CN218100031U

CN218100031U - Low-power-consumption constant current source output system

Info

Publication number: CN218100031U
Application number: CN202222404952.2U
Authority: CN
Inventors: 陈闯; 赵志强; 陈可可; 倪娟
Original assignee: Nanjing Keyuan Intelligent Technology Group Co ltd
Current assignee: Nanjing Keyuan Intelligent Technology Group Co ltd
Priority date: 2022-09-07
Filing date: 2022-09-07
Publication date: 2022-12-20
Anticipated expiration: 2032-09-07

Abstract

The utility model discloses a constant current source output system of low-power consumption, include: the voltage-adjustable power supply module is used for providing a constant current source driving power supply; the V/I conversion module is used for converting voltage/current to realize constant current source output; and the return detection module is used for acquiring the voltage of an external load in real time and feeding back an adjusting signal to the adjustable voltage power supply module. The utility model discloses a go back to examine the module and realize load voltage control, and then adjust the voltage-adjustable power module, but make the minimum voltage of voltage-adjustable power module output maintenance system steady operation, constant current source output system's power utilization ratio obtains improving, has effectively realized the reduction of system's consumption.

Description

Low-power-consumption constant current source output system

Technical Field

The utility model relates to a observe and control technical field, concretely relates to constant current source output system of low-power consumption.

Background

The 4-20mA DC (1-5V DC) signal system is an analog signal transmission standard adopted by the International Electrotechnical Commission (IEC) process control system. 4-20mA is often used in industrial applications, and the current signal is not easy to interfere.

A4-20 mA output circuit on a hardware circuit is designed by adopting a constant current source output circuit, and when the load is changed within an allowable range, the output current is constant. When the load R reaches the limit, the output voltage exceeds/approaches the internal power supply due to U = I × R, the circuit cannot achieve constant current output, i.e., the output current drops or turns off.

The U inside the conventional constant current source output system is fixed. And power consumption P = U × I, and the power consumption is unchanged after the output current is fixed. When the external load R is small, the internal voltage drop delta U is large, most of the total power consumption is converted into self-heating inside the product, and the problems of large internal temperature rise of the product, low power utilization rate and the like are caused.

The prior art generally adopts:

1. the ADC is used for collecting the return detection signal and dynamically adjusting the DCDC output through the MCU, the structure is complex, the cost is high, and the real-time performance and the dynamic response are poor.

2. Through the mode of differential acquisition plus reference, need to gather MOS pipe D utmost point and S utmost point voltage simultaneously, and provide the reference source, the circuit structure is relatively complicated.

Disclosure of Invention

The utility model aims at solving the defect that exists among the prior art, providing a constant current source output system of low-power consumption, this constant current source output system improves based on traditional constant current source current circuit, through introducing closed loop power regulation, has effectively reduced constant current source output system's consumption has solved the power utilization and has rateed lowly, the inside spontaneous heating serious problem of system.

In order to achieve the above object, the present invention provides a constant current source output system with low power consumption, including: the voltage-adjustable power supply module is used for providing a constant current source driving power supply; the V/I conversion module is used for converting voltage/current to realize constant current source output; and the return detection module is used for acquiring the voltage of an external load in real time and feeding back an adjusting signal to the adjustable voltage power supply module.

The utility model discloses a go back to examine the module and realize load voltage control, and then adjust the voltage-adjustable power module, but make the minimum voltage of voltage-adjustable power module output maintenance system steady operation, constant current source output system's power utilization ratio obtains improving, has effectively realized the reduction of system's consumption.

Furthermore, a first input end (power supply input end) of the voltage-adjustable power supply module is connected with an external power supply output end; a second input end (feedback end) of the adjustable voltage power supply module is connected with the output end of the return detection module; the output end of the adjustable voltage power supply module is connected with the input end of the V/I conversion module; the V/I conversion module adopts an MOS as a driving stage, a first output end of the V/I conversion module is connected with an input end of the return detection module, and a second output end of the V/I conversion module is connected with an input end of the external load; and the input end of the V/I conversion module is connected with the output of an external DAC (digital-to-analog converter) or the output of an analog circuit.

Further, the V/I conversion module can adopt two forms of outflow (Current Source) or inflow (Current Source).

Furthermore, the rechecking module comprises a following circuit and an inverse proportional circuit which are constructed by an operational amplifier, the input end of the following circuit is connected with an external load, the output end of the following circuit is connected with the input end of the inverse proportional circuit, and the output end of the inverse proportional circuit provides feedback adjustment voltage for the voltage-adjustable power supply module.

