CN208334480U - A kind of small signal high precision peak detection device of high bandwidth - Google Patents

Abstract

The utility model discloses a kind of small signal high precision peak detection devices of high bandwidth, wherein, including voltage-reference, comparison circuit, frequency down circuit, control circuit and display circuit, the control circuit connects voltage-reference, the negative input end of the voltage-reference connection comparison circuit, the one detection signal of positive input terminal connection of the comparison circuit, the comparison circuit pass sequentially through frequency down circuit, control circuit and display circuit and connect.A kind of small signal high precision peak detection device of high bandwidth of the utility model has the characteristics that accuracy of data acquisition height, with wide, speed is fast, low in cost.

Description

A kind of small signal high precision peak detection device of high bandwidth

Technical field

The utility model relates to detection device fields, more specifically more particularly to a kind of small signal high precision of high bandwidth Peak detection device.

Background technique

In the electronic device, it is often required to measure the peak value of signal, the detection scheme generally used is to use diode Detection is carried out with capacitor, this wave detector poor effect is mainly manifested in: if the time constant of the RC circuit of selection is big by one A bit, then the waveform of the rectified signal exported will be better, but the rectified signal exported is due to being influenced width by diode Degree can be substantially reduced, and if especially working as signal of the inputted signal less than diode conduction voltage drop, just be had no idea at all The peak detection of signal is come out, operational amplifier can be added in the signal demodulator of middle low frequency signal to construct progress frequency reducing Circuit, but for high-frequency signal, after 100MHz, suitable operational amplifier is seldom and price is high Expensive, frequency down circuit cost is too high.Therefore, how to realize the small signal high precision peak detection of high bandwidth, reduce detector arrangement cost Become peak detection device problem urgently to be resolved in electronic equipment.

Utility model content

The purpose of this utility model is to provide a kind of small signal high precision peak detection device of high bandwidth, the detector arrangements Has the characteristics that accuracy of data acquisition height, with wide, speed is fast, low in cost.

The technical solution adopted in the utility model is as follows:

A kind of small signal high precision peak detection device of high bandwidth, wherein including voltage-reference, comparison circuit, frequency reducing Circuit, control circuit and display circuit, the control circuit connect voltage-reference, and the voltage-reference connects ratio Compared with the negative input end of circuit, the one detection signal of positive input terminal connection of the comparison circuit, the comparison circuit is passed sequentially through Frequency down circuit, control circuit and display circuit connect.

Preferably, the comparison circuit includes comparator, electric source filter circuit and first resistor R3, R4, and described first One end of resistance R3, R4 are separately connected the positive input terminal of comparator simultaneously and detection signal, the other end are grounded simultaneously, the electricity Power filter includes third capacitor C3 and the 4th capacitor C4, and one end of the third capacitor C3 and the 4th capacitor C4 connect simultaneously Connect the positive voltage terminal and power supply of comparator, the other end ground connection of the third capacitor C3, another termination of the 4th capacitor C4 Ground.

Preferably, the frequency down circuit includes first diode D1, the 6th capacitor C6, the 7th resistance C7, the comparison The output end of device passes through the 6th capacitor C6, the 7th resistance C7 and control circuit connection respectively after first diode D1, and described the The other end of six capacitor C6 and the other end of the 7th resistance C7 are grounded respectively.

Preferably, the control circuit includes STM8 chip, SWIM interface, the 7th capacitor C7, the 8th capacitor C8 and Eight resistance R8, the 4th pin of the STM8 chip are connect with the 8th capacitor C8 and the 8th resistance R8 respectively, the 8th capacitor The other end of C8 is grounded, and the other end of the 8th resistance R8 connects external power supply, and the 7th pin of the STM8 chip is grounded, 8th pin of the STM8 chip is grounded by the 7th capacitor C7, and the 1st pin of the STM8 chip connects voltage-reference, 1st pin of the SWIM interface connects external power supply, and the 18th of the 2nd pin connection STM8 chip of the SWIM interface is drawn Foot, the 3rd pin ground connection of the SWIM interface, the 4th pin of the 4th pin connection STM8 chip of the SWIM interface.

