CN110098814A - A kind of automatic gain method and circuit of trans-impedance amplifier - Google Patents
A kind of automatic gain method and circuit of trans-impedance amplifier Download PDFInfo
- Publication number
- CN110098814A CN110098814A CN201910126476.2A CN201910126476A CN110098814A CN 110098814 A CN110098814 A CN 110098814A CN 201910126476 A CN201910126476 A CN 201910126476A CN 110098814 A CN110098814 A CN 110098814A
- Authority
- CN
- China
- Prior art keywords
- trans
- amplifier
- impedance amplifier
- current
- impedance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 13
- 238000001514 detection method Methods 0.000 claims description 12
- 230000005611 electricity Effects 0.000 claims description 3
- 230000003287 optical effect Effects 0.000 description 8
- 230000035945 sensitivity Effects 0.000 description 7
- 239000008186 active pharmaceutical agent Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000009514 concussion Effects 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 230000005405 multipole Effects 0.000 description 1
- 239000013307 optical fiber Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 230000011664 signaling Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
- H03F1/3211—Modifications of amplifiers to reduce non-linear distortion in differential amplifiers
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/42—Modifications of amplifiers to extend the bandwidth
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/45—Differential amplifiers
- H03F3/45071—Differential amplifiers with semiconductor devices only
- H03F3/45076—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier
- H03F3/45179—Differential amplifiers with semiconductor devices only characterised by the way of implementation of the active amplifying circuit in the differential amplifier using MOSFET transistors as the active amplifying circuit
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3084—Automatic control in amplifiers having semiconductor devices in receivers or transmitters for electromagnetic waves other than radiowaves, e.g. lightwaves
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Nonlinear Science (AREA)
- Amplifiers (AREA)
Abstract
The present invention provides a kind of automatic gain methods of trans-impedance amplifier, by separately setting input current shunt paths all the way, when input current increases, current bypass path is gradually opened, part input current is flowed through from the current bypass path, so that the current segment for flowing through feedback resistance RF reduces.The present invention additionally provides a kind of auto-gain circuit of trans-impedance amplifier according to above-mentioned method.The automatic gain method and circuit of a kind of above-mentioned trans-impedance amplifier, can be applicable in the automatic gain control circuit in various trans-impedance amplifiers, and especially in the trans-impedance amplifier of high-speed, high bandwidth, circuit structure is novel, succinct, high reliablity.
Description
Technical field
The present invention relates to electronic circuit field more particularly to trans-impedance amplifiers.
Background technique
In Modern High-Speed optical fiber telecommunications system, trans-impedance amplifier TIA plays the faint light that photodiode is generated
Current signal converts and is enlarged into voltage signal, and exports and handled to subsequent circuit.Therefore before TIA is in receiving end most
Edge, is the core devices of optical communication system receiving end, and the core index such as noise, sensitivity, dynamic range, sensitivity are determined substantially
The performance of entire reception system is determined.
The core index of typical trans-impedance amplifier circuit includes across resistance ZT, bandwidth f-3dB, equivalent input noise IIN, input
Impedance RINDeng, while the trans-impedance amplifier circuit of actual commercialization is more complicated, is mostly multipole dot system, wherein main close
Note is dominant pole ωp1And secondary pole ωp2。
In addition to this, input dynamic range is also an important indicator, is defined as saturation input optical power and sensitivity
Difference.Saturation input optical power and sensitivity are respectively defined as minimum and maximum defeated within the scope of certain permissible bit error rate
Optical power.Sensitivity is mainly determined that equivalent input noise is smaller by equivalent input noise, then sensitivity index is higher；And satisfy
It is mainly determined by factors such as the pulse-width distortions of output signal with input optical power.It can be seen that, to obtain better from above-mentioned formula
Good sensitivity index needs under the premise of bandwidth allows, and will be R across resistanceFValue is done greatly as far as possible, and bigger across hindering, then is saturated
Input optical power is then smaller.
Automatic growth control (Automatic Gain usually can all be added in the trans-impedance amplifier of practical application
Control, AGC) circuit solves this problem.I.e. in smaller input optical power, keep greatly across resistance；In larger input light function
When rate, automatic adjustment reduces across resistance, so that output signal will not generate excessive pulse-width distortion, to widen dynamic range.
AGC function generallys use that adjustable active pull-up is in parallel with feedback resistance to be realized to the adjusting across resistance.Have
Whether two kinds of common methods are excessive to will lead to the excessive pulse-width distortion of output generation to detect input optical power, first is that detection
The exchange output amplitude of TIA, as shown in Figure 1；Second is that the output DC level variation of detection TIA, as shown in Figure 2.