Further, the voltage-adjustable power supply module supports closed-loop feedback regulation, and the voltage architecture may be Boost, buck, flyback, forward, or a combination thereof.

Compared with the prior art, the utility model has the following advantages:

the utility model discloses a core is the return and examines the module design and with adjustable voltage power module's matching design, through the realization load voltage control of returning and examining the module, through the output voltage of the reversed phase proportion circuit dynamic adjustment adjustable voltage power module that single-ended fortune was put to constitute, but makes the minimum voltage of adjustable voltage power module output maintenance system steady operation, MOS pipe pressure drop VDS relatively fixed (VDS > VGS-VGS (th)) like this. The adjustable voltage power supply is designed in a mode of Boost, buck, flyback, forward and the like, so that the efficiency is high, the total power consumption of the system is determined by a single output current through the closed-loop adjustment, and the total power consumption is converted into a power consumption related to the output current and a load, so that the low-power-consumption design is effectively realized.

It should be understood that all combinations of the foregoing concepts and additional concepts described in greater detail below may be considered as part of the inventive subject matter of this disclosure provided such concepts are not mutually inconsistent.

The foregoing and other aspects, embodiments and features of the present teachings can be more fully understood from the following description in conjunction with the accompanying drawings. Additional aspects of the present invention, such as features and/or advantages of exemplary embodiments, will be apparent from the description which follows, or may be learned by practice of the specific embodiments in accordance with the teachings of the present invention.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a schematic block diagram of a low power consumption constant current source output system according to the present invention;

fig. 2 is a circuit topology diagram of the voltage-adjustable power module of the present invention;

FIG. 3 is a circuit topology diagram of the rechecking module of the present invention;

fig. 4 is a circuit topology diagram of the V/I conversion module of the present invention.

Detailed Description

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention will be combined below to clearly and completely describe the technical solution of the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be obtained by a person skilled in the art without any inventive work based on the described embodiments of the present invention, belong to the protection scope of the present invention. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.

The use of "first," "second," and similar terms in the description and in the claims does not indicate any order, quantity, or importance, but rather is used to distinguish one element from another. Similarly, the singular forms "a," "an," or "the" do not denote a limitation of quantity, but rather denote the presence of at least one, unless the context clearly dictates otherwise. The terms "comprises," "comprising," or the like, mean that the elements or items listed before "comprises" or "comprising" encompass the features, integers, steps, operations, elements, and/or components listed after "comprising" or "comprising," and do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute position of the object to be described is changed, the relative positional relationships may also be changed accordingly.

The utility model provides a constant current source output system of low-power consumption. The circuit is composed of an inverse proportional circuit composed of an operational amplifier, the voltage-adjustable power supply module is designed by adopting a voltage-adjustable DCDC chip, the voltage-adjustable power supply module and the voltage-adjustable DCDC chip are combined to realize real-time monitoring of load voltage, and the voltage-adjustable power supply module is dynamically adjusted by tracking the magnitude of the load voltage, so that the voltage-adjustable power supply module outputs the minimum voltage which can be reliably tracked by the V/I conversion module circuit. The voltage reduction reduces the system power consumption.

The present invention discloses a low power consumption constant current source output system, which is further described in detail with reference to the embodiments shown in the drawings.

As shown in fig. 1, a low-power constant current source output system generally comprises a voltage-adjustable power module, a V/I conversion module, and a feedback module, and is connected to an external load. The voltage-adjustable power supply module is used for generating a constant current source driving power supply, and the V/I conversion module is used for realizing voltage/current conversion and constant current source output. Because the output current of the load and the constant current source is not fixed, the load voltage is collected in real time through the return detection module and is used for adjusting the voltage-adjustable power supply module in real time, so that the MOS transistor V is formed _DS >V _GS -V _GS(th) Operating in the linear amplification region.

And the second input end of the adjustable voltage power supply module is connected with the output end of the return detection module, and the output end of the adjustable voltage power supply module is connected with the input end of the V/I conversion module.

In order to realize dynamic power supply adjustment, so that the power supply output is dynamically adjusted according to the output sizes of the load and the constant current source, the voltage-adjustable power supply module is designed as a voltage-stabilized power supply, as shown in fig. 2, and includes: the DC/DC chip and the resistance feedback network, wherein the feedback network is composed of resistors R4, R5 and R6. The power supply constructed by the figure 2 supports negative feedback regulation, and in order to improve the effect of closed loop regulation of the power supply, a resistor R6 is adopted to participate in voltage regulation of the DCDC module by Vadj voltage.

The specific implementation is as follows: when the voltage Vf of the load increases due to the increase of the current or the increase of the internal resistance, vadj decreases with the increase of Vf due to the adoption of the inverse proportion circuit, and when Vadj decreases, the DCDC output Vdrive increases. Conversely, when Vf decreases, vadj increases and Vdrive decreases. The closed loop regulation realizes the function of Vdrive dynamic tracking Vf.

As shown in fig. 3, the review module is composed of a follower circuit and an inverse proportion circuit.

The following circuit is composed of an operational amplifier U1B, the non-inverting input end of the U1B is connected with Vf, the inverting input end of the U1B is connected with the output end, and the following circuit utilizes the characteristics of large input impedance and small output impedance to realize impedance change. The influence of the internal resistance of the load voltage on the inverse proportional circuit is avoided, the precision of the detection loop is improved, and the influence of possible shunt of a later loop on the precision of the constant current source is avoided.

The reverse phase proportion circuit is composed of a U2B, a R1, a R2 and a R3, the resistor R2 is connected with the output end of the follower circuit and the reverse phase input end of the U2B, the resistor R1 pulls the non-inverting input end of the U2B down to the ground, and the resistor R3 is connected with the reverse phase input end and the output end of the U2B. The inverse proportional circuit realizes the functions of signal polarity inversion and gain adjustment by using depth negative feedback, and the output of the inverse proportional circuit is connected to the second input of the voltage-adjustable power supply module and is used for realizing the closed-loop adjustment of the power supply. The resistor R1 is a balance resistor, so that the bias current of the operational amplifier can not generate additional offset voltage, and the circuit precision is improved.

As shown in fig. 4, the V/I conversion module is composed of an operational amplifier, a sampling resistor, and a driving tube U28, and specifically, the driving tube is an MOS tube, a first input end D of the MOS tube is connected to an inverting input end of the operational amplifier U3B, a second input end G of the MOS tube is connected to an output end of the operational amplifier U3B through a resistor R9, an output end S of the MOS tube is connected to a load RL, and the sampling resistor R8 is connected to a driving power supply Vdrive and the inverting end of the operational amplifier U3B. The V/I conversion module realizes voltage/current conversion and constant current source output.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention. The present invention is well known in the art and can be modified and decorated without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention is subject to the claims.

Claims

1. A low-power constant current source output system, comprising:

the voltage-adjustable power supply module is used for providing a constant current source driving power supply;

the V/I conversion module is used for converting voltage/current to realize constant current source output;

and the return detection module is used for acquiring the voltage of an external load in real time and feeding back an adjusting signal to the adjustable voltage power supply module.

2. The low-power constant current source output system according to claim 1, wherein a first input terminal of the voltage-adjustable power supply module is connected to an external power supply output terminal, and a second input terminal is connected to an output terminal of the feedback detection module; the output end of the voltage-adjustable power supply module is connected with the input end of the V/I conversion module; the V/I conversion module adopts an MOS as a driving stage, a first output end of the V/I conversion module is connected with an input end of the return detection module, and a second output end of the V/I conversion module is connected with an input end of an external load; and the input end of the V/I conversion module is connected with the output of an external DAC (digital-to-analog converter) or the output of an analog circuit.

3. The low power consumption constant current source output system according to claim 2, wherein the voltage-adjustable power module employs a voltage-adjustable DCDC chip.

4. The low power consumption constant current source output system according to claim 3, wherein the feedback detection module comprises a follower circuit and an inverse proportional circuit, the follower circuit is configured by an operational amplifier, an input terminal of the follower circuit is connected to an external load, an output terminal of the follower circuit is connected to an input terminal of the inverse proportional circuit, and an output terminal of the inverse proportional circuit is connected to the second input terminal of the adjustable voltage power supply module.

5. The low-power consumption constant current source output system according to claim 4, wherein the follower circuit is formed by an operational amplifier U1B, a non-inverting input terminal of U1B is connected to a load Vf, and an inverting input terminal of U1B is connected to the output terminal; the inverse proportion circuit is composed of an operational amplifier U2B and resistors R1, R2 and R3, the resistor R2 is connected with the output end of the follower circuit and the inverse input end of the U2B, the resistor R1 pulls the non-inverting input end of the U2B down to the ground, and the resistor R3 is connected with the inverse input end and the output end of the U2B.