Preferably, the voltage-reference include the 6th resistance R6 and the 5th capacitor C5, the first of the STM8 chip The negative input end and the 5th capacitor C5 of comparison circuit are separately connected after the 6th resistance R6 of pin connection, the 5th capacitor C5's Other end ground connection.

Preferably, the display circuit includes resistance group and charactron, and the resistance group includes eight in parallel identical First resistor R91, second resistance R92,3rd resistor R93, the 4th resistance R94, the 5th resistance R95, the 6th resistance R96, Seven resistance R97 and the 8th resistance R98, the 13rd pin of the STM8 chip pass through the 3rd of first resistor R91 connection charactron the Pin, the 14th pin of the STM8 chip pass through the 5th pin of second resistance R92 connection charactron, the STM8 chip 15th pin passes through the 10th pin of 3rd resistor R93 connection charactron, and the 16th pin of the STM8 chip passes through the 4th electricity The 1st pin of R94 connection charactron is hindered, the 17th pin of the STM8 chip passes through the 2nd of the 5th resistance R95 connection charactron the Pin, the 18th pin of the STM8 chip pass through the 4th pin of the 6th resistance R96 connection charactron, the STM8 chip 19th pin passes through the 7th pin of the 7th resistance R97 connection charactron, and the 20th pin of the STM8 chip passes through the 8th resistance 11st pin of R98 connection charactron, the 6th pin of the 3rd pin connection charactron of the STM8 chip, the STM8 core 8th pin of the 10th pin connection charactron of piece, the 9th pin of the 11st pin connection charactron of the STM8 chip, institute State the 12nd pin of the 12nd pin connection charactron of STM8 chip.

Compared with prior art, the utility model has the beneficial effect that

The small signal high precision peak detection device of a kind of high bandwidth of the utility model, wherein including voltage-reference, ratio Compared with circuit, frequency down circuit, control circuit and display circuit, the control circuit connects voltage-reference, the voltage A reference source connects the negative input end of comparison circuit, the one detection signal of positive input terminal connection of the comparison circuit, the comparison Circuit passes sequentially through frequency down circuit, control circuit and display circuit and connects.Benchmark is provided using control circuit for voltage-reference Voltage, when the voltage for detecting signal is bigger than voltage-reference offer voltage, comparison circuit exports high level, anyway export low electricity Flat, to will test signal shaping, the detection signal after shaping is converted to low frequency signal by frequency down circuit, and control circuit is by low frequency Signal is identified, finally shows that the detection signal of high frequency is converted to low by signal peak, this detector arrangement in display circuit Control circuit identification is recycled after frequency, and the power supply of voltage-reference is adjusted enough to accurate using control circuit, ties detection The precision of structure is higher, and a kind of small signal high precision peak detection device of high bandwidth of the utility model is capable of detecting when that frequency is 0- The random waveform of 120MHz, detection bandwidth is wider, and faster, structure is simple, and cost is lower for detection speed.

Detailed description of the invention

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

Fig. 2 is the circuit diagram of voltage-reference in the utility model, comparison circuit and frequency down circuit；

Fig. 3 is the circuit diagram of control circuit and display circuit in the utility model；

Fig. 4 is the circuit diagram of voltage-reference in the utility model；

Fig. 5 is the PWM waveform that STM8 chip exports in the utility model；

Fig. 6 is the DAC waveform that the output waveform of Fig. 5 exports after voltage-reference.

Specific embodiment

With reference to embodiment, the technical solution of the utility model is described in further detail, but not structure Any restrictions of pairs of the utility model.

Shown in 4, a kind of small signal high precision peak detection device of high bandwidth of the utility model, wherein packet Voltage-reference 1, comparison circuit 2, frequency down circuit 3, control circuit 4 and display circuit 5 are included, the control circuit 4 connects Voltage-reference 1, the voltage-reference 1 connect the negative input end of comparison circuit 2, the positive input terminal of the comparison circuit 2 One detection signal of connection, the comparison circuit 2 passes sequentially through frequency down circuit 3, control circuit 4 is connect with display circuit 5.It utilizes Control circuit 4 is that voltage-reference 1 provides reference voltage, when the voltage for detecting signal is bigger than the offer voltage of voltage-reference 1, Comparison circuit 2 exports high level, and when the voltage for detecting signal is smaller than the offer voltage of voltage-reference 1, comparison circuit 2 exports low Level, the realization of comparison circuit 2 will test signal shaping, and the detection signal after shaping is converted to low frequency signal by frequency down circuit 3, control Circuit 4 processed identifies low frequency signal, finally shows signal peak in display circuit 5, this detector arrangement is by the inspection of high frequency Surveying after signal is converted to low frequency recycles control circuit 4 to identify, is adjusted the power supply of voltage-reference 1 using control circuit 4 Enough precisely, keep the precision of detection structure higher, a kind of small signal high precision peak detection device of high bandwidth of the utility model The voltage for allowing input signal is 0-5V, and frequency is the random waveform of 0-120MHz, and detection bandwidth is wider, detects speed faster, Structure is simple, and cost is lower.

The comparison circuit 2 includes comparator 21, electric source filter circuit 22, first resistor R3 and first resistor R4, institute It states one end of first resistor R3 and first resistor R4 while being separately connected the positive input terminal and detection signal of comparator 21, the other end It is grounded simultaneously, the resistance value of first resistor R3 and first resistor R4 are 100 ohm, and therefore, the resistance of 21 positive input terminal of comparator is 50 ohm.The electric source filter circuit 22 includes third capacitor C3 and the 4th capacitor C4, the electricity of the third capacitor C3 and the 4th The one end for holding C4 connects the positive voltage terminal and power supply of comparator 21 simultaneously, the other end ground connection of the third capacitor C3, and described the The other end of four capacitor C4 is grounded.Comparator 21 is preferably using the high-speed comparator of TI company production in this detector arrangement TLV3501, TLV3501 are single channel high speed push-pull output comparators, delay time 4.5ns, supply voltage be+2.7V to+ 5.5V, have makes it be very suitable to the ideal chose of low voltage application beyond amplitude of oscillation input common-mode range.Track to track output can be with CMOS or TTL logic is directly driven, shaping can be carried out to wide-voltage range periodic signal, be as ideal frequency, phase The front end conditioning module of the times domain measurement such as difference.

The frequency down circuit 3 includes first diode D1, the 6th capacitor C6, the 7th resistance C7, the comparator 21 Output end is connect with the 6th capacitor C6, the 7th resistance C7 and control circuit 4 respectively after passing through first diode D1, and the described 6th The other end of capacitor C6 and the 7th resistance C7 are grounded, at the high-frequency signal that frequency down circuit 3 can export 2 output end of comparison circuit Low frequency signal is managed into, control circuit 4 is enable to identify.

The control circuit 4 includes STM8 chip 41, SWIM interface 42, the 7th capacitor C7, the 8th capacitor C8 and the 8th Resistance R8, the 4th pin of the STM8 chip 41 are connect with the 8th capacitor C8 and the 8th resistance R8 respectively, the 8th capacitor C8 Other end ground connection, the other end of the 8th resistance R8 connects external power supply.Electrification reset built in STM8 chip 41, so STM8 chip 41 can not set external electrification reset circuit, still can be with normal reset and steady operation.If system needs are set Key reset circuit is set, then note that STM8 chip 41 is that low level resets, therefore, using the 8th resistance R8 and the 8th capacitor C8 forms reset circuit, also avoids system when operation, due to NRST pin floating, is caused by the interference of external pulse circuit Baffled reset.

7th pin of the STM8 chip 41 is grounded, and the 8th pin of the STM8 chip 41 is connect by the 7th capacitor C7 Ground, the 1st pin of the STM8 chip 41 connect voltage-reference 1, and the 1st pin of the SWIM interface 42 connects external electrical Source, the 18th pin of the 2nd pin connection STM8 chip 41 of the SWIM interface 42, the 3rd pin of the SWIM interface 42 connect Ground, the 4th pin of the 4th pin connection STM8 chip 41 of the SWIM interface 42.STM8 chip 41 is the STM8 system of ST company The STM8S103F3P6 single-chip microcontroller of column, Rubis Class Nuclear Attack Submarine.STM8 chip 41 supports SWIM debud mode, STM8S103F3 There are 640 bytes, and can be with erasable 10,000 times.16 bit timings/counter is equipped with inside STM8 chip 41,16 GPIO pins are complete It meets entirely and uses needs.Since the GPIO pin driving capability of STM8 chip 41 is stronger, in addition the detection of the utility model Charactron 52 of the device for display uses Dynamically Announce, so the resistance group 51 of current limliting is directly used for GPIO pin series connection Scheme drive digital tube 52,8 pins in STM8 chip 41 are connected respectively to the Duan Xuan of charactron 52, i.e., in charactron 52 A, the corresponding pin of b, c, d, e, f, g, eight pins of STM8 chip 41 be then added to com1, com2 in charactron 52, com3, Com4 are selected corresponding pin.In general, the singlechip chip of all series of STM8 be all by SWIM interface 42 emulation with Programming, 42, SWIM interface needs, 4 connecting lines are just met, i.e., by the 18th pin (SWIM pin) of STM8 chip 41 and The 4th pin (NRST pin) of STM8 chip 41 is connect with the 2nd and the 4th pin of SWIM interface 42 respectively, then connects STM8 core Power supply required for piece 41 and earthed circuit, circuit design are more simple and convenient.

The voltage-reference 1 includes the 6th resistance R6 and the 5th capacitor C5, the first pin of the STM8 chip 41 The negative input end and the 5th capacitor C5 that comparison circuit 2 is separately connected after the 6th resistance R6 are connected, the 5th capacitor C5's is another One end ground connection.Quick PWM waveform is generated by STM8 chip 41, by obtaining effective DC voltage after voltage-reference 1 DAC obtains different DC voltage DAC by adjusting the duty ratio of PWM waveform.Fig. 5 is the first pin from STM8 chip 41 The output voltage of middle output PWM waveform, the PWM waveform is 5V, and the range of duty ratio is 0% to 100%, voltage-reference 1 Be converted to the direct current that output voltage is 0-5V according to the duty ratio of PWM waveform, the direct current electrical waveform of output as shown in fig. 6, to Adjustable reference voltage is provided for comparison circuit 2.

The display circuit 5 includes resistance group 51 and charactron 52, and the resistance group 51 includes eight in parallel identical First resistor R91, second resistance R92,3rd resistor R93, the 4th resistance R94, the 5th resistance R95, the 6th resistance R96, The 13rd pin of seven resistance R97, the 8th resistance R98, the STM8 chip 41 pass through first resistor R91 connection charactron 52 3rd pin, the 14th pin of the STM8 chip 41 pass through the 5th pin of second resistance R92 connection charactron 52, the STM8 15th pin of chip 41 passes through the 10th pin of 3rd resistor R93 connection charactron 52, and the 16th of the STM8 chip 41 is drawn Foot passes through the 1st pin of the 4th resistance R94 connection charactron 52, and the 17th pin of the STM8 chip 41 passes through the 5th resistance 18th pin of the 2nd pin of R95 connection charactron 52, the STM8 chip 41 passes through the 6th resistance R96 connection charactron 52 The 4th pin, the 19th pin of the STM8 chip 41 passes through the 7th pin of the 7th resistance R97 connection charactron 52, described 20th pin of STM8 chip 41 is by the 11st pin of the 8th resistance R98 connection charactron 52, and the of the STM8 chip 41 3 pins connect the 6th pin of charactron 52, the 8th pin of the 10th pin connection charactron 52 of the STM8 chip 41, institute The 9th pin of the 11st pin connection charactron 52 of STM8 chip 41 is stated, the 12nd pin of the STM8 chip 41 connects digital 12nd pin of pipe 52 passes through the real-time dynamic of 51 drive digital tube of resistance group 52 of the GPIO pin series connection current limliting of STM8 chip 41 Display.

Ground connection is simulated ground and is digitally separated by the 5th resistance R5, effectively including connection simulation ground and digitally It avoids digitally interfering with each other with simulation, in PCB layout, distinguish for convenience digitally with simulation, and facilitate number Copper is covered to word with simulation ground, it can also separately be debugged.

A kind of small signal high precision peak detection device of high bandwidth of the utility model allows voltage to be 0-5V, frequency 0- The positive input terminal of the detection signal input comparison circuit 2 of the random waveform of 120MHz, the negative input termination voltage of comparison circuit 2 A reference source 1, when the voltage of the positive input terminal of comparison circuit 2 is bigger than the voltage of negative input end, then comparison circuit 2 exports height Level, otherwise output low level, may be implemented in this way by input signal shaping.If input signal can be direct when being low frequency signal Identified with the external interrupt of control circuit 4, but input signal be high-frequency signal when control circuit 4 be unrecognized.Cause This, needs the signal of shaping reducing signal frequency by frequency down circuit 3, so as to be identified by control circuit 4.When control electricity It is high level that road 4, which detects, and control circuit 4 will reduce the duty ratio of the PWM exported to voltage-reference 1；When control circuit 4 is examined Measuring is low level, and control circuit 4 will increase the duty ratio of the PWM exported to voltage-reference 1, by repeatedly adjusting repeatedly The duty ratio of PWM, and all more last diminution of regulated quantity every time, it is convenient to move closer to the voltage peak of detection signal Finding out 2 output signal of comparison circuit to change from high level is low level state, and 2 output signal of comparison circuit becomes from high level Being melted into low level state that time is to detect the failing edge of signal, and reference voltage at this time is then determined as detecting the peak of signal Threshold voltage.In order to avoid maloperation, the detection process of detector arrangement is repeated, and constantly reduces the regulated quantity of duty ratio, Most accurate failing edge position gradually close to failing edge and is finally determined after taking multiple measurements, reference voltage at this time is then inspection The crest voltage for surveying signal, determining crest voltage is shown on display circuit 5.

As long as reference voltage is accurate enough, then the precision of the signal source crest voltage measured is also sufficiently high.This reality With a kind of control circuit 4 of the novel small signal high precision peak detection device of high bandwidth using STM8 chip 41, STM8 Chip 41 is 16 advanced control timers, and generated PWM waveform obtains desired reference voltage after passing through low-pass filtering. For STM8 chip 41 under 5V voltage, the PWM voltage that control circuit 4 exports is 0-5V, the PWM waveform electricity that STM8 chip 41 generates It presses, the theoretical precision of the DAC voltage after low-pass filtering is approximately equal to 0.0000763V, i.e. 0.0663mV, that is to say, that detection accuracy It can achieve 0.0663mV.

The above is only the preferred embodiment of the present invention, all institutes within the scope of the spirit and principles of the utility model Any modifications, equivalent replacements, and improvements etc. of work, should be included within the scope of protection of this utility model.

Claims (6)

1. a kind of small signal high precision peak detection device of high bandwidth, which is characterized in that including voltage-reference (1), more electric Road (2), frequency down circuit (3), control circuit (4) and display circuit (5), the control circuit (4) connect voltage-reference (1), the positive input terminal of the negative input end of the voltage-reference (1) connection comparison circuit (2), the comparison circuit (2) connects A detection signal is connect, the comparison circuit (2) passes sequentially through frequency down circuit (3), control circuit (4) and display circuit (5) and connects It connects.

2. the small signal high precision peak detection device of a kind of high bandwidth according to claim 1, which is characterized in that described Comparison circuit (2) includes comparator (21), electric source filter circuit (22) and first resistor (R3, R4), the first resistor (R3, R4 one end) is separately connected the positive input terminal of comparator (21) simultaneously and detection signal, the other end are grounded simultaneously, the power supply filter Wave circuit (22) includes third capacitor (C3) and the 4th capacitor (C4), and the one of the third capacitor (C3) and the 4th capacitor (C4) End while the positive voltage terminal and power supply for connecting comparator (21), the other end ground connection of the third capacitor (C3), the 4th electricity Hold the other end ground connection of (C4).

3. the small signal high precision peak detection device of a kind of high bandwidth according to claim 2, which is characterized in that described Frequency down circuit (3) includes first diode (D1), the 6th capacitor (C6), the 7th resistance (C7), the output of the comparator (21) End is described by connecting respectively with the 6th capacitor (C6), the 7th resistance (C7) and control circuit (4) after first diode (D1) The other end of 6th capacitor (C6) and the other end of the 7th resistance (C7) are grounded respectively.

4. the small signal high precision peak detection device of a kind of high bandwidth according to claim 1, which is characterized in that described Control circuit (4) includes STM8 chip (41), SWIM interface (42), the 7th capacitor (C7), the 8th capacitor (C8) and the 8th resistance (R8), the 4th pin of the STM8 chip (41) is connect with the 8th capacitor (C8) and the 8th resistance (R8) respectively, the 8th electricity The other end for holding (C8) is grounded, the other end connection external power supply of the 8th resistance (R8), and the 7th of the STM8 chip (41) the 8th pin of pin ground connection, the STM8 chip (41) is grounded by the 7th capacitor (C7), and the 1st of the STM8 chip (41) the Pin connects voltage-reference (1), and the 1st pin of the SWIM interface (42) connects external power supply, the SWIM interface (42) The 2nd pin connection STM8 chip (41) the 18th pin, the 3rd pin ground connection of the SWIM interface (42), the SWIM connects 4th pin of the 4th pin connection STM8 chip (41) of mouth (42).

5. the small signal high precision peak detection device of a kind of high bandwidth according to claim 4, which is characterized in that described Voltage-reference (1) includes the 6th resistance (R6) and the 5th capacitor (C5), and the first pin of the STM8 chip (41) connects the The negative input end and the 5th capacitor (C5) of comparison circuit (2) are separately connected after six resistance (R6), the 5th capacitor (C5) Other end ground connection.

6. the small signal high precision peak detection device of a kind of high bandwidth according to claim 4, which is characterized in that described aobvious Show that circuit (5) includes resistance group (51) and charactron (52), the resistance group (51) includes eight in parallel identical first Resistance (R91), second resistance (R92), 3rd resistor (R93), the 4th resistance (R94), the 5th resistance (R95), the 6th resistance (R96), the 13rd pin of the 7th resistance (R97) and the 8th resistance (R98), the STM8 chip (41) passes through first resistor (R91) the 3rd pin of charactron (52) is connected, the 14th pin of the STM8 chip (41) is connected by second resistance (R92) 15th pin of the 5th pin of charactron (52), the STM8 chip (41) passes through 3rd resistor (R93) connection charactron (52) The 10th pin, the 16th pin of the STM8 chip (41) draws by the 1st of the 4th resistance (R94) connection charactron (52) Foot, the 17th pin of the STM8 chip (41) connects the 2nd pin of charactron (52) by the 5th resistance (R95), described 4th pin of 18th pin of STM8 chip (41) by the 6th resistance (R96) connection charactron (52), the STM8 chip (41) the 19th pin by the 7th resistance (R97) connection charactron (52) the 7th pin, the 20th of the STM8 chip (41) the 11st pin of the pin by the 8th resistance (R98) connection charactron (52), the 3rd pin connection number of the STM8 chip (41) 6th pin of code pipe (52), the 8th pin of the 10th pin connection charactron (52) of the STM8 chip (41), the STM8 9th pin of the 11st pin connection charactron (52) of chip (41), the 12nd pin of the STM8 chip (41) connect digital Manage the 12nd pin of (52).