stored in the digital memory. A system controller includes a memory for storing a multi-bit digital value for each element and a communication circuit for communicating each multi-bit digital value to each corresponding pulse-width modulation element.
19 citations
TL;DR: In this experiment, it is established that amplitude modulation was not taken into consideration by the birds in the experiment, even if other parameters were altered.
Abstract: The decoding process of distress calls uses many parameters. In our experiment we establish that amplitude modulation was not taken into consideration by the birds in the experiment, even if other parameters were altered. The decoding process that discards amplitude modulation appears well adapted to transmission at long range because amplitude modulation is always subject to degradation.
19 citations