Radio temperature sensor chip
Technical field
The present invention relates to a kind of radio temperature sensor chip.
Background technology
Enter after 21 century, self-energizing intelligent wireless temperature sensor just towards high accuracy, multi-functional, bus standard,
High reliability and the high-tech direction such as safety, exploitation virtual-sensor and network sensor, development monolithic temp measuring system are fast
Speed development.
Traditional radio temperature sensor typically uses battery to power, although the energy storage density of battery and service life along with
Technological progress improves constantly, but still suffers from some energy supply defects that cannot overcome, such as energy supply restricted lifetime, need recharge,
Volume is bigger with quality, can not fully meet the demand for development of wireless sensor network.Along with wireless sensor network
Extensively application, interstitial content is more and more huger, uses the defect of battery power supply mode further to show.In recent years, self energizing technology
Being suggested as a kind of method that can fundamentally solve wireless sensor network node energy supply problem, it is a kind of by collecting
The energy of other forms convert thereof into electric energy in surrounding, for sensor and other electronic equipment provide safe and stable,
Efficiently, the electric energy supply technology limited without the life-span in theory.The advantage of self energizing technology maximum is that wireless senser may utilize
Energy in surrounding supplies as the energy of self, thus has broken away from the dependence to electrical network.Because the self-supporting of its uniqueness
Feature, the developing direction of coincidence senser and industry need, and its development prospect is the most wide.
Michiel A. P. Pertijs in 2005 etc. have delivered high-precision intelligent temperature sensor, its principle be based on
The PTAT voltage that triode transistor produces, by sigma-delta formula A/D converter, it is achieved that from the 3 σ errors of-50 DEG C to 120 DEG C only
For the intelligent temperature sensor of ± 0.5 DEG C;Faith Kocer in 2006 et al. achieves and passes with wireless temperature signal-powered for RF
Sensor, wireless transmit frequency is 2.3 GHz, stand-by power consumption 5 μ A, power 5mA when launching signal, but communication distance is shorter;
Fabio Zito in 2010 etc. have delivered for biomedical radio temperature sensor, and this chip uses triode transistor to produce
PTAT voltage, serves data to radio-frequency module by 8bit digital to analog converter and launches, and radio-frequency antenna is integrated in core by this chip
The miniaturization of chip is achieved on sheet.The research of above academia the most tentatively achieves temperature measurement circuit, radio communication circuit
Integrated, but the self-energizing of the most unrealized system, and research is not to be directed to electrical power transmission system mostly, without reference to anti-dry
Disturb the research contents of the aspects such as design.
From the point of view of the investigation situation of overseas enterprise's product, the chip that offshore company provides the most all lays particular emphasis on radio communication
Function individually realizes with a chip, such as NRF2401, TI company of ADF7021, Nordic company of ADI company
CC1100 etc..During composition wireless temperature sensing system, in addition it is also necessary to the most integrated independent ADC and processor chips etc., this
The implementation of sample has bigger Universal and scalability, but, this mode will cause the volume of system, cost relatively
High.It addition, the chip of offshore company's exploitation is typically the radio band planning for the whole world, only only a few product can cover
The 470MHz of China measures frequency range, there is presently no the chip of a offshore company disclosure satisfy that requirements at the higher level take energy, thermometric,
AD conversion, radio communication and Networking protocol process.
Owing to the IC design industry development of China is the most later, the designed capacity at chip is leavened dough advanced with external
Level disparity is relatively big, and especially in field of power, the most domestic self-energizing radio temperature sensor equipment is mainly by purchasing
Buy foreign chip to assemble, the self-energizing wireless temperature sensing special chip with Low Power High Performance of autonomous Design research and development
Not yet there is play-by-play, but also have made some progress in some field, but function is limited, it is impossible to meet the demand in market.
Summary of the invention
It is an object of the invention to provide a kind of radio temperature sensor chip, mainly lack present in solution prior art
Weary a kind of safe and reliable, radio temperature sensor chip that power consumption is relatively low, it is impossible to the problem meeting technology growth requirement.
To achieve these goals, the technical solution used in the present invention is as follows:
Radio temperature sensor chip, including:
Power Management Unit, supports that front end self-energizing installation's power source input and external power supply input, uses high voltage bearing
LDMOS pipe is designed as LDO structure;
Temperature sensor unit, the ambient temperature around detection chip, and overheat protector is produced when temperature is higher than threshold value
Signal;
Bandgap reference cell, provides to AD conversion unit within the temperature range of setting and stablizes constant DC reference electricity
Pressure, and provide stable voltage or current offset for other unit in chip;
ADC unit, gradually compares the reference signal that the signal sampled and bandgap reference cell provide, and draws every
One-bit digital transformation result, it is achieved the AD conversion of signal;
Live detection unit, it is judged that equipment to be detected is the most charged;
Transmit Receive Unit, carries out signal transmitting and receiving and process;
Described Power Management Unit, temperature sensor unit, bandgap reference cell, ADC unit, live detection unit and penetrate
Frequently Transmit-Receive Unit all integrates.
Further, described Transmit Receive Unit includes GFSK radio frequency sending set, the letter launching GFSK radio frequency sending set
Number GFSK radio-frequency transmitter being received, and the signal received by GFSK radio-frequency transmitter carries out the process list that processes
Unit.
Described GFSK radio frequency sending set realizes based on a decimal N-type frequency synthesizer;Described GFSK radio-frequency transmitter bag
Include be sequentially connected low-noise amplifier, down-conversion mixer, complex bandpass filters, the limit that is made up of N level logafier
Width device and the ADC transducer carrying out signal AD conversion.
Specifically, described Power Management Unit includes the biasing circuit being connected with power input, source electrode and biased electrical
The metal-oxide-semiconductor M3 that road is connected, grid is all connected with the drain electrode of metal-oxide-semiconductor M3 and source electrode interconnective metal-oxide-semiconductor M1 and metal-oxide-semiconductor M2, collection
The audion Q1 that electrode is connected with the drain electrode of metal-oxide-semiconductor M1, emitter stage is connected by the emitter stage of resistance R1 and audion Q1, current collection
The triode Q2 that pole is connected with the drain electrode of metal-oxide-semiconductor M2, source electrode is connected with the drain electrode of metal-oxide-semiconductor M2, grid passes through resistance R3 and three poles
The metal-oxide-semiconductor M4 that the base stage of pipe Q2 is connected, the audion Q3 that colelctor electrode is connected with the grid of metal-oxide-semiconductor M4, base stage is with audion Q3's
Base stage be connected audion Q4, the metal-oxide-semiconductor M8 that source electrode is connected with biasing circuit, the grid with metal-oxide-semiconductor M4 that drains is connected, grid and
The metal-oxide-semiconductor M7 that the grid of metal-oxide-semiconductor M8 is connected, drain electrode is connected with the colelctor electrode of audion Q4, source electrode is connected with the source electrode of metal-oxide-semiconductor M7
Metal-oxide-semiconductor M6, drain and the metal-oxide-semiconductor M5 that drain electrode is connected, source electrode is connected with the grid of metal-oxide-semiconductor M4 of metal-oxide-semiconductor M6.
Wherein, described temperature sensor unit includes PTAT current source, and the temperature sensor being connected with PTAT current source is defeated
Go out circuit, the thermal-shutdown circuit being connected with temperature sensor output circuit.
In the present invention, described PTAT current source includes base stage interconnective audion Q12 and audion Q32, base stage with
The audion Q22 that the emitter stage of audion Q32 is connected, colelctor electrode is connected with the emitter stage of audion Q12, base stage and audion
The audion Q42 that the emitter stage of Q12 is connected, colelctor electrode is connected with the emitter stage of audion Q32, and it is connected to audion Q22
Emitter stage and ground between resistance R12.
Further, described bandgap reference cell include series connection slide rheostat R7a, resistance R8a, resistance R8b and
Slide rheostat R7b, in-phase input end is connected with the sliding end of slide rheostat R7a, inverting input and slide rheostat R7b
Sliding end be connected operational amplifier T, base stage interconnective audion Q13, audion Q23, audion Q43 and audion
Q53, emitter stage is connected between resistance R8a and resistance R8b, base stage is connected to the three of audion Q53 colelctor electrode by resistance R83
Pole pipe Q33, the colelctor electrode of described audion Q13 is connected with the fixing end of slide rheostat R7a, emitter stage by resistance R13 with
The emitter stage of audion Q23 is connected, and the colelctor electrode of described audion Q23 is connected with the fixing end of slide rheostat R7b.
Compared with prior art, the method have the advantages that
(1) Power Management Unit in the present invention had both supported that the power supply of energy taking device inputted, and also supported the defeated of external power supply
Enter, and use in technique and can be designed by high voltage bearing LDMOS pipe, thus adapt to the temperature survey under varying environment, and
Ambient temperature can be measured by chip by the temperature sensor unit of self, it is also possible to uses external temperature to measure
Sensor measures, and uses flexibly, applied widely.
(2) in the present invention, by the ingehious design to bandgap reference cell so that chip can be wanted in technology by steady operation
Within the temperature range of asking, and provide reliable voltage or current offset for other circuit, thus be greatly enhanced whole chip
Temperature reliability.
(3), in the present invention, use successive approximation structure to realize the AD conversion of temperature signal, there is simple in construction, low one-tenth
Basis, the advantage of low-power consumption, and by Transmit Receive Unit being designed as the heterodyne architecture of Low Medium Frequency, effectively reduce chip
Power consumption and cost, solve local-oscillator leakage in zero intermediate frequency reciver, even nonlinearity, direct current offset, flicker noise and lost by I/Q
Join the big problems such as impact.
(4) present configuration is simple, it is ingenious to design, working stability, cost performance are higher, have prominent substantive distinguishing features and
Marked improvement, is suitable for large-scale promotion application.
Accompanying drawing explanation
Fig. 1 is the enforcement schematic diagram of the present invention.
Fig. 2 is the circuit theory diagrams of Power Management Unit in the present invention.
Fig. 3 is the circuit theory diagrams of temperature sensor unit in the present invention.
Fig. 4 is the circuit theory diagrams of bandgap reference cell in the present invention.
Detailed description of the invention
The invention will be further described with embodiment below in conjunction with the accompanying drawings, and embodiments of the present invention include but not limited to
The following example.
Embodiment
In order to solve to lack present in prior art a kind of safe and reliable, radio temperature sensor core that power consumption is relatively low
Sheet, it is impossible to the problem meeting technology growth requirement, as shown in Fig. 1 ~ 4, the invention provides a kind of security performance height, reliability
By force, radio temperature sensor chip low in energy consumption, mainly include Power Management Unit, temperature sensor unit, band-gap reference list
The part such as unit, ADC unit, live detection unit, Transmit Receive Unit, Power Management Unit support includes CT energy taking device, electricity
The multiple front end self-energizing installation's power source inputs such as field coupling energy taking device, also support the input of external power supply;The side of collecting temperature
Formula had both supported the temperature sensor unit that chip internal is integrated, also supported the mode of outside cut-in temperature sensor.
I.e. can be used for environment under high pressure in order to ensure chip and can also apply to lower pressure environment, spy based on energy taking device of the present invention
Point, and the feature of power equipment applied environment, as in figure 2 it is shown, Power Management Unit realizes based on LDO structure, and consider
Higher voltage may be exported to energy taking device, therefore use in technique and can design by high voltage bearing LDMOS pipe.
The present embodiment provides the circuit theory diagrams of a kind of Power Management Unit, as in figure 2 it is shown, whole LDO circuit will
The high pressure HV_IN of energy taking device output, as power supply, produces band-gap reference by simple biasing circuit (two, the left side)
The auxiliary moding circuit of unit, audion Q1 and audion Q2, as scale tube, produce △ VBE(emitter stage is relative to the electricity of base stage
Pressure), current mirror M1 and M2 ensure that two branch currents are equal, bandgap voltage reference A point produce after, by resistance R3 with
The boosting of R4 ratio reaches VB, deduct V the most againGS5(in metal-oxide-semiconductor M5, grid is relative to the voltage of source electrode) thus obtain AVDD.Its
In, metal-oxide-semiconductor M4, M5, M6, M7, M8 and audion Q2, Q3 collectively constitute a simple feedback circuit, it is achieved AVDD from
Dynamic regulation, i.e. when AVDD voltage is pulled low, metal-oxide-semiconductor M5 electric current increases, and by the feedback of current mirror, B point voltage is pulled down, this
Time at the V of metal-oxide-semiconductor M4GSCan rise, thus B electrical voltage point is pulled up, and then AVDD is raised, complete feedback, by this circuit
Design, when AVDD does not drives load, the power consumption of LDO circuit is extremely low, about 30uA.
Temperature sensor unit is an integrated semiconductor device temperature sensor circuit, around detection chip
Ambient temperature, and the overheat protector signal of whole chip produces also based on this circuit, in the present invention, the mode of collecting temperature
Both supported the temperature sensor unit that chip internal is integrated, also supported that the mode of outside cut-in temperature sensor was (as platinum resistance passes
Sensor etc.), thus temperature sensor unit can be integrated in chip exterior, also can be integrated in chip internal.
The present embodiment provides the circuit theory diagrams of a kind of temperature sensor unit, as it is shown on figure 3, in the dotted line frame of the left side
Circuit produce a PTAT current IPTAT, the size of this electric current and resistance R12 and four audions Q12, Q22, Q32, Q42's
Launch site area ratio is relevant, and the current mirror that this electric current forms through P1 and P3 produces temperature voltage signal;In this circuit the rightest
Edge is divided into thermal-shutdown circuit, and after normal circuit operation, A, B point voltage is high voltage, and C point voltage is low-voltage, now A point
Voltage VA=IPTAT* R32, along with the rising of temperature, A point voltage also raises, and when reaching certain temperature, A point voltage reaches three poles
The threshold voltage of pipe Q52, the audion Q52 conducting when exceeding this temperature, after its conducting, B point voltage becomes low-voltage, now
A point voltage becomes VA=IPTAT* (R32+R42), therefore B point signal can be used as the overheat protector indication signal of full chip.
The function of bandgap reference cell is to enable the chip to reliably working within the temperature range of requiring, at whole temperature model
Interior offer is provided and stablizes constant DC reference voltage, provide reference voltage for AD conversion unit, and be other unit of full chip
Reliable voltage or current offset are provided, thus are greatly enhanced the temperature reliability of whole chip, according to practical situation, voltage
Temperature coefficient can be less than 10ppm/ DEG C.
Providing the circuit theory diagrams of a kind of bandgap reference cell in the present embodiment, as shown in Figure 4, reference circuit is by three poles
The ratioed transistor that pipe Q13 and Q23 is formed produces, and then the signal feeding of generation is made up of resistance R43, R53, R63
Divider resistance string, produces required reference voltage VREF, wherein, resistance R53 and R7a, R7b are to carry out TRIMThe adjustable electric of regulation
Resistance (such as slide rheostat), is used for improving resistance precision, and audion Q43, Q53 and P4, P5(P can use metal-oxide-semiconductor, computing to put
The devices such as big device, if can realize corresponding function just can) generate the voltage needed for audion Q33, be also introduced into negative feedback simultaneously, come
Improving loop stability, adjustable resistance R53 is mainly used to produce dividing potential drop, produces required reference voltage V with accurateREF, P6 and fortune
Calculate amplifier T together on the basis of voltage VREFNecessary driving force is provided, produces feedback control loop by operational amplifier T simultaneously, come
Reduce owing to load change is to VREFImpact.
In order to improve chip performance, reduce power consumption, the ADC unit in the present invention uses successive approximation structure, in order to reality
The AD conversion of existing temperature signal, relative to the ADC unit of other form, uses successive approximation structure to have simple in construction, low
Cost, the clear superiority of low-power consumption.The ADC unit of this kind of structure can include 16 ratio electric capacity, a series of control switch with
And a comparator, under the control of logic circuit, the analog temperature signal that sampling is obtained by it is gradually carried out with reference signal
Relatively, draw each digital conversion results, owing to the control of circuit is mainly completed by digital circuit, therefore there is extremely low merit
Consumption.
Whether live detection unit is in normal output state by current induction energy fetching device judges monitored equipment
The most charged, band electrical information can be exported simultaneously, thus auxiliary realizes equipment HV live displaying and blocking function.
Transmit Receive Unit includes GFSK radio-frequency transmitter, GFSK radio frequency sending set, by digital base band processor module and MAC
The processing unit that layer processing module is constituted, i.e. radio frequency transceiver include launching and receiving two large divisions, and can be by a sheet
Transmit-receive switch realizes launching and receiving the multiplexing in time domain.In order to reduce power consumption and the cost of chip, whole reception passage can be adopted
By the heterodyne architecture of Low Medium Frequency, low intermediate frequency structure is used only to need single-conversion, simple in construction, cost and zero intermediate frequency formula receiver
Quite, but can effectively solve the problem that local-oscillator leakage in zero intermediate frequency reciver, even nonlinearity, direct current offset, flicker noise and be subject to
The big problem such as I/Q mismatch impact, can include low-noise amplifier, down-conversion mixer, plural number bandpass filtering in receiver path
Device, amplitude limiter and an ADC etc. realizing receiving intensity indication signal AD conversion, owing to the transceiver of this kind of structure belongs to existing
Mature technology in technology, thus more explanation is not made at this.
In the present invention, different from the transmitter of other conventional modulated pattern, the transmitter in the present invention does not has up-conversion to mix
Frequently device, but realize based on a decimal N-type frequency synthesizer, and baseband circuit digital circuit and MAC protocol processing module
Circuit all uses digital circuit hardware to realize, and the receiving portion of baseband circuit is in order to realize further channel filtering, GFSK
Demodulation, automatic growth control (AGC), frame synchronization;It is inclined that emitting portion realizes launching power control, Channel assignment and GFSK frequency
Move the functions such as control.
In order to realize above-mentioned functions, giving the circuit structure diagram of a kind of Transmit Receive Unit in the present embodiment, GFSK penetrates
Frequency receiver include the low-noise amplifier being sequentially connected, down-conversion mixer, complex bandpass filters, by N level logarithmic amplification
The amplitude limiter of device composition and an ADC transducer realizing receiving intensity indication signal AD conversion.Wherein, low-noise amplifier will
Radiofrequency signal is amplified restraining the noise of late-class circuit, and frequency mixer realizes the quadrature frequency conversion of radiofrequency signal, is become by signal
Frequency is to the intermediate frequency of 2MHz, and complex bandpass filters carries out Channel assignment and image frequency suppression, thus avoids using the intermediate frequency filter of off-chip
Ripple device, complex filter preferably employs activated amplifier structure, it is provided that certain adjustable gain, and filtered intermediate-freuqncy signal is passed through
Amplitude limiter enters base-band digital circuit after carrying out limited range enlargement.Wherein, amplitude limiter circuit is equivalent to the ADC of 1 bit and turns
Parallel operation, can be with receiving intensity indication signal by its special logafier cascade structure, to assist base-band digital circuit real
Existing automatic growth control, and judge that channel is the most idle.In order to realize automatic growth control, the low noise amplification in the present invention
The gain of device and active band-pass filter all can be configured by base-band digital circuit, in order to reduce the work frequency of baseband circuit
Rate, the mid frequency of intermediate-freuqncy signal can be identified as 1MHz, uses lower sideband injection mode, namely makes local oscillation signal be less than radio frequency
Carrier signal, such as radiofrequency signal are 472MHz, then local oscillation signal is 470MHz, and the local oscillation signal frequency of each channel is with this type of
Push away.
GFSK radio frequency sending set does not has up-conversion mixer, but realizes based on a decimal N-type frequency synthesizer,
Under emission mode, the digital information of digital baseband circuit output is modulated through GFSK, then carries out the gaussian filtering sum tone of Chinese characters respectively
System so that whole decimal frequency divider output through GFSK control radiofrequency signal, this signal again after power amplification, from
Antenna is launched.GFSK signal is constant envelope signal, so the power amplifier in the present invention preferably employs high efficiency E class
Amplifier realizes, and to reduce the power consumption of power amplifier, and can realize on the sheet of power amplifier integrated.Sending out of power amplifier
Penetrate power to be controlled by base-band digital circuit and configure, generally, the V in frequency synthesizerCOOperating frequency is for carrying
The twice of wave frequency, after high speed Orthogonal two divided-frequency, outgoing carrier frequency, and provide the basis needed for down coversion for receiver
Shake signal.
According to above-described embodiment, the present invention just can be realized well.