CN208297671U - A kind of digital power circuit based on MEMS sensor - Google Patents

Abstract

A kind of digital power circuit based on MEMS sensor solves in the high prior art its current source power consumption, stability difference and prior art loop oscillator that there are a large amount of impulsive noises and the technical problems such as versatility is low the utility model relates to circuit testing technology field.The utility model includes high-precision oscillation circuit；More current mirroring circuits export the electric current with fixed bias；Pulse generation circuit exports alternating current pulse；Frequency match circuit is buffered, the alternating current pulse of pulse generation circuit output is received；Benchmark MEMS sensor exports the feedback reference clock with its timing loop performance characteristic；Further include the first MEMS sensor to be measured, receives the first squared pulse trains and output has the first feedback clock of its timing loop performance characteristic；Second MEMS sensor to be measured, receives the second squared pulse trains and output has the second feedback clock of its timing loop performance characteristic.

Description

A kind of digital power circuit based on MEMS sensor

Technical field

The utility model relates to circuit testing technology fields, and in particular to a kind of digital power electricity based on MEMS sensor Road.

Background technique

Sequence circuit pulse to be treated is the alternating current pulse of Larger Dynamic range.Mainstream test method is directly to connect Enter MEMS power supply, is tested.But current mainstream test equipment is not equipped with high speed alternator driven current mode clock, thus into When the sampling observation test of row MEMS sensor volume production, it is difficult to carry out AC signal test.Therefore some manufacturers abandon alternating-current measurement, DC test is only carried out in volume production test process, is not tested sufficiently so as to cause chip matching capacity and tolerance, is tested Coverage rate substantially reduces.Some manufacturers buy the special test clock of customization, but due to customization to guarantee test coverage The higher cost of test equipment, so as to cause the testing cost for substantially increasing chip.

Although electromagnetic noise does signal generator currently, existing signal generator is quite mature It disturbs and always exists, directly affect the long-time stability and reliability of product.On the other hand, in digital circuit, analog sensor, essence Close instrument and meter etc., the requirement to output waveform in signal generator are higher and higher.Traditional circuit, form are more multiple It is miscellaneous, using more WeChat ID device, it is easy the interference by adverse circumstances, is used for a long time there are certain hidden danger, for a long time may be used It can not be guaranteed by property.The stability and frequency characteristic of prior art square-wave generator are all to be improved.

Utility model content

For the above-mentioned prior art, the utility model aim is to provide, and the solution prior art cannot detect multiple simultaneously MEMS sensor, its current source power consumption are high and stability is poor, and there are a large amount of impulsive noises and logical in prior art loop oscillator With the technical problems such as property is low.

In order to achieve the above objectives, the technical solution adopted in the utility model is as follows:

A kind of digital power circuit based on MEMS sensor, comprising:

High-precision oscillation circuit, output triangular pulse have the first squared pulse trains of relative phase difference and second Squared pulse trains, including the output road for being made of three respective pulses field effect transistor circuitry and inverter circuit Diameter；

More current mirroring circuits export the electric current with fixed bias；

Pulse generation circuit, two input terminal are connected respectively to the high-precision oscillation circuit and more current mirrors Triangular pulse TCLK and the electric current and output alternating current arteries and veins described in the output end of circuit, its output clock pulse modulation Punching；

Frequency match circuit is buffered, the alternating current pulse of pulse generation circuit output is received；

Benchmark MEMS sensor, the related alternating current pulse and corresponding correlation for receiving buffering frequency match circuit output are handed over Time-dependent current pulse output has the feedback reference clock of its timing loop performance characteristic；

Further include

First MEMS sensor to be measured, receives the first squared pulse trains and output has its timing loop performance characteristic First feedback clock；

Second MEMS sensor to be measured, receives the second squared pulse trains and output has its timing loop performance characteristic Second feedback clock；

Wherein, the feedback reference clock, by obtaining the first clock difference compared with the first feedback clock and with the It is poor that two feedback clocks compare acquisition second clock；

Wherein, first clock difference and second clock are poor, compared with experience clock difference, meet opposite experience clock difference The first MEMS sensor to be measured or the second MEMS sensor to be measured deviateed within variation ± 5% is qualified product.

In above scheme, the pulse generation circuit includes the first NMOS tube, and drain electrode is connected to more current mirrors The output end of circuit, grid are connected to the output end of the high-precision oscillation circuit, and source electrode is connected to the pulse and produces The output end of raw circuit.