Both modes are all the resistance values by directly adjusting feedback resistance, and then adjust across resistance value and realize automatic gain
It adjusts.But this mode, after changing feedback resistance, in the dominant pole ω of input terminalp1Also can be changed, with input signal by
Step increases, feedback resistance RFValue gradually becomes smaller, dominant pole ωp1It is then gradually to separate origin position, i.e., mobile to high frequency position, and
Secondary pole ωp2It then remains unchanged substantially, therefore dominant pole is gradually close to time pole.It is designed in the trans-impedance amplifier of lower bandwidth
In, since the junction capacity of the photodiode of collocation application is generally large, i.e. CINIt is larger, while feedback resistance RFAlso very big, because
And dominant pole ωp1Frequency be it is relatively low, dominant pole is relatively far apart from secondary pole.Therefore, main although after with automatic gain control
Pole is mobile to secondary pole, but two nodes are still able to maintain larger distance, will not generate serious stability problem.And in height
Speed, ultrahigh speed, in 10Gbps/25Gbps or the design of the trans-impedance amplifier of the above rate, CIN/RFIt cannot all be designed too big,
Therefore dominant pole distance time pole location is closer, when automatic gain control loop has adjusted RFAfter value, dominant pole is gradually
Close to time pole, it will generate serious stability problem, be rendered as amplitude frequency curve in high frequency treatment and generate great peak value, feedback
The stability threshold of loop declines, and generates resonance or concussion, seriously affects high speed signaling quality.Therefore, these traditional are automatic
Gain control is no longer desirable for the trans-impedance amplifier application of high bandwidth.
Summary of the invention
The main technical problem to be solved by the present invention is to provide a kind of automatic gain method of trans-impedance amplifier and circuit,
It can be applicable in the automatic gain control circuit in various trans-impedance amplifiers, especially the trans-impedance amplifier of high-speed, high bandwidth
In, circuit structure is novel, succinct, high reliablity.
In order to solve the above technical problems, it the present invention provides a kind of automatic gain method of trans-impedance amplifier, separately sets
Input current shunt paths all the way, when input current increases, current bypass path is gradually opened, and part input current is from described
Current bypass path flows through, so that the current segment for flowing through feedback resistance RF reduces.
The present invention also provides a kind of auto-gain circuit of trans-impedance amplifier, including nMOS pipe N0, drain electrode connect across
The input terminal of impedance amplifier, source electrode connect in a low AC impedance voltage node Vinb module, and the voltage value of Vinb module connects
Closely but the input terminal voltage Vin of slightly below trans-impedance amplifier；
The output end of trans-impedance amplifier accesses a signal strength detection module, for the defeated of detection senses trans-impedance amplifier
Enter signal strength, and be converted into a d. c. voltage signal, then is input to the inverting input terminal of a feedback amplifier OP.Feedback fortune
The non-inverting input terminal for putting OP then connects on a reference voltage VREF；The output end of feedback amplifier OP then connects on the grid of N0.
When the input current signal of trans-impedance amplifier is smaller, the inverting input terminal voltage of amplifier OP is higher than reference voltage
VREF, amplifier OP export low level, and N0 is in an off state, and input current only passes through feedback resistance RFCirculation；
When input current signal incrementally increases, the voltage of the inverting input terminal of amplifier OP is gradually reduced, amplifier OP output
Voltage be stepped up, N0 gradually opens conducting；The part AC compounent and DC component of input current are shunted by NO.
Compared to the prior art, technical solution of the present invention have it is following the utility model has the advantages that
The invention proposes a kind of auto-gain circuits of trans-impedance amplifier, do not adjust and change feedback resistance RF, but logical
It crosses and separately sets input current shunt paths all the way, when input current is larger, gradually open the path automatically, shunt part input
Electric current (including DC component and AC compounent) so that the current segment for flowing through feedback resistance RF reduces, so as to avoid across
The output signal of impedance amplifier generates serious pulse-width distortion.
Detailed description of the invention
AGC theory structure of the Fig. 1 in the prior art based on detection exchange output amplitude
AGC theory structure of the Fig. 2 in the prior art based on detection output DC level
Fig. 3 is the schematic illustration in the preferred embodiment of the present invention；
Fig. 4 is the circuit diagram of the preferred embodiment of the present invention.
