CN1324568C

CN1324568C - Double-stage peak value detector

Info

Publication number: CN1324568C
Application number: CNB031002439A
Authority: CN
Inventors: 徐哲祥; 林永裕; 陈志成
Original assignee: MediaTek Inc
Current assignee: MediaTek Inc
Priority date: 2003-01-07
Filing date: 2003-01-07
Publication date: 2007-07-04
Anticipated expiration: 2023-01-07
Also published as: CN1516118A

Abstract

The present invention relates to a peak value detector with a double-stage peak value detecting unit, which can retain the peak value for a long time and has high reaction speed. The double-stage peak value detector comprises a simulation peak value detecting unit, a simulation digital conversion unit and a digital peak value detecting unit, wherein the simulation peak value detecting unit is used for receiving and simulating an input signal, taking a first time interval as a detecting period to detect the peak value of the simulation input signals and outputting the simulation peak signal, the simulation digital conversion unit receives the simulation peak signal and converts the simulation peak signal into a digital signal, and the digital peak value detecting unit receives the digital signal, and takes a second time interval as a detecting period to detect the maximum value of the digital signal and output the digital peak signal.

Description

The peak detctor in two stages

Technical field

The present invention is about a kind of peak detctor, especially in regard to the peak detctor in a kind of two stages that have simulation and digital peak detecting unit and can keep for a long time.

Background of invention

General recordable digital audio-video laser disc (Digital versatile disk Recordable, hereinafter to be referred as DVD-R) in order correctly to detect the frequency of wavy track (wobbling tracks), can form presetting pit (PREPIT) in extra position between adjacent track, use recording address information.Because this presetting pit is formed uniformly the whole surface at DVD-R, so the reference address of this DVD-R (referenceaddress) can be from these presetting pit regeneration (reproduced).

Figure 1 shows that the Organization Chart of the cutter sweep that is used for cutting presetting pit signal in the general DVD-R cd-rom recorder.As shown in the drawing, this cutter sweep 10 utilizes a low-pass filter 11 that the radio-frequency component of input signal RF is filtered, and produces an average signal.Then, this cutter sweep utilizes a totalizer 12 that average signal is added a voltage 13, produces reference signal.At last, this cutter sweep 10 utilizes comparer 14 comparator input signal RF and reference signal to produce presetting pit signal.Generally speaking, the amplitude size of presetting pit signal can be subjected to the influence of following Several Factors, comprises the quality (quality) of DVD-R and the characteristic and the position of reflectivity (reflectance), read/write head (Pick-up Head).Therefore, if produce reference signal with the method that adds fixed voltage, then can cause miscut because of the change of presetting pit signal amplitude size with above-mentioned Fig. 1.

Fig. 2 shows the Organization Chart of the cutter sweep that is used for cutting presetting pit signal in the another kind of DVD-R cd-rom recorder.As shown in the drawing, this cutter sweep 20 comprises a low-pass filter 11, peak detection unit 22, voltage computing unit 23 and comparer 14.This cutter sweep 20 is to utilize peak detection unit 22 to detect the crest voltage of input signal (RF signal), utilizes low-pass filter 11 that the radio-frequency component of input signal is filtered simultaneously, produces an average signal.Then, utilize voltage computing unit 23 with crest voltage and average signal addition after, produce reference signal after for example being multiplied by 0.5 yield value.At last, this cutter sweep 20 utilizes comparer 14 comparator input signal RF and reference signal to produce presetting pit signal.

But the general peak value pick-up unit tends to because leakage current (current leakage) makes that the voltage of institute's breech lock (latch) is not real crest voltage if keep (hold) time longer.If but reduce the effect of leakage current, and strengthen charging capacitor, can make that then the reaction time of this peak detector is slack-off, and can't detect each peak signal.

Summary of the invention

Because the problems referred to above the purpose of this invention is to provide a kind of peak detector with two stage peak detection units, can keep peak value and reaction velocity fast for a long time.

For achieving the above object, the invention provides the peak detctor in a kind of pair of stage, it comprises:

One simulated peak detecting unit receives an analog input signal, and with a very first time be the peak value that sense cycle detects analog input signal, and output simulated peak signal;

One analog digital converting unit receives described simulated peak signal, and is converted to digital signal; And

One digital peak detecting unit receives described digital signal, and with one second time be the maximal value that sense cycle detects digital signal, and output digital peak signal;

The wherein said very first time is less than described second time.

The peak detctor in described pair of stage wherein also comprises a digital analog converter, is used for described digital peak conversion of signals is become simulating signal.

The peak detctor in described pair of stage, wherein said simulated peak detecting unit comprises:

One first detecting unit receives described analog input signal, and moves when one first control signal low level, and exports a first peak value signal;

One second detecting unit receives described analog input signal, and moves when one second control signal low level, and exports one second peak signal; And

One multiplexer receives the described first peak value signal and second peak signal, and selects signal to select the described first peak value signal or second peak signal to be output as described simulated peak signal according to one.

The peak detctor in described pair of stage wherein also comprises a control module, is used for exporting described first control signal, second control signal and selects signal, uses the action of the described simulated peak detecting unit of control.

The peak detctor in described pair of stage, wherein said control module is also exported a sampling pulse, uses the action of the described analog digital converting unit of control.

The peak detctor in described pair of stage, wherein said control module is also exported the one-period pulse, uses the action of the described digital peak detecting unit of control.

The peak detctor in described pair of stage, the cycle of wherein said recurrent pulse is described second time.

The very first time of the peak detctor in this pair stage was shorter than for second time, and the peak value that the simulated peak detecting unit is detected need not keep the oversize time, used and reduced the leakage current influence, and obtain and keep digitized peak value with the second long time.

Description of drawings

Figure 1 shows that the Organization Chart of the cutter sweep that is used for cutting presetting pit signal in the DVD-R cd-rom recorder of prior art;

Fig. 2 shows the Organization Chart of the cutter sweep that is used for cutting presetting pit signal in the another kind of DVD-R cd-rom recorder of prior art;

Figure 3 shows that the calcspar of the peak detctor in of the present invention pair of stage;

Figure 4 shows that the calcspar of simulated peak detecting unit;

The synoptic diagram of the control signal of Fig. 5 A-5D indicative control unit, wherein Fig. 5 A is that ADC sampling pulse, Fig. 5 B are that reset signal RSTA and Fig. 5 D are reset signal RSTB for selecting signal, Fig. 5 C.

Fig. 6 A-6D shows that the present invention is applied to the synoptic diagram of the part signal of the presetting pit signal detecting device in the laser disc system, and wherein Fig. 6 A is that RF signal, Fig. 6 B are that simulated peak signal, Fig. 6 C are that ADC sampling pulse and Fig. 6 D are the ADC output signal.

Fig. 7 A-7C shows that the present invention is applied to the synoptic diagram of the part signal of the presetting pit signal detecting device in the laser disc system, and wherein Fig. 7 A is that ADC output signal, Fig. 7 B are that recurrent pulse and Fig. 7 C are the digital peak signal.

Accompanying drawing number

The peak detctor in 30 pairs of stages

31 simulated peak detecting units

32 analog-digital converters

33 digital peak detecting units

34 control modules

35 digital analog converters

Embodiment

Describe the present invention's peak detctor in two stages in detail below with reference to accompanying drawing.

Figure 3 shows that the calcspar of the peak detctor in two stages of the present invention.As shown in the drawing, the peak detctor 30 in two stages of the present invention comprises a simulated peak detecting unit 31, an analog-digital converter 32, a digital peak detecting unit 33, a control module 34 and a digital analog converter 35.

Simulated peak detecting unit 31 receives an input signal, RF signal for example, and with short sense cycle input signal is carried out peak value and detect, and the output peak signal.Detect because this simulated peak detecting unit 31 carries out peak value with short sense cycle to input signal, therefore, employed charging capacitor does not need too big, not only can promote reaction velocity, and can not be subjected to the effects of leakage current.Analog-digital converter 32 receives the simulated peak voltage of simulated peak detecting unit 31 outputs, and converts digital signal to.33 receiving digital signals of digital peak detecting unit, and to detect the peak value of received digital signal than long sense cycle.Control module 34 is to be used for producing control signal, controls the action of simulated peak detecting unit 31, analog-digital converter 32 and digital peak detecting unit 33.And digital analog converter 35 is to convert the digital signal that digital peak detecting unit 33 is exported to simulating signal, utilizes for the back level.

Figure 4 shows that the calcspar of simulated peak detecting unit.As shown in the drawing, simulated peak detecting unit 31 comprises 311,312 and multiplexers 313 of two groups of peak detctors.The framework of two groups of peak detctors 311,312 is identical, just in different time point actions.It is in order to cooperate the running of analog-digital converter 32 that simulated peak detecting unit 31 uses the reason of two groups of peak detctors 311,312, when one group of peak detctor output signal allows analog-digital converter 32 samplings, another group peak detctor can continue detection peak, to avoid missing any signal.First group of peak detctor 311 is by reset signal RSTA control, and second group of peak detctor 312 controlled by reset signal RSTB.In addition, multiplexer 313 receives the output signal of peak detctor 311,312, and by selecting signal controlling, selects one of them signal output.

The synoptic diagram of the control signal of Fig. 5 A-5D indicative control unit, wherein Fig. 5 A is that ADC sampling pulse, Fig. 5 B are that reset signal RSTA and Fig. 5 D are reset signal RSTB for selecting signal, Fig. 5 C.Can recognize that from this figure when reset signal RSTA was low level, first group of peak detctor 311 detected the peak value of input signal RF, and reset signal RSTA removes the voltage that capacitor charged when being high levels.In like manner, when reset signal RSTB was low level, second group of peak detctor 312 detected the peak value of input signal RF, and reset signal RSTB removes the voltage that capacitor charged when being high levels.Can recognize from Fig. 5 B, select the t3 time just conversion of signal after the sampling of ADC sampling pulse.In addition, reset signal RSTA and the reset signal RSTB t1 time change before the sampling of ADC sampling pulse is an electronegative potential, and the t2 time after the sampling of ADC sampling pulse becomes noble potential.

Fig. 6 A-6D shows that the present invention is applied to the synoptic diagram of the part signal of the presetting pit signal detecting device in the laser disc system, and wherein Fig. 6 A is that RF signal, Fig. 6 B are that simulated peak signal, Fig. 6 C are that ADC sampling pulse and Fig. 6 D are the ADC output signal.As shown in Figure 6A, the RF signal has surging upwards, and this surging is presetting pit signal (PREPIT).The presetting pit signal detecting device promptly is used for detecting this presetting pit signal.Simulated peak detecting unit 31 of the present invention promptly receives this RF signal, and detects the peak value of this RF signal, that is detects the peak value of presetting pit signal.The simulated peak signal of Fig. 6 B is the output signal of simulated peak detecting unit 31.Can recognize that according to Fig. 6 B the simulated peak signal is cut into one section one section, and according to the ADC sampling pulse that simulated peak is signal digitalized by analog-digital converter, produce the ADC output signal of Fig. 6 D.

Fig. 7 A-7C shows that the present invention is applied to the synoptic diagram of the part signal of the presetting pit signal detecting device in the laser disc system, and wherein Fig. 7 A is that ADC output signal, Fig. 7 B are that recurrent pulse, Fig. 7 C are the digital peak signal.Digital peak detecting unit 33 of the present invention is obtained the peak value output in each cycle according to the recurrent pulse of Fig. 7 B from the ADC output signal of 7A, that is as the peak signal of Fig. 7 C.

Because the peak detctor 30 in two stages of the present invention utilizes simulated peak detecting unit 31 to detect the peak value of input signal with the short period 1, so can reduce the decay of leakage current to peak value.Afterwards, the simulated peak conversion of signals that the peak detctor 30 in two stages of the present invention utilizes analog-digital converter 32 that simulated peak detecting unit 31 is exported becomes digital signal, and utilizes the maximal value and the output of the digital signal that digital peak detecting unit 33 exported with long cycle detection analog-digital converter 32.Therefore, the peak detctor in of the present invention pair of stage can keep peak value for a long time.

Though more than with embodiment the present invention is described, therefore do not limit scope of the present invention, only otherwise break away from main idea of the present invention, the sector person can carry out various distortion or change.

Claims

1. the peak detctor in two stages is characterized in that comprising:

The wherein above-mentioned very first time is less than above-mentioned second time.

2. the peak detctor in pair stage as claimed in claim 1 is characterized in that: also comprise a digital analog converter, be used for described digital peak conversion of signals is become simulating signal.

3. the peak detctor in pair stage as claimed in claim 1 is characterized in that described simulated peak detecting unit comprises:

4. the peak detctor in pair stage as claimed in claim 3 is characterized in that also comprising a control module, is used for exporting described first control signal, second control signal and selects signal, uses the action of the described simulated peak detecting unit of control.

5. the peak detctor in pair stage as claimed in claim 4 is characterized in that described control module also exports a sampling pulse, uses the action of the described analog digital converting unit of control.

6. the peak detctor in pair stage as claimed in claim 4 is characterized in that described control module also exports the one-period pulse, uses the action of the described digital peak detecting unit of control.

7. the peak detctor in pair stage as claimed in claim 6, the cycle that it is characterized in that described recurrent pulse is described second time.