CN214205485U

CN214205485U - PWM signal modulation device

Info

Publication number: CN214205485U
Application number: CN202023090863.2U
Authority: CN
Inventors: 陶伟; 辛昌隆; 纳伦达尔·韦努戈帕尔
Original assignee: Ningbo Longying Semiconductor Co ltd
Current assignee: Ningbo Longying Semiconductor Co ltd
Priority date: 2020-12-21
Filing date: 2020-12-21
Publication date: 2021-09-14
Anticipated expiration: 2030-12-21

Abstract

The utility model relates to a PWM signal modulation device, including consecutive first level conversion module, PWM signal modulation module, buffer module, second level conversion module and output module, still include signal acquisition processing module, signal acquisition processing module gathers the load variation situation and the secondary side feedback signal of primary signal respectively to carry out logical operation to the signal of gathering and handle, and right according to the processing result PWM signal modulation module controls. The utility model discloses can satisfy the demand of system to quick response.

Description

PWM signal modulation device

Technical Field

The utility model relates to a signal modulation technical field especially relates to a PWM signal modulation device.

Background

Electromagnetic interference (EMI for short) noise of the switching power supply comes from the switching device, and the mainstream EMI suppression technology slows down the driving speed of the switching device at the cost of sacrificing efficiency, and the modulation technology of the switching signal is already included in the low-power supply management chip. The prior patent publication CN101102108A discloses a method for phase modulation, which includes a phase-locked loop technique, where there is a certain time delay in actual phase modulation, i.e. there is a time delay in obtaining phase modulation for the input signal and the output signal.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a PWM signal modulation device is provided, can satisfy the demand of system to quick response.

The utility model provides a technical scheme that its technical problem adopted is: the PWM signal modulation device comprises a first level conversion module, a PWM signal modulation module, a buffer module, a second level conversion module and an output module which are sequentially connected, and further comprises a signal acquisition and processing module which is used for respectively acquiring the load change condition of a primary side signal and a secondary side feedback signal, carrying out logic operation processing on the acquired signals, and controlling the PWM signal modulation module according to the processing result.

The signal acquisition processing module comprises two input OR gates and a switching tube, wherein the first input end of each input OR gate is connected with a primary side signal, the second input end of each input OR gate is connected with a secondary side feedback signal, the output end of each input OR gate is connected with the gate pole of the switching tube, and the output end of the switching tube is connected with the enabling end of the PWM signal modulation module.

The PWM signal modulation module includes: a phase offset generator for applying a variable amount of phase offset to each modulation cycle of the input signal; a phase modulation read-only memory for storing a coefficient determined when a phase shift amount is applied at a specific time; a phase controller for outputting a modulated signal having a phase offset determined by the coefficient.

The output module is a totem-pole circuit.

Advantageous effects

Since the technical scheme is used, compared with the prior art, the utility model, have following advantage and positive effect: the utility model discloses an increase signal acquisition processing module, when the load takes place the sudden change, satisfy the high-speed response to the output load, close the modulation to the PWM signal, treat that the system gets into under the stable state, PWM signal modulation restart. The utility model discloses a phase modulation technique modulate the PWM signal to can remain the duty cycle of former signal in order to reduce the EMI transmission. The utility model discloses an output module adopts totem-pole circuit to realize, can directly be used for the drive of MOS pipe, and convenient to use is nimble.

Drawings

Fig. 1 is a block diagram of the structure of an embodiment of the present invention;

fig. 2 is a circuit diagram of a signal acquisition processing module in an embodiment of the present invention;

fig. 3 is a schematic diagram of a PWM signal modulation module according to an embodiment of the present invention;

fig. 4 is a circuit diagram of an output module according to an embodiment of the present invention.

Detailed Description

The present invention will be further described with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that various changes and modifications of the present invention may be made by those skilled in the art after reading the teachings of the present invention, and these equivalents also fall within the scope of the appended claims.

The utility model discloses an embodiment relates to a PWM signal modulation device, as shown in FIG. 1, including consecutive first level shift module, PWM signal modulation module, buffer module, second level shift module and output module. The first level conversion module is used for carrying out level conversion on an input PWM signal to form a modulatable signal. The PWM signal modulation module modulates signals by adopting a phase modulation technology, and because the phase modulation technology does not contain a phase-locked loop function, the duty ratio signals of the PWM signals are not affected, and the duty ratio of the original signals can be kept. The buffer module is used for temporarily storing the modulated signals so as to increase the anti-interference performance. And the second level conversion module is used for carrying out level conversion on the signals temporarily stored in the buffer module to form PWM signals. The output module is used for outputting the PWM signal to a load so as to effectively control the load.

The PWM signal modulation apparatus according to this embodiment further includes a signal acquisition processing module, which acquires a load change condition of the primary side signal and the secondary side feedback signal, performs logical operation processing on the acquired signals, and controls the PWM signal modulation module according to a processing result. As shown in fig. 2, the signal acquisition and processing module includes two input or gates and a switching tube, a first input end of the two input or gates is connected to the primary side signal, a second input end is connected to the secondary side feedback signal, an output end is connected to a gate electrode of the switching tube, and an output end of the switching tube is connected to an enable end of the PWM signal modulation module.

Therefore, the signal acquisition and processing module can meet the requirement of high-speed response to the output load when meeting the sudden change condition of the output load for acquiring the load change of the primary side signal and the secondary side feedback signal, the modulation of the PWM signal is closed, and the PWM signal modulation is restarted when the system enters a steady state. The transient response time is generally completed within mS level, so that when a strong load change signal is detected, the modulation function is immediately turned off, and the loop response time of the system can not be influenced.

As shown in fig. 3, the PWM signal modulation module according to the present embodiment includes: a phase offset generator for applying a variable amount of phase offset to each modulation cycle of the input signal; a phase modulation read-only memory for storing a coefficient determined when a phase shift amount is applied at a specific time; a phase controller for outputting a modulated signal having a phase offset determined by the coefficient. The output modulation signal has very small phase deviation, the phase modulation control can be realized, and the output modulation signal has a modulation ratio larger than 1.

As shown in fig. 4, the output module of the present embodiment is a totem-pole circuit. The totem pole circuit comprises a PNP triode and an NPN triode, wherein the base electrode of the NPN triode is connected with the output end of the second level conversion module, the collector electrode of the NPN triode is connected with a power supply, and the emitter electrode of the NPN triode is connected with the emitter electrode of the PNP triode; the base electrode of the PNP triode is also connected with the output end of the second level conversion module, the collector electrode of the PNP triode is grounded, and the emitter electrode of the PNP triode is connected with the emitter electrode of the NPN triode. The totem-pole circuit can be directly used for driving a MOS tube to be used as a switching device of a motor or a power supply.

It is not difficult to discover, the utility model discloses an increase signal acquisition processing module, when the load takes place the sudden change, satisfy the high-speed response to the output load, close the modulation to the PWM signal, treat that the system gets into under the stable state, PWM signal modulation restarts. The utility model discloses a phase modulation technique modulate the PWM signal to can remain the duty cycle of former signal in order to reduce the EMI transmission. The utility model discloses an output module adopts totem-pole circuit to realize, can directly be used for the drive of MOS pipe, and convenient to use is nimble.

Claims

1. A PWM signal modulation device comprises a first level conversion module, a PWM signal modulation module, a buffer module, a second level conversion module and an output module which are sequentially connected, and is characterized by further comprising a signal acquisition and processing module, wherein the signal acquisition and processing module is used for respectively acquiring the load change condition of a primary side signal and a secondary side feedback signal, performing logic operation processing on the acquired signals, and controlling the PWM signal modulation module according to the processing result.

2. The PWM signal modulation apparatus according to claim 1, wherein the signal acquisition processing module comprises two input or gates and a switching tube, a first input terminal of the two input or gates is connected to the primary side signal, a second input terminal of the two input or gates is connected to the secondary side feedback signal, an output terminal of the two input or gates is connected to a gate of the switching tube, and an output terminal of the switching tube is connected to the enable terminal of the PWM signal modulation module.

3. The PWM signal modulation apparatus according to claim 1, wherein the PWM signal modulation module comprises: a phase offset generator for applying a variable amount of phase offset to each modulation cycle of the input signal; a phase modulation read only memory for storing coefficients determined when a phase offset is applied; a phase controller for outputting a modulated signal having a phase offset determined by the coefficient.

4. The PWM signal modulation apparatus according to claim 1, wherein the output module is a totem-pole circuit.