CN207352504U - A kind of multichannel small electric current sensor power supply circuit - Google Patents

Abstract

The utility model discloses a kind of multichannel small electric current sensor power supply circuit, including：Micro-control unit (MCU), Power Management Unit, power supply output unit, voltage detection unit and voltage feedback unit.The Power Management Unit includes power supply chip and voltage regulating device, can export adjustable voltage on demand.The voltage detection unit per voltage output all the way to carrying out voltage detecting and protection.Voltage signal is constantly back to microcontroller and is read out judgement by the voltage feedback unit.The circuit design of the utility model has applied in the automobile electronics of this department.Compared with existing power supply circuit, the utility model is with strong points for small electric current sensor, and design cost is low；Can at the same time output multi-channel voltage, meet different power demands；Circuit is relatively simple will not to be taken compared with multicomponent device space, effectively reduce area needed for circuit board；It is not interfere with each other per passage for electricity output and safely controllable, caloric value is relatively low, and antijamming capability is stronger, and electromagnetic radiation is relatively low.

Description

A kind of multichannel small electric current sensor power supply circuit

Technical field

Electrical automotive circuits technical field is the utility model is related to, is powered more particularly to a kind of multichannel small electric current sensor Circuit.

Background technology

Commercial car since automobile body is longer, cause it is distant between each sensor when mounted, harness length compared with Greatly, easily there is reversed sensor service cable positive and negative anodes, sensor feeder ear electrode cable and the short circuit of automobile batteries anode, pass The problems such as sensor service cable and short-circuit automobile batteries cathode.Further, since the electrical characteristic of small electric current sensor, passed in harness The electric signal amplitude passed is not high, and limited strength, is easily subject to external environment condition to disturb.Especially complicated automotive electronics environment, example Such as engine spark plug, high power DC electric machine, the solenoid valve of high-frequency operation, all can externally give off substantial amounts of electromagnetism Ripple.These electromagnetic radiation are easy to cause the electronic equipment of surrounding severe jamming, or even directly result in electronic equipment and stop work Work or malfunction.If these strong interference signals are sealed in small electric current sensor signal circuit, it is more likely that cause to pass The problems such as sensor data failure.It is simple by manually investigation if micro-control unit (MCU) self can not detect these failures Circuit is extremely difficult or even can not find problem place.Therefore, external sensor power supply must be controllable independently of each other and can be with Real-time diagnosis.

The each function system of vehicle electric field is finally achieved by electronic control unit (ECU).ECU is as whole The control axis of system, is handled by the signal collected to exterior various sensors, is accurately moved Make to achieve the purpose that to automatically control.Therefore, in each ECU hardware circuit, it is necessary to have a power supply for stablizing safety System.Being typically designed of electric power system (design for using packaged power management chip) can all include enabled control (can be with Freely control switching), overcurrent-overvoltage detection, the security function such as short circuit protection measures, when there is external sensor failure Or during wire short-circuiting ECU internal circuits can be protected unaffected.If such design is only to an exterior biography Sensor is powered, and truly feasible property is higher.But when outside is there are during multiple sensors, and each sensor rated voltage differs Cause, this design is just very powerless.Their supplying channels quantity is also very limited.If wherein supplying power for outside exports all the way There occurs short circuit phenomenon, will trigger higher level's power management chip internal short-circuit protection mechanism, remaining several sensor power supply Also direct power-off can therefore be involved, such system is inadequate safety and stability.In addition, common multiple-output electric power core Piece species is simultaneously few, and without certain specific aim, and price is high, according to multiple-way supply output power management chip or It is that circuit is designed using the power management chip of multiple single services output, advisability is very low.

Utility model content

In order to overcome the above-mentioned deficiencies of the prior art, the utility model provides a kind of multichannel small electric current sensor power supply electricity Road, for small electric current sensor power, can multiple-channel output, flexibly it is independent, economic and practical and safe and reliable.

The circuit includes：Micro-control unit, Power Management Unit, power supply output unit, voltage detection unit and voltage Feedback unit；The micro-control unit is connected with the Power Management Unit by I/O and can be independent to Power Management Unit Controllable, the Power Management Unit is connected with the power supply output unit, and the voltage feedback unit passes through conducting wire and power supply pipe Reason unit is connected, and the voltage detection unit is constantly obtained power supply voltage signal by conducting wire and is transmitted to micro-control unit.

The Power Management Unit includes power supply chip and voltage regulating device, can accurately adjust voltage needed for output, essence Really to 0.01 volt.And can output multi-channel voltage at the same time, meet different power demands, have one per voltage output all the way Backfeed loop is back to chip internal.The feedback end that the Power Management Unit, voltage detection unit, voltage feedback unit are formed To whether just to carry out voltage detecting and protection, the directly voltage signal of monitoring output to external sensor per voltage output all the way Often, voltage signal is constantly back to microcontroller and is read out judgement.

Technical solution is used by the utility model：Using common functional chip in signal processing, with output control Signal refers to, can at the same time output multi-channel voltage, meet different power demands.Function core is connected to the I/O pins of microcontroller The signal input part of piece, default I/O drop-down ground connection, by configuring external voltage regulating device, with the control of single-chip processor i/o foot output Signal processed is the power supply signal of magnitude of voltage needed for output outside reference pair.Microcontroller is changed to per all the way by digital-to-analog at the same time The output voltage of functional chip carries out voltage monitoring, will control what the road exported if detecting that exception occur in output voltage values Pin pulls down, and voltage is changed into 0 volt, so that closing abnormal passage supplies electricity output.Each interchannel is separate, can individually control With protection, output voltage can also flexibly be set according to external sensor parameter.

Compared with prior art, the beneficial effects of the utility model are：This technology is supplied mainly for small electric current sensor Electricity, design cost are relatively low.Circuit is relatively simple will not to be taken compared with multicomponent device space, effectively reduce area needed for circuit board.Hair Heat is relatively low, and antijamming capability is stronger, and electromagnetic radiation is relatively low.Each interchannel power supply output is separate, can individually control With protection.The design is had been used in the automotive electronics braking class product of our company, 4 rated voltages 5 of the product external connection Volt, the pressure sensor of rated current 10mA, measurement error are less than 0.005Mpa.The utility model is chip used compared to other Existing product cost savings more than 60%, supplying power for outside is safe and reliable, more economical to be applicable in.

Brief description of the drawings

Fig. 1 is the utility model circuit design block diagram；

Fig. 2 is the power supply circuit of the utility model.

Embodiment

The following is a combination of the drawings in the embodiments of the present utility model, and the technical scheme in the embodiment of the utility model is carried out Clearly and completely describe, it is clear that described embodiment is only the utility model part of the embodiment, rather than whole realities Apply example.Based on the embodiment in the utility model, those of ordinary skill in the art institute without making creative work The every other embodiment obtained, shall fall within the protection scope of the present invention.

For details referring to Fig. 2, circuit shown in Fig. 2 is the power supply circuit that the utility model embodiment provides, and whole system is adopted Powered with 12 volts of DC power supplies.This circuit is mainly made of 3 parts：Control terminal, occur end and feedback end.

U1 in control terminal such as figure, suitable for any microcontroller.This example selects 3.3 volts to power to microcontroller, this is common Microcontroller supply voltage, the high level voltage signal voltage value of the I/O mouths output of microcontroller are approximately equal to supply voltage, it is believed that The high level that I/O1~4 export is 3.3 volts.

It is the acp chip in the utility model power circuit designing scheme that end, which occurs, is U2 in figure, its supply voltage Scope is wider, and this example uses 12 volts of common system voltage in automotive electronics to supply power for.It is defeated that the chip can be applied to 4 road voltages Go out requirement, be required for a backfeed loop to be back to chip internal per voltage output all the way, see FeedBack in figure.

Feedback end is mainly to carrying out voltage monitoring and the circuit of protection per voltage output all the way, and directly monitoring is exported to outer Whether 4 voltage signals of portion's sensor are normal, and voltage signal constantly is back to microcontroller is read out judgement.

S1~S4 is external pressure sensor in figure, 5 volts, rated current 10mA of the model pressure sensor rated voltage, Two-wire system, does not differentiate between positive and negative anodes.R1~R4 resistances are specifically as follows 10K Ω in figure, primarily to ensuring to work as microcontroller I/O mouthfuls of no signal outputs or microcontroller failure, which are run, cuts off external sensor power supply when flying.C1~C4 capacitor's capacities can be with figure Specially 100nF, pressure-resistant to need be only greater than 3.3 volts, this four capacitances are referred to as decoupling capacitor, ensure power supply control end letter Number stabilization.C5~C8 capacitor's capacities can be specific to 100nF or more in figure, and main function is that regulated output voltage prevents ripple It is dynamic, remove the high-frequency noise in signal.If external sensor is often also needed to consider that ESD is quiet when in use by human contact etc. Electricity protection, because chip itself the antistatic grade that the utility model uses is not high, if the circuit applies to similar hold and sets Standby wait need to also be in C5~C8 capacitance terminal parallel connection ESD protective devices when designing.

Operation principle

A ratio is obtained firstly the need of by the computing of doing sums of the load voltage value of sensor and single-chip processor i/o output voltage values Example coefficient, is adjusted FeedBack voltage feedback circuits by the coefficient.Four voltages control I/O pins of microcontroller are necessary Can be external output mode by software configuration, four control signal input phases chip used with the utility model respectively Even.It is Non voltage output, it is necessary to when powering to sensor since the presence of R1~R4 resistance does not configure system external before I/O, Only need to draw high its corresponding I/O pin, that is, export high level signal.Chip enables after capturing the useful signal of the passage The generation circuit of the channel interior, performs the proportionality coefficient that feedback circuit provides, externally fed is inputted and carries out internal conversion most Become the nominal supply voltages of sensor eventually.Meanwhile once output voltage is effective, when sensor is started to work, power supply circuit Voltage detecting circuit also begins to work, constantly handles magnitude of voltage and is sent to microcontroller progress analog-to-digital conversion, microcontroller judges Whether current output voltage meets proportionality coefficient, and voltage is with the presence or absence of abnormal.Once electric voltage exception, microcontroller is by abnormal passage Corresponding I/O pins drag down, that is, export low level, and externally fed voltage decreases about 0, and sensor is stopped.The feelings Under condition, failure code can be sent and be diagnosed for staff by microcontroller by various communication modes such as CAN, and work people Member can easily judge it is which sensor fault, be overvoltage protection or short-circuit protection.

The utility model embodiment provide power supply circuit by single chip machine controlling circuit, acp chip voltage generating circuit, Signal feedback loop forms.Compared with existing power supply circuit, control is simple, practical and convenient, of low cost, individually controllable.As outside Portion's number of sensors is more, and this programme can also continue to extended channel number.This circuit can apply to as a circuit module In other control system, can also separately made power supply module use on other circuit boards, it might even be possible to be packaged into one New power supply chip uses.

The above, is only specific embodiment of the present utility model, but the scope of protection of the utility model is not limited to In this, any one skilled in the art can readily occur in change in the technical scope that the utility model discloses Or replace, it should be covered within the scope of the utility model.Therefore, the scope of protection of the utility model should be described with power Subject to the protection domain that profit requires.

Claims (3)

1. a kind of multichannel small electric current sensor power supply circuit, it is characterised in that the circuit includes：Micro-control unit (MCU), electricity Source control unit, power supply output unit, voltage detection unit and voltage feedback unit；The micro-control unit passes through I/O and institute State Power Management Unit connection and can be individually controllable to Power Management Unit, the Power Management Unit and described supply electricity output Unit is connected, and the voltage feedback unit is connected by conducting wire with Power Management Unit, and the voltage detection unit passes through conducting wire Constantly obtain power supply voltage signal and be transmitted to micro-control unit.

A kind of 2. multichannel small electric current sensor power supply circuit according to claim 1, it is characterised in that the power management Unit includes power supply chip and voltage regulating device, can accurately adjust voltage needed for output, and output voltage precision is 0.01 volt；Can With output multi-channel voltage at the same time, meet different power demands, there is a backfeed loop to be back to chip per voltage output all the way It is internal.

3. a kind of multichannel small electric current sensor power supply circuit according to claim 2, it is characterised in that by power management list The feedback end that member, voltage detection unit, voltage feedback unit are formed per voltage output all the way to carrying out voltage detecting and protection, directly It is whether normal to the voltage signal of external sensor to connect monitoring output, constantly voltage signal is back to microcontroller and is read out and is sentenced It is disconnected.