Specific embodiment
Below in conjunction with the drawings and specific embodiments, the present invention will be further described.
The present invention provides a kind of automatic gain methods of trans-impedance amplifier, separately set input current shunt paths all the way,
When input current increases, current bypass path is gradually opened, and part input current is flowed through from the current bypass path, so that stream
The current segment for crossing feedback resistance RF reduces.
Specifically, with reference to Fig. 3, a kind of auto-gain circuit of trans-impedance amplifier, including nMOS pipe N0, drain electrode is connect
The input terminal of trans-impedance amplifier, source electrode connect in a low AC impedance voltage node Vinb module, the voltage value of Vinb module
Close but slightly below trans-impedance amplifier input terminal voltage Vin；
The output end of trans-impedance amplifier accesses a signal strength detection module, for the defeated of detection senses trans-impedance amplifier
Enter signal strength, and be converted into a d. c. voltage signal, then is input to the inverting input terminal of a feedback amplifier OP.Feedback fortune
The non-inverting input terminal for putting OP then connects on a reference voltage VREF；The output end of feedback amplifier OP then connects on the grid of N0.
When the input current signal of trans-impedance amplifier is smaller, the inverting input terminal voltage of amplifier OP is higher than reference voltage
VREF, therefore its output voltage will be low level, N0 is in close state, and conducting resistance is huge, therefore input current only leads to
Cross feedback resistance RFCirculation.
When input current signal incrementally increases, the voltage of OP inverting input terminal will be gradually reduced, and output voltage is gradually
It increases, N0 also will gradually open conducting.Since the drain electrode of N0, source voltage are close, i.e. its VDSVery little, therefore N0 will be in deep line
Property area, conducting resistance, conducting electric current can derive are as follows:
As the V of N0GSVoltage is greater than threshold voltage VTHAfterwards, it is gradually connected, conducting resistance is by VGSIt determines, but the electricity flowed through
Stream is by VGSAnd VDSIt determines.Therefore after input current is constant, output voltage meeting after feedback control loop adjusts of amplifier OP is fed back
Stablize in an end value, therefore the V of N0GSAlso it will keep constant, IDValue is by VDSIt determines.But when input current is AC signal,
Then VDS=Vin-VinbAnd AC signal, therefore flow through the electric current I of N0DIt is also AC signal.Therefore, finally entire automatic
After gain control loop automatically adjusts and stablizes, N0 has shunted the DC component and AC compounent of part input current.
The circuit diagram of a complete trans-impedance amplifier, NMOS tube N0/N1/N2, electricity are provided with further reference to Fig. 4, Fig. 4
Hinder R0, tail current I0, feedback resistance RFConstitute a kind of common trans-impedance amplifier structure.The source electrode of NMOS tube N3 is grounded, grid
Drain electrode is connected, and connects with the source electrode of NMOS tube N4, and the grid of N4 is biased by voltage Vb4, one end of drain electrode and resistance R1
Connect, the another of R1 terminates to power supply.To extract common-mode voltage defeated by RC filter (R2/C0) for the output end of trans-impedance amplifier
Enter the inverting input terminal to amplifier OP, the non-inverting input terminal of amplifier is biased by reference voltage VREF.The drain electrode of NMOS tube N5 connects
In the input terminal (i.e. node Vin) of trans-impedance amplifier, source electrode is connected to the grid (i.e. node Vinb) of N3, and grid is connected to the output of OP
End.
By design appropriate, Vinb can be made to be slightly below Vin, VREF is less than output of the trans-impedance amplifier without input when
Common-mode voltage Vout_noinput.Therefore, as input current IINWhen smaller, the output common mode voltage Vout of trans-impedance amplifier is big
In VREF, therefore amplifier OP output voltage is low-voltage, and N5 is off state；When input current incrementally increases, output common mode
Level Vout is then gradually reduced, and amplifier OP output voltage then incrementally increases, when being increased above VTH_N5When+Vinb, N5 is gradually opened
It opens, beginning shunts the alternating current and direct current component of input current, clamps the output common mode level of trans-impedance amplifier
System in VREF value or so, also accordingly clamped down in a certain range by amplitude output signal, is avoided and is generated serious pulse-width distortion
Problem.
Other than the present embodiment, the structure of trans-impedance amplifier can also be other various structures, including bipolar technique
's.Detection to signal strength can also be other a variety of methods except through detecting the common-mode signal of output node, than
Such as by the range value of detection output signal, by detecting circuit, the range value conversion D. C. value of AC signal will be exported, then with
Reference value is compared differentiation etc..