In above scheme, the source electrode of first NMOS tube is connected to the pulse generation circuit by first resistor Output end.

In above scheme, the pulse generation circuit further includes the second NMOS tube, and grid is connected to by phase inverter The output end of the high-precision oscillation circuit, drain electrode are connected to the output end of more current mirroring circuits, and source electrode passes through string Join the second resistance of connection and the third NMOS tube ground connection of diode connecting-type.

In above scheme, the high-precision oscillation circuit, including

For providing the current source circuit of loop charge and discharge, the inverter circuit for switching loop output and for providing The buffer circuit of phase difference, current source circuit and inverter circuit constitute loop oscillation structure.

In above scheme, the impulse generating unit further includes overshoot protection circuit, receives the output of inverter circuit Clock, and the selectively input power of leakage current source circuit.

In above scheme, the current source circuit, including

First power supply；

First current source, high potential end connect the first power supply；

First field-effect tube, source electrode connect the low potential end of the first current source；

Second field-effect tube, source electrode connect the low potential end of the first current source and grounded drain；

Third field-effect tube, the drain electrode of drain electrode the first field-effect tube of connection；

4th field-effect tube, source electrode connect the source electrode of third field-effect tube；

Second source connects the drain electrode of the 4th field-effect tube；

Second current source, high potential end connects the source electrode of third field-effect tube and low potential end is grounded；

First capacitor is used for charge and discharge charge buffer, and one end connects the first power supply and the other end connects the first field-effect The drain electrode of pipe.

In above scheme, the inverter circuit is used to form interior ring oscillation and the switching output of reflexive feedthrough voltage, including

5th field-effect tube, grid connect the drain electrode of the first field-effect tube；

6th field-effect tube, grid connect the leakage of the drain electrode of the first field-effect tube and drain electrode the 5th field-effect tube of connection Pole；

7th field-effect tube, grid, drain electrode are all connected with the source electrode of the 6th field-effect tube and source electrode is grounded；

8th field-effect tube, for being switched as bias voltage, the source electrode and source electrode of drain electrode the 6th field-effect tube of connection Ground connection；

Third power supply；

9th field-effect tube, grid, drain electrode are all connected with the source electrode of the 5th field-effect tube and source electrode connection third power supply；

Tenth field-effect tube, for switching as bias voltage, source electrode connects third power supply and drain electrode connection the 5th The source electrode of effect pipe；

First phase inverter, input terminal connect the drain electrode of the 5th field-effect tube；

Second phase inverter, third phase inverter and the second capacitor, are sequentially connected in series the first phase inverter, and the second capacitor is additionally coupled to The grid of five feedback loops constitutes the feedback loop of inverter circuit；

Third capacitor, for provide inner ring oscillation circuit charging, electric discharge, one end connect the first field-effect tube drain electrode and Other end ground connection；

Tenth field-effect tube, the 8th field-effect tube, grid are connected to the output end of third phase inverter, for defeated Switch out；

Second field-effect tube, the 4th field-effect tube, grid is connected to the output end of the second phase inverter, for filling Electric discharge switching.

In above scheme, the buffer circuit is exported for obtaining two-way delay, including

4th phase inverter, input terminal connect the output end of the second phase inverter；

5th phase inverter, hex inverter constitute latch, the 4th phase inverter of series of latches；

7th phase inverter, input terminal connect latch outputs；

First buffer, the 7th phase inverter of connecting, exports the first squared pulse trains；

Second buffer, the 4th phase inverter of connecting, exports the second squared pulse trains；

First field-effect tube, third field-effect tube, grid is connected to the output end of the 4th phase inverter, for filling Electric discharge switching；

The first capacitor, voltage change end are connected with divider resistance, and divider resistance exports triangular pulse.

In above scheme, the overshoot protection circuit, power supply is quickly released when for crossing oscillation, including

Comparator, high electricity end is connected with reference voltage and low electric end connects the grid of the 5th field-effect tube；

NAND gate, input port connect the output end of comparator and receive an enabling pulse；

11st field-effect tube, grid connect NAND gate output end, drain electrode connection the first field-effect tube drain electrode and Source electrode ground connection.

In above scheme, the third field-effect tube, source electrode is also connected with the 4th capacitor, and the 4th capacitor is also grounded.

Compared with prior art, the utility model has the beneficial effects that low in energy consumption and offer frequency matching；Improve its pulse The stability of generator realizes more smooth loop oscillation charge and discharge process under the premise of not influencing output characteristics.

