Patent us20080159378 – apparatus and method for generating multi-phase pulse width modulation (pwm … – google patentsuche
A pulse width modulation (PWM) generator featuring very high speed and high resolution capability and the ability to generate standard complementary PWM, push-pull PWM, variable offset PWM, multiphase PWM, current limit PWM, current reset PWM, and independent time base PWM while further providing automatic triggering for an analog-to-digital conversion (ADC) module that is precisely timed relative to the PWM signals. Pulse width modulation circuit for dc motor control Applications include control of a switching power supply that requires very high speed operation to obtain high resolution at high switching frequencies, and the ability to vary the phase relationships among the PWM output signals driving the power supply power components. Pulse width modulation arduino A single PWM duty cycle register may be used for updating any and/or all PWM generators at once to reduce the workload of a digital processor as compared to updating multiple duty cycle registers.
In existing analog PWM generation devices, the phase relationship among the PWM output signals is fixed by design.
Pulse width modulation in microcontroller Vendors produce devices for two, three or four phase outputs where the phase relationship among the outputs is evenly spread throughout the PWM cycle. Pulse width modulation theory A digital PWM module 1304 with a capability to offset the phase of the PWM signals is implemented in the Motorola MC68HC08SR12 and MC68HC908SR12 devices, but these devices can not vary the phase relations among the PWM outputs while the PWM generator is operational. 555 timer pulse width modulation U.S. Pulse width modulation inverter ppt Pat. What is meant by pulse width modulation No. Pulse width modulation controller kit 6,525,501, issued Feb. Pulse width modulation nedir 25, 2003, describes a method for implementing multiple simultaneous duty cycle register updates.
According to specific exemplary embodiments, dynamically updateable phase offset PWM generation may be implemented as follows, for example, in one of two ways: (1) The PWM generation module may use a digital adder module to add an offset to the PWM period counter. Pulse width modulation wiki This counter and adder combination provides the time base for the offset PWM signal generation. Pulse width modulation example An adder module is used that has an unique mechanism to handle the “roll-over” situation without requiring extra comparator logic. 555 pulse width modulation circuit (2) The PWM generation module may use multiple counter modules to create offset PWM signals, the offset PWM signals are generated by initializing each of the multiple PWM counters to values specified by the user. Pulse width modulation ac motor speed control A module provides synchronization of the counter modules among the PWM generators.
The present invention may be susceptible to various modifications and alternative forms. Pulse width modulation pic Specific embodiments of the present invention are illustrated by way of example in the drawings and are described herein in detail. Pulse width modulation disadvantages It should be understood, however, that the description set forth herein of specific embodiments is not intended to limit the present invention to the particular forms disclosed. Pulse width modulation generator Rather, all modifications, alternatives, and equivalents falling within the spirit and scope of the invention as defined by the appended claims are intended to be covered.
Referring to FIG. Pulse width modulation using 555 timer circuit diagram 13, depicted is a digital processor with a pulse width modulation module having dynamically adjustable phase offset capability, high speed operation and simultaneous update of multiple pulse width modulation duty cycle registers. Pulse width modulation for power converters principles and practice pdf The digital processor 1302 may be, for example but not limited to, a microprocessor, a microcontroller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic array (PLA), and the like. Pulse width modulation vfd The pulse width modulation (PWM) module 1304 may be coupled to the digital processor 1302 and may be packaged in the same integrated circuit package as is the digital processor 1302. Definition of pulse width modulation The digital processor 1302 and PWM module 1304 may be fabricated on the same integrated circuit die (not shown) or may be fabricated on different integrated circuit dice and packaged together in one integrated circuit package, or they may be packaged in separate integrated circuit packages.
For example, if the least significant two bits of the offset value are greater than the least significant two bits of the duty cycle value, then the most significant 14 bits of the offset value are incremented prior to being loaded into the main 14 bit timer/counter. Pulse width modulation fan At this point, the two bit counter 602 and the 14 bit counter 604 are totally “decoupled” and may not count in a strictly binary sequence. Pulse width modulation animation For example, depending on initial values, the count sequence for the least significant 4 bits of the total counter ( 604 and 602) could be: 0110 0111 0100 0101 1010 1011 1000 1001 1110 1111 1100 1101 instead of the traditional binary sequence 0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011. Pulse width modulation tutorial This “decoupling” of the lower two bits versus the upper 14 bits requires a special mechanism for implementing the duty cycle versus timer/counter comparator module. Pulse width modulation basics The upper 14 bits of a comparator is implemented as a standard binary “Less Than or Equal” comparator module. Pulse width modulation radiator fan controller The lower two bits of the comparator check for equality between the two bit counter and the lower two bits of the duty cycle value. Pulse width modulation experiment Because the lower two bit counter counts in a disconnected fashion from the upper 14 bit counter, a mechanism is required to hold the PWM output asserted (driven high) during the period of time when the upper 14 bits of the duty cycle equal the counter value and the lower 2 bit comparator has not yet detected an equality situation.
A digital PWM module 1304, such as is illustrated in FIG. Pulse width modulation matlab 11, may be used to drive the fine adjust module 702. Pulse width modulation led driver The fine adjust module 702 includes all of the circuitry required to add improved duty cycle resolution, improved phase offset resolution, and improved dead time resolution to the PWM signals outputted by a traditional digital PWM generator module ( FIG. Pulse width modulation dc motor 11). Advantages of sinusoidal pulse width modulation All standard digital PWM generator modules use counters and/or adder modules to increment a count value every clock period. Pulse width modulation duty cycle Digital counter modules are difficult to design to operate at high frequencies because the count process uses an “adder” module, either implicit in the counter module, or explicitly implemented to create a counter. Pulse width modulation using 555 Adder modules need to propagate a “carry” signal from the least significant bit of the adder output to the most significant bit of the adder output. Pulse width modulation synth This carry propagation process requires the carry signal to pass through many levels of logic, thus slowing the process of counting. Pulse width modulator hho According to the present invention, implementation of very small shift registers and small multiplexer modules allows operation at high speeds and thus high frequencies.
Referring to FIG. Pulse width modulation and demodulation 10, depicted is a schematic block diagram of a triggering circuit for an analog-to-digital converter (ADC). Uses of pulse width modulation Typically, the ADC is triggered so as to measure the voltage and currents in the power supply application module at a point in time when the inductor current is at its maximum. Pulse width modulation valve Typically, these measurements will be taken just before or after either the rising or falling edge of the PWM signal. Pulse width modulation vape This module adds or subtracts a user specified trigger offset value to/from the duty cycle register value if the user has selected that the trigger occur on the falling edge of the PWM signal. Sinusoidal pulse width modulation for 3 phase inverter If the user wants the trigger to occur on the rising edge of the PWM signal, either the trigger offset will be subtracted from the PWM period value, or added to 0000 to obtain the point in time just before the end of the PWM cycle, or just after the start of a new PWM cycle. Application of pulse width modulation If the PWM generator is in a mode where the PWM signal is modified by an external signal, then the offsets are positive relative to the external PWM control signal.
The present invention has been described in terms of specific exemplary embodiments. Pulse width modulation microcontroller In accordance with the present invention, the parameters for a system may be varied, typically with a design engineer specifying and selecting them for the desired application. Sine pulse width modulation Further, it is contemplated that other embodiments, which may be devised readily by persons of ordinary skill in the art based on the teachings set forth herein, may be within the scope of the invention, which is defined by the appended claims. Disadvantages of pulse width modulation The present invention may be modified and practiced in different but equivalent manners that will be apparent to those skilled in the art and having the benefit of the teachings set forth herein.