The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and those skilled in the art can
To readily appreciate that variation disclosed in this invention or technical scope.Alternative solution is intended to cover within the scope of the invention.Cause
This, protection scope of the present invention should be determined by the scope of the claims.
Claims (2)
1. a kind of automatic gain method of trans-impedance amplifier, it is characterised in that: separately set input current shunt paths all the way, inputting
When electric current increases, current bypass path is gradually opened, and part input current is flowed through from the current bypass path, so that flowing through anti-
The current segment of feed resistance RF reduces.
2. a kind of auto-gain circuit of trans-impedance amplifier, it is characterised in that: including nMOS pipe N0, drain electrode connects amplifies across resistance
The input terminal of device, source electrode connect in a low AC impedance voltage node Vinb module, and the voltage value of Vinb module is close but omits
Lower than the input terminal voltage Vin of trans-impedance amplifier；
The output end of trans-impedance amplifier accesses a signal strength detection module, and the input for detection senses trans-impedance amplifier is believed
Number intensity, and it is converted into a d. c. voltage signal, then be input to the inverting input terminal of a feedback amplifier OP.Feed back amplifier OP
Non-inverting input terminal then connect on a reference voltage VREF；The output end of feedback amplifier OP then connects on the grid of N0.
When the input current signal of trans-impedance amplifier is smaller, the inverting input terminal voltage of amplifier OP is higher than reference voltage VREF,
Amplifier OP exports low level, and N0 is in an off state, and input current only passes through feedback resistance RFCirculation；
When input current signal incrementally increases, the voltage of the inverting input terminal of amplifier OP is gradually reduced, the electricity of amplifier OP output
Pressure is stepped up, and N0 gradually opens conducting；The part AC compounent and DC component of input current are shunted by NO.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910126476.2A CN110098814A (en) | 2019-02-20 | 2019-02-20 | A kind of automatic gain method and circuit of trans-impedance amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910126476.2A CN110098814A (en) | 2019-02-20 | 2019-02-20 | A kind of automatic gain method and circuit of trans-impedance amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110098814A true CN110098814A (en) | 2019-08-06 |
Family
ID=67443904
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910126476.2A Pending CN110098814A (en) | 2019-02-20 | 2019-02-20 | A kind of automatic gain method and circuit of trans-impedance amplifier |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110098814A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111026213A (en) * | 2019-11-07 | 2020-04-17 | 中科威发半导体（苏州）有限公司 | Current-to-voltage circuit and power supply method thereof |
| CN113204133A (en) * | 2021-04-21 | 2021-08-03 | 北京航天控制仪器研究所 | Electro-optical modulator bias voltage automatic control device based on FPGA |
| CN113890493A (en) * | 2021-09-03 | 2022-01-04 | 厦门优迅高速芯片有限公司 | Transimpedance amplifier with switchable transimpedance gain and single-ended-to-differential amplification circuit |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4415803A (en) * | 1980-10-22 | 1983-11-15 | Bell Telephone Laboratories, Incorporated | Optical receiver with improved dynamic range |
| US4623786A (en) * | 1984-11-07 | 1986-11-18 | At&T Bell Laboratories | Transimpedance amplifier with overload protection |
| DE69325569D1 (en) * | 1993-03-04 | 1999-08-12 | Cit Alcatel | Shunt regulator for a power supply |
| JP2012257070A (en) * | 2011-06-09 | 2012-12-27 | Nippon Telegr & Teleph Corp <Ntt> | Transimpedance amplifier |
| CN104242844A (en) * | 2014-09-25 | 2014-12-24 | 厦门优迅高速芯片有限公司 | Trans-impedance amplification circuit capable of realizing automatic gain control |
| CN108173524A (en) * | 2018-02-08 | 2018-06-15 | 厦门亿芯源半导体科技有限公司 | Suitable for the double loop automatic gain control circuit of high bandwidth TIA |
| CN108199694A (en) * | 2018-01-19 | 2018-06-22 | 厦门优迅高速芯片有限公司 | A kind of auto gain control method and circuit that can be applied to burst trans-impedance amplifier |