Detailed description of the invention

Fig. 1 is the module diagram of the utility model；

Fig. 2 is the utility model high-precision oscillation circuit schematic illustration；

Fig. 3 is the utility model high-precision oscillation circuit inner part potential point voltage change schematic diagram；

Fig. 4 is the circuit diagram of the first current source of the utility model.

Specific embodiment

All features disclosed in this specification or disclosed all methods or in the process the step of, in addition to mutually exclusive Feature and/or step other than, can combine in any way.

The utility model is described further with reference to the accompanying drawing:

Embodiment 1

Output triangular pulse TCLK, high-precision oscillation circuit has the first squared pulse trains of relative phase difference PCLK1 and the second squared pulse trains PCLK2 is right including being made of three field effect transistor circuitry and inverter circuit Answer the outgoing route of pulse；

More current mirroring circuits export the electric current with fixed bias；

Pulse generation circuit, two input terminal are connected respectively to the high-precision oscillation circuit and more current mirrors Triangular pulse TCLK and the electric current and output alternating current arteries and veins described in the output end of circuit, its output clock pulse modulation Punching；

Frequency match circuit is buffered, the alternating current pulse of pulse generation circuit output is received；

Benchmark MEMS sensor, the related alternating current pulse and corresponding correlation for receiving buffering frequency match circuit output are handed over Time-dependent current pulse output has the feedback reference clock of its timing loop performance characteristicBK；

Further include

First MEMS sensor to be measured, receives the first squared pulse trains PCLK1 and output has its timing loop performance First feedback clock of featureTK1；

Second MEMS sensor to be measured, receives the second squared pulse trains PCLK2 and output has its timing loop performance Second feedback clock of featureTK2；

Wherein, pass through feedback reference clockBKWith the first feedback clockTK1Clock differenceΔK1And feedback reference clock With the second feedback clockTK2Clock differenceΔK2, with experience clock differenceΔKCompare, meets opposite experience clock differenceΔKDeviate and becomes Changing the MEMS sensor within ± 5% is qualified product.

The utility model further includes level suppression circuit comprising first node, the first node pass through the 4th PMOS Pipe is connected to accessory power supply and is grounded by the 5th NMOS tube, and the grid of the 4th PMOS tube and the 5th NMOS tube is all connected with To accessory power supply, wherein the first node is connected with the enable end of the high-precision oscillation circuit.More current mirror electricity Road includes the 6th and the 7th PMOS tube being connected in series, and the source electrode of the 6th PMOS tube is connected to accessory power supply, and the described 7th The drain electrode of PMOS tube is connected to the output end of more current mirroring circuits, and the grid of the 6th and the 7th PMOS tube is separately connected First and second bias voltages, first bias voltage are greater than second bias voltage.

For higher versatility and low cost, the utility model uses two buffer registers and a programmable delay Device constitutes frequency and matches ring, and as buffering frequency match circuit, two buffer register input terminals receive pulse and generate electricity The alternating current pulse of road output, the input terminal of the output end connection programmable delayer of one of buffer register are related Alternating current pulse is collectively formed by the output pulse of programmable delayer and the output pulse of another buffer register.

The high-precision oscillation circuit, in conjunction with Fig. 2 and Fig. 3, field-effect tube Q8, Q12 is equivalent to diode, field-effect tube Q9, Q13 as feedback control bias voltage switch, field-effect tube Q10, Q11 constitute by field-effect tube Q9, Q13 control etc. Phase inverter is imitated, the output clock waveform of inverter circuit is clock waveform at potential point C, and the input power of current source circuit includes Current source I1 and current source I2；Reference clock SCLK can be inputted at potential point A, can also be with defeated at scene effect pipe Q5 grid Enter, it is ground voltage that circuit primary condition, which is set as potential point A, and field-effect tube Q5, Q10, Q9 are in the conductive state, current source I1 It charges to capacitor C1, is sufficient to make field-effect tube Q10 to end when capacitor C1 voltage is raised to, equivalent phase inverter deflects, current potential Point D voltage becomes ground voltage from voltage VCC, and field-effect tube Q9 ends and field-effect tube Q13 is connected, field-effect tube Q4 conducting, Current source I1 is released, and current source I2 discharges to capacitor C1, until field-effect tube Q10 is switched on again, constantly repeats this One process, and then export oscillation square wave.Due to using capacitor and current source in impulse generator, the complete of actual use device is considered U.S. degree, charge and discharge lead to may have higher peak voltage value in circuit there may be the window of overlapping, and most probably send out It is raw to be detected at potential point C so comparator is arranged, for discharging in time peak voltage, can also further be arranged NAND gate logic circuit is driven using the enable signal of processing chip.

As Fig. 4, the first current source I1 include resistance 101, NMOS tube 102, NMOS tube 103, NMOS tube 104, NMOS tube 105, PMOS tube 106, PMOS tube 107 and PMOS tube 108: one end of the resistance 101 is grounded, described in another termination The source electrode of NMOS tube 102；The grid of the NMOS tube 102 connects the grid of the NMOS tube 103 and drains and the NMOS tube 105 Source electrode, drain electrode connects the source electrode of the NMOS tube 104, and source electrode connects one end of the resistance 101；The grid of the NMOS tube 103 It is connected together with drain electrode and connects the source electrode of the NMOS tube 105 and the grid of the NMOS tube 102 again, source electrode ground connection；The NMOS The grid of pipe 104 connects the drain electrode of the PMOS tube 106 and grid and the drain electrode of the NMOS tube 105, and drain electrode connects the PMOS tube The grid of 106 grid and the grid of the PMOS tube 107 and drain electrode and the PMOS tube 108, source electrode connect the NMOS tube 102 Drain electrode；The grid of the NMOS tube 105 and drain electrode are connected together connects the drain electrode and the NMOS tube of the PMOS tube 106 again 104 grid, source electrode connect the grid of the NMOS tube 103 and the grid of drain electrode and the NMOS tube 102；The PMOS tube 106 Grid connect the PMOS tube 107 grid and drain electrode and the grid of the PMOS tube 108 and the drain electrode of the NMOS tube 104, Drain electrode connects the grid of the NMOS tube 105 and the grid of drain electrode and the NMOS tube 104, and source electrode meets supply voltage VCC；It is described The grid of PMOS tube 107 and drain electrode are connected together meets the grid of the PMOS tube 106 and the grid of the PMOS tube 108 and institute again The drain electrode of NMOS tube 104 is stated, source electrode meets supply voltage VCC；The grid of the PMOS tube 108 connects the grid of the PMOS tube 106 With the grid of the PMOS tube 107 and the drain electrode of drain electrode and the NMOS tube 104, drain electrode is used as current output terminal IOUT, source electrode Meet supply voltage VCC.

The voltage at 101 both ends of resistance is the threshold voltage of the NMOS tube 103, and the electric current on the resistance 101 is For the threshold voltage of the NMOS tube 103 divided by the resistance value of the resistance 101, which passes through 107 mirror image of PMOS tube again To the PMOS tube 106 and the PMOS tube 108, from the drain electrode output current IO UT of the PMOS tube 108.

Above description is only a specific implementation of the present invention, but the protection scope of the utility model is not limited to It is any to belong to those skilled in the art within the technical scope disclosed by the utility model in this, the change that can be readily occurred in Change or replace, should be covered within the scope of the utility model.

Claims (1)

1. a kind of digital power circuit based on MEMS sensor characterized by comprising

High-precision oscillation circuit, output triangular pulse TCLK, have relative phase difference the first squared pulse trains PCLK1 and Second squared pulse trains PCLK2, including being made of three respective pulses field effect transistor circuitry and inverter circuit Outgoing route；

More current mirroring circuits export the electric current with fixed bias；

Pulse generation circuit, two input terminal are connected respectively to the high-precision oscillation circuit and more current mirroring circuits Output end, its export clock pulse modulation described in triangular pulse TCLK and the electric current and output alternating current pulse；

Frequency match circuit is buffered, the alternating current pulse of pulse generation circuit output is received；

Benchmark MEMS sensor receives the related alternating current pulse of buffering frequency match circuit output and corresponding related alternation electricity Flow the feedback reference clock that pulse output has its timing loop performance characteristic；

Further include

First MEMS sensor to be measured, receives the first squared pulse trains PCLK1 and output has its timing loop performance characteristic The first feedback clock；

Second MEMS sensor to be measured, receives the second squared pulse trains PCLK2 and output has its timing loop performance characteristic The second feedback clock；

The feedback reference clock, by compared with the first feedback clock obtain the first clock difference and with the second feedback clock It is poor to compare acquisition second clock；

The pulse generation circuit includes the first NMOS tube, and drain electrode is connected to the output end of more current mirroring circuits, Grid is connected to the output end of the high-precision oscillation circuit, and source electrode is connected to the output end of the pulse generation circuit.