CN202167829U - Over-temperature protection terminal controlled by hardware - Google Patents

Abstract

The utility model discloses an over-temperature protection terminal controlled by hardware, which comprises a temperature detection unit, a direct current to direct current (DC-DC) power supply chip and a control unit. The temperature detection unit is used for detecting temperature of a system to be detected and converting detected temperature of the system to be detected into voltage signals. The DC-DC power supply chip is used for supplying power to the system to be detected. The control unit is used for receiving the voltage signals output by the temperature detection unit and controlling whether to supply power to the system to be detected. The temperature detection unit, the control unit and the DC-DC power supply chip are connected sequentially. The over-temperature protection control terminal is pure hardware, when the temperature is higher than a preset limit value, the over-temperature protection terminal controlled by the hardware directly shuts down a main power supply of the system to protect the system; and when the temperature recovers to a reasonable range, the power supply is opened automatically, and the system can start up to work smoothly and effectively.

Description

The overheat protector terminal of hardware controls

Technical field

The utility model relates to a kind of overheat protector terminal, particularly relates to a kind of hardware controls overheat protector terminal.

Background technology

Along with the generation and the development of large scale integrated circuit, the integrity problem of heat radiation and integrated circuit more and more receives people's attention.Because integrated circuit requires arithmetic speed more and more faster, frequency is also increasingly high, so just inevitably produces a large amount of thermal lossess; Moreover the parameter temperature influence of elements such as the resistance of integrated circuit, electric capacity and transistor thereof is very big, if can not well system temperature be controlled, system can't work normally and efficiently.

Temperature control problem when system works is paid close attention in a large amount of research; Seldom exceed after the controlled range research of how system being protected the aspect relevant for temperature; Particularly some large scale integrated circuit systems or the bigger electromechanical assembly of some quantities of heat production; In case temperature is crossed the higher position and maybe system be damaged, cause very big economic loss and cause unnecessary trouble.Therefore the research at a kind of hardware controls overheat protector terminal just seems particularly necessary.

The utility model content

The utility model is in order to overcome circuit more of the prior art can't be when system temperature exceeds normal temperature range carry out timely and effective protection to system defective; A kind of detection system temperature that has is provided; And temperature information changed into high low voltage signal, and then the overheat protector terminal of the hardware controls that system is in time protected.

The utility model solves above-mentioned technical problem through following technical proposals:

A kind of overheat protector terminal of hardware controls, its characteristics are that the overheat protector terminal of this hardware controls comprises:

One temperature detecting unit, be used to detect one treat examining system temperature, and the detected said temperature inversion of examining system of treating become a voltage signal;

One DC-DC power supply chip is used for supplying power to the said examining system of treating;

One control unit, whether the said voltage signal and the control that are used to receive said temperature detecting unit output give the said examining system power supply of treating;

Wherein said temperature detecting unit, said control unit and said DC-DC power supply chip connect successively.

Preferably; This temperature detecting unit is: an end of one the one PTC thermistor is connected with a power supply; The other end of the one PTC thermistor is connected with ground through one the 6th resistance, also is connected with ground through one second electric capacity, is connected with a homophase input of an operational amplifier through one the 5th resistance again; One output of this operational amplifier is connected with one first output of this temperature detecting unit; One the 4th resistance cross-over connection is in the said in-phase input end of said operational amplifier and the said output of said operational amplifier, and an end of one the 3rd resistance links to each other with a power supply, and the other end of the 3rd resistance links to each other with said first output of said temperature detecting unit circuit; One end of one first resistance links to each other with said power supply; The other end of this first resistance is through one second grounding through resistance, and an inverting input of said operational amplifier is connected between said first resistance and said second resistance, and one first electric capacity and said second resistance are in parallel.

Preferably; This temperature detecting unit is: an end of 1 the 13 resistance is connected with a power supply; The other end of said the 13 resistance is connected with ground through one the 2nd PTC thermistor; Also be connected with ground through one the 4th electric capacity, be connected with an inverting input of an operational amplifier through one the 7th resistance again, a homophase input of this operational amplifier links to each other with an end of one the 3rd electric capacity through one the 8th resistance; The 3rd electric capacity other end ground connection; One output of said operational amplifier is connected with an end of 1 the tenth resistance, and the other end of the tenth resistance links to each other with one second output of said temperature detecting unit, and the said in-phase input end of said operational amplifier links to each other with said second output of said temperature detecting unit through one the 9th resistance; One end of 1 the 11 resistance links to each other with a power supply; The other end of the 11 resistance is through 1 the 12 grounding through resistance, and two voltage-stabiliser tubes all have a negative electrode, and the said negative electrode of said two voltage-stabiliser tubes is connected to form a voltage clipping element; This voltage clipping element one end links to each other with said second output of said temperature detecting unit circuit, and the said voltage clipping element other end is connected between said the 11 resistance and said the 12 resistance.

Preferably, said temperature detecting unit is made up of a PTC thermistor test section and a hysteresis voltage comparator and one of which filter function circuit, and said PTC thermistor test section, hysteresis voltage comparator and filter function circuit thereof connect successively.

Preferably; Said control unit is a N channel-type metal-oxide-semiconductor; One grid of this N channel-type metal-oxide-semiconductor is connected in one second output of said temperature detecting unit circuit; The one source pole of this N channel-type metal-oxide-semiconductor is connected with ground, and a drain electrode of this N channel-type metal-oxide-semiconductor is connected an Enable Pin of DC-DC power supply chip.

The positive progressive effect of the utility model is:

The utility model provides a kind of overheat protector control terminal of pure hardware, when temperature surpasses when presetting limiting value, the general supply of system will be directly turn-offed at the overheat protector terminal of this hardware controls, and system hardware is protected; After temperature returned to reasonable range, opening power made system's effectively work smoothly automatically again.Therefore solved owing to temperature can not in time be protected the problem that causes system failure to be measured and inefficacy to system when too high, prolonged the useful life of system.

Description of drawings

Fig. 1 is the module map at the hardware controls overheat protector terminal of the utility model.

Fig. 2 is the temperature detecting unit circuit diagram of preferred embodiment at the hardware controls overheat protector terminal of the utility model.

Fig. 3 is the temperature voltage transmission characteristic figure of preferred embodiment at the hardware controls overheat protector terminal of the utility model.

Fig. 4 is the control unit circuit figure of preferred embodiment at the hardware controls overheat protector terminal of the utility model.

Fig. 5 is another circuit diagram of temperature detecting unit at the hardware controls overheat protector terminal of the utility model.

Embodiment

Provide the utility model preferred embodiment below in conjunction with accompanying drawing, to specify the technical scheme of the utility model.

The composition module map at a kind of hardware controls overheat protector terminal as shown in Figure 1, the overheat protector terminal of hardware controls comprises:

One temperature detecting unit, be used to detect one treat examining system temperature, and the detected said temperature inversion of examining system of treating become a voltage signal;

One DC-DC power supply chip is used for supplying power to the said examining system of treating;

One control unit, whether the said voltage signal and the control that are used to receive said temperature detecting unit output give the said examining system power supply of treating;

Wherein said temperature detecting unit, said control unit and said DC-DC power supply chip connect successively.

Fig. 2 is the temperature detecting unit circuit diagram of preferred embodiment at the hardware controls overheat protector terminal of the utility model, and the temperature detecting unit circuit specifically describes as follows:

One PTC thermistor R _T21An end and a power supply V _CcBe connected this PTC thermistor R _T21The other end through a resistance R ₂₆Be connected with ground, also through a capacitor C ₂₂Be connected with ground, again through a resistance R ₂₅Be connected an output V of an output of this operational amplifier and this temperature detecting unit with a homophase input of an operational amplifier _OutBe connected a resistance R ₂₄Cross-over connection is in the said in-phase input end of said operational amplifier and the said output of said operational amplifier, a resistance R ₂₃An end and a power supply V _CcLink to each other this resistance R ₂₃The other end and the said output V of said temperature detecting unit circuit _OutLink to each other a resistance R ₂₁An end and said power supply V _CcLink to each other this resistance R ₂₁The other end through a resistance R ₂₂Ground connection, an inverting input of said operational amplifier is connected in said resistance R ₂₁With said resistance R ₂₂Between, a capacitor C ₂₁With said resistance R ₂₂Be in parallel.

The circuit of said temperature detecting unit is made up of three parts on the whole: filter function circuit 202 that a PTC thermistor test section 201 and an electric capacity are formed and one of which have bistable voltage comparator 203 and form; Bistable voltage comparator is the hysteresis voltage comparator.

The temperature detecting unit operation principle at this hardware controls overheat protector terminal in the present embodiment is following:

Described temperature detecting unit comprises that comparator is operational amplifier LM393 (National Semiconductor's production), wherein can set R ₂₁=R ₂₂=100K, then V _REF=V _CC/ 2.R ₂₃＝R ₂₄＝47K。R _T21Select PTC (Positive Temperature Coefficient, positive temperature coefficient) thermistor, with R _T21Be placed on the next door of CPU or the back of CPU, resistance changes along with the variation of temperature of CPU.It is T that existing hypothesis is worked as temperature ₂The time, resistance is R ₂₇, temperature is T ₁The time resistance be R ₂₈Through calculating through adjustment R ₂₅And R ₂₆The output of controlling LM393 for suitable resistance is as shown in Figure 3, makes that working as temperature equals T ₂The time, the in-phase input end voltage of LM393 is V _Th2, the temperature detecting unit output voltage is V _OH, wait until T when temperature reduces ₁The time, the in-phase end input voltage of LM393 is V _Th1, the temperature control unit output voltage is V _OLConcrete calculating is following.

When temperature rises to T ₂The time, V _OutOutput voltage is assumed to be V _OH, this moment, the in-phase end voltage of LM393 was U+, end of oppisite phase voltage is U-.This moment thermistor R _T21Resistance be R ₂₇, then have:

$\frac{V_{\mathrm{CC}}-U_{+}}{R_{23}+R_{24}}=-\frac{\frac{R_{26}}{R_{26}+R_{27}}\×V_{\mathrm{CC}}-U_{+}}{R_{25}}---1-1$

$U_{-}=\frac{R_2}{R_{21}+R_{22}}\×V_{\mathrm{CC}}=V_{\mathrm{CC}}/2---1-2$

U _-＝U ₊ 1-3

$\frac{V_{\mathrm{CC}}/2}{R_{23}+R_{24}}=-\frac{\frac{R_{26}}{R_{26}+R_{27}}\×V_{\mathrm{CC}}-V_{\mathrm{CC}}/2}{R_{25}}---1-4$

$V_{\mathrm{OH}}=V_{\mathrm{CC}}-\frac{V_{\mathrm{CC}}/2}{R_{23}+R_{24}}\×R_{23}=0.75\×V_{\mathrm{CC}}---1-5$

When temperature drops to T ₁The time, V _OutOutput voltage is assumed to be V _OL, this moment, the in-phase end voltage of LM393 was U ₊, end of oppisite phase voltage is U _-This moment thermistor R _T21Resistance be R ₂₈, suppose R ₂₅And R ₂₆Voltages at nodes is U _In, then have:

$\frac{V_{\mathrm{OL}}-U_{+}}{R_{24}}=-\frac{U_{\mathrm{IN}}-U_{+}}{R_{25}}---2-1$

$U_{-}=\frac{R_{22}}{R_{21}+R_{22}}\×V_{\mathrm{CC}}=V_{\mathrm{CC}}/2---2-2$

U _-＝U ₊ 2-3

V _OL＝0

$\frac{\mathrm{VCC}-U_{\mathrm{IN}}}{R28}=\frac{U_{\mathrm{IN}}}{R26}+\frac{U_{\mathrm{IN}}-U_{+}}{R25}---2-4$

Present R ₂₃And R ₂₄, and PTC thermistor R _T21In temperature is T ₂And T ₁The time resistance R ₂₇With R ₂₈Be known, V _CCVoltage be directly connected to power supply adaptor and cell input terminal, i.e. the input of the DC-DC power supply chip of system front end too greatly also can adopt proper resistor to carry out the dividing potential drop modulation like voltage.The 1-4 formula can be provided through equation 1-1,1-2,1-3, suitable R can be obtained through 2-1,2-2,2-3,2-4 formula and equation 1-4 formula simultaneously ₂₅With R ₂₆Value, thereby accomplish the parameter setting of this circuit.C wherein ₂₁With C ₂₂Can select the electric capacity of 1000pF, also can adjust a little.Mainly be used for playing the effect of voltage regulation filtering.Certain R ₂₃With R ₂₄Value also can according to actual adjustment of being correlated with again row calculate R ₂₅With R ₂₆Value.

Fig. 3 is the temperature voltage transmission characteristic of temperature detecting unit output of preferred embodiment at the hardware controls overheat protector terminal of the utility model.Obtain from theory analysis, the bistable voltage comparator is in temperature T ₂The time, by formula 1-5 output HIGH voltage value V _OH=0.75V _CC, in temperature T ₁The time, by formula 1-3 output LOW voltage value V _OL=0.

Fig. 4 is the control unit circuit figure of preferred embodiment at the hardware controls overheat protector terminal of the utility model; Control unit is mainly realized controlled function through a N channel-type metal-oxide-semiconductor Q1, and the grid of this N channel-type metal-oxide-semiconductor is connected in the output V of temperature detecting unit circuit _Out, source electrode is connected with ground, and drain electrode is connected the Enable Pin of DC-DC power supply chip.The operation principle of control unit is described as: when temperature detecting unit is output as V _OLThe time, Q1 turn-offs, and the Enable Pin voltage of the DC-DC power supply chip of rear end is directly provided by the input power supply, and this moment, operate as normal was given system's normal power supply; When temperature detecting unit is output as V _OHThe time, the Q1 conducting makes the Enable Pin EN of DC-DC be input as GND, thereby DC-DC can not be worked, thereby back-end system can not be opened, this moment, temperature began to descend.The connection of DC-DC power supply chip with close by the control signal control that receives Enable Pin, and the voltage of power supply and adapter is dropped to the spendable scope of system, and whether gives according to the control signal decision and to treat that examining system supplies power.

Fig. 5 is another circuit diagram of temperature detecting unit of preferred embodiment at the hardware controls overheat protector terminal of the utility model, and the circuit structure of this temperature detecting unit specifically describes as follows:

One resistance R ₅₇An end and a power supply V _CcBe connected said resistance R ₅₇The other end through a PTC thermistor R _T51Be connected with ground, also through a capacitor C ₅₂Be connected with ground, again through a resistance R ₅₁Be connected with an inverting input of an operational amplifier, a homophase input of this operational amplifier is through a resistance R ₅₂With a capacitor C ₅₁An end link to each other this capacitor C ₅₁Other end ground connection, an output of said operational amplifier and a resistance R ₅₄An end be connected this resistance R ₅₄The other end and an output V of said temperature detecting unit _OutLink to each other, the said in-phase input end of said operational amplifier is through a resistance R ₅₃Said output V with said temperature detecting unit _OutLink to each other a resistance R ₅₅An end and a power supply V _CcLink to each other this resistance R ₅₅The other end through a resistance R ₅₆Ground connection, two voltage-stabiliser tubes all have a negative electrode, and the said negative electrode of said two voltage-stabiliser tubes is connected to form a voltage clipping element D _Z, this voltage clipping element D _ZThe said output V of one end and said temperature detecting unit circuit _OutLink to each other said voltage clipping element D _ZThe other end is connected in said resistance R ₅₅With said resistance R ₅₆Between.

The circuit of said temperature detecting unit is made up of three parts on the whole: filter function circuit 502 that a PTC thermistor test section 501 and an electric capacity are formed and one of which have bistable voltage comparator 503 and form; Bistable voltage comparator is the hysteresis voltage comparator.

The temperature detecting unit operation principle at this hardware controls overheat protector terminal is following:

The threshold value of forward process does

$V_{\mathrm{th}1}=(1+\frac{R_{52}}{R_{53}})U_R-\frac{R_{52}}{R_{53}}{U}_l$

The threshold value of negative sense process does

$V_{\mathrm{th}2}=(1+\frac{R_{52}}{R_{53}})U_R-\frac{R_{52}}{R_{53}}{U}_h$

Can obtain the return difference of hysteresis voltage comparator thus

$\▿V_{\mathrm{th}}=V_{\mathrm{th}1}-V_{\mathrm{th}2}=\frac{R_{52}}{R_{53}}(U_h-U_l)=\frac{2R_{52}}{R_{53}}{U}_Z$

$U_h=\frac{R_{56}}{R_{55}+R_{56}}{V}_{\mathrm{cc}}+U_Z$

$U_l=\frac{R_{56}}{R_{55}+R_{56}}{V}_{\mathrm{cc}}-U_Z$

Can know by above analysis, change R ₅₂Value can change the size of return difference, is used for the scope of initialization system control temperature; Adjustment U _RThough value can not have influence on the size of return difference still can be so that the transmission characteristic shift to right or left of hysteresis voltage comparator be used for the initial value that initialization system is controlled temperature.Through regulating resistance R ₅₅With R ₅₆Resistance the output characteristic curve integral body of hysteresis voltage comparator is moved up and down so that output is suitable for the grid-control voltage of Q1 among Fig. 4.Therefore, the adjustable range of temperature can be converted into the control to hysteresis voltage comparator return difference, and the size of return difference is through regulating resistance R ₅₂Or R ₅₃Resistance set.The common basis of choosing of temperature regulating range

treats that examining system and safe requirement thereof confirm.

The temperature detecting unit workflow at this hardware controls overheat protector terminal is following:

When system temperature is low, PTC thermistor R _T51Resistance lower, the operational amplifier input terminal voltage is a low level, the output voltage V in the time of usually less than hysteresis voltage comparator low level _Th2When the system works temperature raises, will cause PTC thermistor R _T51Resistance raise, when temperature is increased to the high level V that magnitude of voltage reaches threshold voltage _Th1The time, the output of hysteresis voltage comparator will reach high level.PTC thermistor R like this _T51Temperature variation is changed into voltage variety and then control hysteresis voltage comparator, and the voltage-transfer characteristic of hysteresis voltage comparator and temperature transmission characteristic have been set up functional relation like this.

Though more than described the embodiment of the utility model, it will be understood by those of skill in the art that these only illustrate, the protection range of the utility model is limited appended claims.Those skilled in the art can make numerous variations or modification to these execution modes under the prerequisite of principle that does not deviate from the utility model and essence, but these changes and modification all fall into the protection range of the utility model.

Claims (5)

1. the overheat protector terminal of a hardware controls is characterized in that, the overheat protector terminal of this hardware controls comprises:

One temperature detecting unit, be used to detect one treat examining system temperature, and the detected said temperature inversion of examining system of treating become a voltage signal;

One DC-DC power supply chip is used for supplying power to the said examining system of treating;

One control unit, whether the said voltage signal and the control that are used to receive said temperature detecting unit output give the said examining system power supply of treating;

Wherein said temperature detecting unit, said control unit and said DC-DC power supply chip connect successively.

2. the overheat protector terminal of hardware controls as claimed in claim 1 is characterized in that, this temperature detecting unit is: a PTC thermistor (R _T21) an end and a power supply (V _Cc) be connected this PTC thermistor (R _T21) the other end through a resistance (R ₂₆) be connected with ground, also through an electric capacity (C ₂₂) be connected with ground, again through a resistance (R ₂₅) be connected an output (V of an output of this operational amplifier and this temperature detecting unit with a homophase input of an operational amplifier _Out) be connected a resistance (R ₂₄) cross-over connection is in the said in-phase input end of said operational amplifier and the said output of said operational amplifier, a resistance (R ₂₃) an end and a power supply (V _Cc) link to each other this resistance (R ₂₃) the other end and the said output (V of said temperature detecting unit circuit _Out) link to each other a resistance (R ₂₁) an end and said power supply (V _Cc) link to each other this resistance (R ₂₁) the other end through a resistance (R ₂₂) ground connection, an inverting input of said operational amplifier is connected in said resistance (R ₂₁) and said resistance (R ₂₂) between, an electric capacity (C ₂₁) and said resistance (R ₂₂) be in parallel.

3. the overheat protector terminal of hardware controls as claimed in claim 1 is characterized in that, this temperature detecting unit is: a resistance (R ₅₇) an end and a power supply (V _Cc) be connected said resistance (R ₅₇) the other end through a PTC thermistor (R _T51) be connected with ground, also through an electric capacity (C ₅₂) be connected with ground, again through a resistance (R ₅₁) be connected with an inverting input of an operational amplifier, a homophase input of this operational amplifier is through a resistance (R ₅₂) and an electric capacity (C ₅₁) an end link to each other this electric capacity (C ₅₁) other end ground connection, an output of said operational amplifier and a resistance (R ₅₄) an end be connected this resistance (R ₅₄) the other end and an output (V of said temperature detecting unit _Out) link to each other, the said in-phase input end of said operational amplifier is through a resistance (R ₅₃) with the said output (V of said temperature detecting unit _Out) link to each other a resistance (R ₅₅) an end and a power supply (V _Cc) link to each other this resistance (R ₅₅) the other end through a resistance (R ₅₆) ground connection, two voltage-stabiliser tubes all have a negative electrode, and the said negative electrode of said two voltage-stabiliser tubes is connected to form a voltage clipping element (D _Z), this voltage clipping element (D _Z) the said output (V of an end and said temperature detecting unit circuit _Out) link to each other said voltage clipping element (D _Z) other end is connected in said resistance (R ₅₅) and said resistance (R ₅₆) between.

4. like the overheat protector terminal of claim 2 or 3 described hardware controls; It is characterized in that; Said temperature detecting unit is made up of a PTC thermistor test section and a hysteresis voltage comparator and one of which filter function circuit, and said PTC thermistor test section, hysteresis voltage comparator and filter function circuit thereof connect successively.

5. the overheat protector terminal of hardware controls as claimed in claim 1 is characterized in that, said control unit is a N channel-type metal-oxide-semiconductor, and a grid of this N channel-type metal-oxide-semiconductor is connected in an output (V of said temperature detecting unit circuit _Out), the one source pole of this N channel-type metal-oxide-semiconductor is connected with ground, and a drain electrode of this N channel-type metal-oxide-semiconductor is connected an Enable Pin of DC-DC power supply chip.

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