| CN209627336U (en) * | 2019-02-20 | 2019-11-12 | 厦门优迅高速芯片有限公司 | A kind of auto-gain circuit of trans-impedance amplifier |
-
2019
- 2019-02-20 CN CN201910126476.2A patent/CN110098814A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4415803A (en) * | 1980-10-22 | 1983-11-15 | Bell Telephone Laboratories, Incorporated | Optical receiver with improved dynamic range |
| US4623786A (en) * | 1984-11-07 | 1986-11-18 | At&T Bell Laboratories | Transimpedance amplifier with overload protection |
| DE69325569D1 (en) * | 1993-03-04 | 1999-08-12 | Cit Alcatel | Shunt regulator for a power supply |
| JP2012257070A (en) * | 2011-06-09 | 2012-12-27 | Nippon Telegr & Teleph Corp <Ntt> | Transimpedance amplifier |
| CN104242844A (en) * | 2014-09-25 | 2014-12-24 | 厦门优迅高速芯片有限公司 | Trans-impedance amplification circuit capable of realizing automatic gain control |
| CN108199694A (en) * | 2018-01-19 | 2018-06-22 | 厦门优迅高速芯片有限公司 | A kind of auto gain control method and circuit that can be applied to burst trans-impedance amplifier |
| CN108173524A (en) * | 2018-02-08 | 2018-06-15 | 厦门亿芯源半导体科技有限公司 | Suitable for the double loop automatic gain control circuit of high bandwidth TIA |
| CN209627336U (en) * | 2019-02-20 | 2019-11-12 | 厦门优迅高速芯片有限公司 | A kind of auto-gain circuit of trans-impedance amplifier |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111026213A (en) * | 2019-11-07 | 2020-04-17 | 中科威发半导体（苏州）有限公司 | Current-to-voltage circuit and power supply method thereof |
| CN113204133A (en) * | 2021-04-21 | 2021-08-03 | 北京航天控制仪器研究所 | Electro-optical modulator bias voltage automatic control device based on FPGA |
| CN113890493A (en) * | 2021-09-03 | 2022-01-04 | 厦门优迅高速芯片有限公司 | Transimpedance amplifier with switchable transimpedance gain and single-ended-to-differential amplification circuit |
| CN113890493B (en) * | 2021-09-03 | 2024-04-12 | 厦门优迅高速芯片有限公司 | Trans-impedance gain switchable trans-impedance amplifier and single-ended-to-differential amplifying circuit |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN209627336U (en) | A kind of auto-gain circuit of trans-impedance amplifier | |
| CN110098814A (en) | A kind of automatic gain method and circuit of trans-impedance amplifier | |
| CN204046530U (en) | A kind of low noise trans-impedance amplifier and Optical Receiver Preamplifier thereof | |
| CN110212875A (en) | A kind of linear trans-impedance amplifier and its design method and application | |
| CN102067445B (en) | Perform amplifier and the optical module of gain control | |
| CN109861661A (en) | A kind of trans-impedance amplifier and trans-impedance amplifier circuit | |
| CN104242844B (en) | It is a kind of can realize automatic growth control across resistance amplifying circuit | |
| CN114039562B (en) | Low-cost over-frequency high-speed trans-impedance amplifier | |
| KR100682822B1 (en) | High speed line equalizer | |
| CN102638317A (en) | Signal loss detection circuit and method and amplifier | |
| CN108173524A (en) | Suitable for the double loop automatic gain control circuit of high bandwidth TIA | |
| CN108199696A (en) | A kind of trans-impedance amplifier automatic gain control circuit | |
| CN114551426B (en) | Trans-impedance amplifier chip with WiFi interference signal capability and packaging method thereof | |
| CN113659949A (en) | Automatic gain control circuit and method of transimpedance amplifier circuit | |
| CN106505961B (en) | The automatic gain control circuit of quick response | |
| CN114050793B (en) | Amplification method adopting low-cost over-frequency high-speed transimpedance amplifier | |
| CN108199694A (en) | A kind of auto gain control method and circuit that can be applied to burst trans-impedance amplifier | |
| CN113890493B (en) | Trans-impedance gain switchable trans-impedance amplifier and single-ended-to-differential amplifying circuit | |
| CN110677134A (en) | Self-adaptive bandwidth adjusting circuit | |
| CN110535534A (en) | Optical receiver front end and the method for receiving optical signal | |
| CN109039473A (en) | The front-end circuit and its low noise acoustic processing method of high-speed light receiver | |
| US20180076800A1 (en) | Cross-point offset adjustment circuit | |
| WO2023280137A1 (en) | Transimpedance amplifier and transimpedance amplifier control method | |
| CN110557098A (en) | positive feedback transimpedance amplification circuit and adjustment method | |
| CN209627328U (en) | Burst trans-impedance amplifier with reset signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |