TW200412708A - Start-up overshoot inhibition for power converter - Google Patents

Abstract

A start-up overshoot inhibition technique for a power converter is addressed. The start-up overshoot inhibition technique according to the present invention basically uses a reference voltage generator to precipitate the rising slopes of multiple output voltages of a power converter to become mutually unanimous during start-up period, and thereby avoid the occurrence of system faults in the power converter due to the instantaneously rapid increase of output voltage thereof during start-up period.

Description

200412708 V. Description of the invention (1) Technical field to which the invention belongs The present invention relates to a power converter, and more particularly, the present invention relates to a start-up overshoot inhibition technology for a power converter. The prior art is shown in the first figure, which is a circuit diagram of a conventional synchronous rectifier power converter. As shown in the first figure, a conventional synchronous rectifier power converter usually includes a switching control circuit 101, a magnetic saturation amplifier 丨 〇2, a switching circuit 103 ′-an output filter, a wave filter 104, a The resistive voltage divider 105 and a reference voltage generator 106. The magnetic saturation amplifier (magnetic amp 1 1 f 1 er) 1 02 is to amplify the parent current voltage VAC induced by the secondary winding end of a transformer τ 1 in a magnetic coupling manner, and the amplified The AC voltage is converted into a DC voltage by the on / off operation of the switching circuit 103. The generated DC voltage is rectified and smoothed by an output filter (0UtpUt filter) 104 composed of an inductor la and a capacitor CA, and an output voltage v0 is generated and provided to a load (not shown). In addition, the output voltage V0 returns a partial output voltage (fractional 〇utput v〇ltage) Vs to a switch control circuit 101 through a resistive voltage divider 105 composed of resistors rA and RB. . The switch control circuit (switch c⑽tr (3l circuit) 101 utilizes an internal comparator (not shown in the figure for simplicity) to compare part of the output voltage VS with a reference voltage generator 106. Reference voltage

Page 6 200412708 V. Description of the invention (2)

Vref is compared, and a pulse width modulation signal (called a modulation signal, PWM Signal) is generated accordingly. Within the switch control circuit 1001 =-drive circuit (which is usually completed by _transistor), which is based on the pulse width modulation signal of the -width drive switch circuit 1 () 3 to turn on / off to control the switching circuit 103 Switching duty cycle), and then stabilize the output voltage at the same time to complete the synchronous rectification. On the other hand, an internal management circuit (which is not shown in the figure) sends a remote on / off signal (remote 0N / 0FF signal) to provide the output voltage to the remote power receiving device. , Such as motherboards or hard disks, etc. Power converters generally used in power supply systems usually provide multiple output voltages with a predetermined voltage level, such as 5V or 3 · 3V, each output voltage is provided to a Or multiple electrons δ that can be properly operated at this voltage are available. As shown in the second graph (a), a first output voltage ^ is set to a fixed rise during its start-up period (0-tl). The slope climbs to a stable level (such as 5V). At this time, the power converter enters the startup mode. The so-called start-up time or set-up Ume refers to the power supply from the input The time from the termination of the power supply until its output voltage rises within the regulation range. Similarly, a second output voltage ν〇 ^ 2 rises with a fixed rising slope within its startup time (〇- t2). To a voltage level (eg 3.3V) '' And the slope of the rising portion of the first output voltage v0uti and the slope of the rising portion of the second output voltage Vout2 are close to each other. When the two output voltages have respectively stabilized, the power conversion 3 can output two different types. Stable DC voltage basins of different levels — ,,,, and 20042004708 V. Description of the invention (3) load, and enter normal mode operation .: And the 'power converter' is generally a dynamic load (dynamic load) η · During the operation of the radial cutting L, the load of the load is e ::: The actual device is at the start time. Therefore, there will be "the output voltage will exceed the set value because of the output. An excessively large phenomenon has occurred. As is not the case in the first 0 (b), the output voltage v0utl of the younger brother is instantaneously outputting an excessively large voltage due to its phase m ', which makes the amplitude of the electric power increase. However, the same The j = slope of the second output voltage V〇ut2 remains constant, so that at a certain dead point t3 during the startup period of the power converter, the instantaneous voltage value of the first output voltage ¥ 〇111: 1 and the second Instantaneous power of output voltage V0ut2 The difference between the voltage values exceeds its stable voltage value =, the difference, for example, 5ν — 3 · 3ν = 1 · 7V, causes the output of the power converter to exceed the voltage that the load component can withstand and cause malfunction, which causes a crash. This phenomenon that the system malfunctions due to the instantaneous rapid rise in output voltage during the startup period is called start-up overshoot (set-up overshoot). Therefore, what is needed is to propose a power conversion The device's startup overshoot prohibition technology 'to avoid the problem of startup overshoot during power converter startup' to ensure the normal operation of the system. SUMMARY OF THE INVENTION A more general aspect of the present invention is accomplished by a power converter.

Page 8 200412708 V. Description of the invention (4) = It includes at least one magnetic saturation amplifier, each of which is magnetically coupled ^ = one of the windings and one of the AC voltages, and amplifies the AC voltage to = a switch Each circuit is connected to the magnetic saturation amplifier. Each system converts the amplified AC voltage into a DC voltage due to its closing operation. At least one wheel-out filter is coupled to the switching circuit. Each system is used to provide A pre-rounded output voltage to a load, at least one switch control circuit, each system = two output voltages are compared with a reference voltage to generate a pulse width modulation = sign to control the on / off operation of the switch circuit, And a reference voltage is generated and coupled to the switch control circuit, which provides a reference voltage to each switch control circuit respectively, and the reference voltage causes each predetermined output voltage to have a rising slope during a startup period. Nearly consistent. In a narrow sense, the above-mentioned reference voltage generator includes a linear voltage generating circuit 'for generating a voltage having a rising slope characteristic, and a first reference voltage generating circuit for limiting the voltage having a rising slope characteristic according to a predetermined voltage. Voltage to generate a first reference voltage and a second reference voltage generating circuit for enabling the voltage with a rising slope characteristic to start after a short period of time and increasing the slope of the voltage to generate a second reference voltage . The previous description of the present invention and the advantages and features of the present invention can be obtained through a detailed description of the following embodiments in conjunction with the following figures, to gain a deeper understanding. Simple diagram description The first diagram is a schematic diagram showing a circuit diagram of a conventional power converter;

Page 9 200412708 V. Description of the invention (5) The second diagram (a) shows the output voltage waveform diagram of a conventional power converter with a plurality of predetermined DC voltage outputs; the second diagram (b) shows a plurality of predetermined The waveform diagram of the start-up overshoot phenomenon of the output voltage of the power converter with a DC voltage output; the third diagram is a circuit tone of one of the power converters of the present invention, and the diagram · the fourth diagram shows the power converter of the present invention. Switch 2 °, a circuit diagram; the fifth diagram of the industrial circuit shows a reference circuit diagram of the power converter of the present invention; the sixth diagram of the generator shows the reference circuit of the power converter of the present invention. The voltage waveform diagram of the circuit circuit node; and the seventh diagram of the ~ generator shows the inrush current limit induced voltage, the far-end number, the first reference voltage, and the voltage f / offset / time percent of the second reference voltage. Component symbol description: 1 0 1 switch control circuit 102 magnetic saturation amplifier 1 0 3 switch circuit 1 0 4 output filter 105 resistive voltage divider 106 reference voltage generator 200, 201 circuit component 2 0 2, 2 0 3 switch Control circuit 2 0 4, 2 0 5 Magnetism and amplification write 200412708 V. Description of the invention (6) 2 0 6, 2 0 7 Switch circuit 2 0 8, 2 0 9 Output filter 210, 211 Resistive voltage divider 212 Reference voltage generator 2 1 3 Error amplifier 2 1 4 Drive circuit 3 0 1 Comparator 3 0 2 Current source 3 0 3, 3 0 4 Switch 3 0 5 Voltage follower 3 0 6 Voltage limiter 307 Fixed voltage 308 Fixed voltage 3 0 9 voltage subtractor 31 0 first quadrant chopper 311 amplifier 3 1 2 voltage limiter 315 linear voltage generating circuit with rising slope 316 first reference voltage generating block 317 second reference voltage generating block A circuit diagram of one of the invention's power converters is shown in the third figure. The power converter of the present invention is configured to provide a large number of reservations.

200412708 Fifth, the output voltage of invention description (7), and in this preferred embodiment, the voltage is exemplified, but the same principle and the two predetermined output voltages provide more than two predetermined output voltages. The flute can be further expanded to a number of circuit components (20, 20), each converter including two sets to generate a predetermined output voltage. The circuit = circuit component is configured with a large device 204, which is an on / off of the secondary 206 of magnetically coupled square earth including a magnetically saturated winding winding resistance terminal, undervoltage τ 1 secondary 206 The operation is converted into DC. The ^ pass circuit is composed of an inductor U and a capacitor C1m. The DC voltage of ^ = ^ = is smoothed (—), and a ΐ: = 皮 器 2 ”rectifier and load are generated. (Not shown). Similarly, the circuit component 2 i outl is provided to the device m, which is magnetically coupled = 〇1 = a magnetic saturation amplifier w P β A > _ # r is not a transformer The auxiliary winding DC voltage of Ding 1. The generated DC voltage is rectified and smoothed by the output wave filter 209 composed of ^ -inductor L2 and -capacitor C2 to generate a second output voltage v〇ut2 Provided to a load (not shown). In addition, the first output voltage v0utl returns a portion of the output voltage vsi to a switch control circuit via a resistive voltage divider 21 composed of resistors R1 and R2. 202. The switch control circuit 202 uses an internal comparator (not shown in the figure for the sake of simplicity). Compare part of the output voltage vsi with a first reference voltage Vrefl provided by a reference voltage generator 212, and generate a pulse width modulation signal (pUlse-width modulation signal, PWM signal) accordingly. . Switch control circuit 202

Page 12 200412708 V. Description of the invention (8) --- Circuit (_ which is usually completed by a transistor), which is based on the pulse width modulation signal = one shot driving circuit 2206 is turned on / off to control the switch The circuit duty cycle of the switching task 忧 ^^^ is called ^^^^^ 'and then at the same time: the size of the output voltage Voutl to complete the synchronous rectification. Similarly, the first output voltage Vout2 returns a portion of the output voltage vs2 to a switch #control circuit 203 via a resistive voltage divider 211 composed of resistors R3 and R4. The switch control circuit 2 〇3 uses an internal comparator (not shown in the figure for simplicity of description) to compare part of the output voltage vs2 with a reference voltage comparator (reference v〇ltage generatr) 212

For comparison, a second reference voltage Vref 2 is compared, and a pulse width modulation signal (pWM signal) is generated accordingly. A driving circuit inside the switch control circuit 203 (which is usually completed by an electronic printer) is to drive the switch circuit 207 on / off according to one of the pulse width modulation signals, thereby controlling the switching task of the switch circuit 207. (Switching duty cycle), and then simultaneously stabilize the magnitude of the second output voltage Vout2 to complete synchronous rectification. On the other hand, a housekeeping circuit (not shown in the figure) will send a remote ON / OFF signal (remote ON / OFF signal) to provide the output voltage Voutl or Vout2 to the remote end. Powered devices, such as motherboards or hard drives, etc. The fourth diagram shows a schematic circuit diagram of one of the switch control circuits 202, and the operation principle of the eight circuits will be described as follows. It should be noted that the switch control circuit 002 has the same circuit structure as the switch control circuit 203, and its circuit operation principle should be similar to that of the switch control circuit 203.

Page 13 200412708

The switch control circuit 202 includes an error amplifier 213, i is a ^^ xw,. ,,, has an inverting input A ^ Unverting terrainal) receives a part of the output voltage vsi provided by the voltage divider 21, and has a The non-inverting input terminal (n0n — ”inverting terminal) receives one of the first reference voltages Vrefl provided by the reference voltage comparator 212. Part of the output voltage VS1 provided by the voltage divider 210 is via the error amplifier 213 and the reference A first reference voltage Vrefl provided by the voltage comparator 212 is used for comparison, and a pulse width modulation signal is input to a driving circuit 214. The preferred one is constructed by a bipolar = surface transistor (BJT). The driving circuit 214 drives the switching circuit 206 to be turned on or off according to the width of the pulse signal, thereby adjusting the voltage value of the output voltage. The basic principle of the invention to achieve the overshoot prohibition is provided to adjust The reference voltage of the switching control circuit of the output voltage is set with a time delay when the power converter starts (tiine heart 13 magic and adjust its rising slope to force The rising slope of the output voltage during the start-up period changes accordingly, which means that the rising slopes of the output voltages during the start-up time are nearly the same, which can effectively avoid the occurrence of startup overshoot. 0 Please refer to the fifth figure, According to a preferred embodiment of the present invention, the reference voltage is 212. The circuit structure includes a comparator 3101 having an inverting input terminal N1 for receiving one of the secondary winding terminals from the transformer. Inrush current limit sense vQUage B ^ ense 'The voltage waveform is shown in Figure 7' and a non-inverting input receiving-fixed voltage 307. Comparator 3101 will inrush current limit induction voltage

200412708 V. Description of the invention (ίο) The voltage Bsense is compared with the fixed voltage 307, and a switch control signal VSW is generated according to the comparison result to a linear voltage generating circuit 3 1 5 with a rising slope. The linear voltage generating circuit 3 5 with a rising slope includes switches 30 3, 304, a current source 302, a capacitor CS, and a voltage follower 305. The switch 303 switches its on / off state according to a state of the switch control signal VSW, and the capacitor has one end coupled to a ground terminal. When the switch 3 is in the off state, the current source 30 charges the capacitor cs and stores energy in the capacitor cs. When the switch 3 is in the on state, the capacitor CS is discharged to a non-inverting input terminal of the voltage follower 305 through the circuit node ⑽. Therefore, the capacitor CS is located on a non-inverting input terminal of the voltage follower 30 The voltage is a linear voltage VCS 'with a rising slope. The voltage waveform is shown in the sixth figure. A linear voltage vcs with a rising slope at the circuit node N2 is then coupled to the circuit node N3 by a voltage follower 305. The linear voltage Ks with a rising slope located on the circuit node NJ3 is then transmitted to the Ditoco voltage generation block 316 and a second reference voltage generation block 3 17 respectively, and is applied to one of the first reference voltage generation blocks respectively. The circuit node N5 and the second reference voltage generate a circuit node N4 inside the block 317. As shown in the fifth figure, the reference voltage generating benefit 212 of a preferred embodiment of the present invention further includes a diode 01, which has an anode to receive a remote on / off signal, and a cathode & , Which is connected to the first reference voltage generating block # 6-circuit node N5. The voltage waveform of the remote on / off signal is shown in Figure 7. As shown in Figure 7, when the far-end on / off signal bit

Page 15 200412708 V. Description of the invention (11)

In the on state (0 N), the actual voltage level is a low voltage, which turns off a polar body, and the first reference voltage vreH and the second reference voltage Vref2 are linear by a rising slope. The voltage is yes. When the operation on / off signal is in the off (0 F F) state, its actual voltage level is a high voltage. If at some time during this period, the instantaneous value difference between the voltage level of the remote on / off signal and the linear voltage vcs of the rising slope is less than the threshold value of the pole D1, the two poles The body D1 is still in the off state, and the first reference voltage Vref 1 and the second reference voltage Vref2 are also determined by the linear voltage vcs with a rising slope. However, the difference between the instantaneous voltage value between the voltage level of the remote on / off signal and the linear voltage VCS of the rising slope is greater than the threshold value of the diode pi, and the diode D1 will be turned on, and it is assumed that the diode The body D1 is an ideal diode, which means that it will not generate any voltage drop at its terminals. One of the circuit nodes N5 inside the first reference voltage generation block 316 and one inside the second reference voltage generation block 317 The circuit node N4 will receive one of the high voltages represented by the remote on / off signal during the off (FF) period, and the first reference voltage Vrefl and the second reference voltage Vref2 are determined by this high voltage.

Therefore, in the first reference voltage generating block 316, when the remote on / off signal is within the ON (0 N) period, the node n 5 receives a linear voltage VCS with a rising slope, which passes through a voltage limiter. (Voltage limiter) 306 is limited to a peak voltage (peak vOitage) at a fixed voltage level, and the formed voltage is regarded as a first reference voltage Vrefl ', and its voltage waveform is shown in the sixth Figure and Figure 7 at the far end

Page 16 200412708 V. Description of the invention (12) Part of the ON / OFF signal during the opening period. When the remote on / off signal is in the OFF period and the instantaneous voltage difference between the voltage level of the remote on / off signal and the linear voltage vcs of the rising slope is greater than the threshold value of diode D1 (threshold value ), The node N5 receives the remote on / off signal voltage. Therefore, the first reference voltage formed by "1" will be one of the high DC voltages with a fixed level, and its voltage waveform is shown in the part during the remote on / off signal off period. Similarly, the In the second reference voltage generating block 317, when the remote on / off signal is within the ON period, the linear voltage VCS with a rising slope is consumed to the circuit node N4, and is connected with a voltage subtractor 3 09. The fixed voltage is subtracted from 308, and a reduced voltage VREDUCED is obtained. The voltage waveform is shown in the sixth figure. The reduced voltage VREDUCED is further filtered by the first quadrant choppei ^ 310 to filter out components other than its first quadrant to obtain a cut-off voltage with a two-day delay delay effect. VCH〇ppED, whose voltage waveform is shown in the sixth figure. The cut-off voltage VChoopped is amplified by an amplifier 3 11 to obtain an amplified voltage VAMP, which has an increasing slope. The voltage waveform is shown in the sixth figure. Finally, the amplified voltage VAMP is limited by a voltage limiter 312 to a peak voltage at a fixed voltage level, and the formed voltage is regarded as a second reference voltage Vref2. Its voltage waveform is also displayed in the sixth Figure. On the other hand, when the remote on / off signal is within the OFF (0FF) period, the high voltage represented by the remote on / off signal will be coupled to the circuit node. This DC with a fixed level The high voltage is then passed through a voltage subtractor 309 to make it a fixed voltage 308.

Page 17 200412708 V. Description of the invention (13) Subtraction 'is again amplified by the amplifier 3 11 to generate a second reference voltage Vref2. The second reference voltage during this period is displayed in the corresponding time region of the seventh graph with a voltage waveform of 2. From the above description and the voltage waveforms of each circuit node, it can be found that the use of the startup overshoot of the present invention The forbidden technology can adjust the time delay and rising slope of the reference voltage positively. It can force the rising slope of each output voltage to be close to the same during the startup period of the power supply, and it can eliminate the startup overshoot that may occur under multiple output voltages. Prohibition Issues: Even though the present invention has been described in detail by the above embodiments and can be modified in various ways by those skilled in the art, it is not inferior to those intended to be protected by the scope of patent application.

Page 18 200412708 Brief description of the diagram The first diagram is a diagram showing a circuit t according to a conventional power converter; the second diagram (a) shows a conventional power converter with a plurality of predetermined DC voltage outputs. Output voltage waveform diagram; the second diagram (b) is a waveform diagram showing a startup overshoot phenomenon of the output voltage of a power converter with a plurality of predetermined DC voltage outputs; the third diagram is a circuit of a power converter of the present invention Schematic diagram; The fourth diagram is a circuit diagram of a switching control circuit of the power converter of the present invention; the fifth diagram is a circuit diagram of the reference signal generator of the power converter of the present invention; the sixth diagram is a schematic diagram of the present invention; Voltage waveform diagrams of the respective internal circuit circuit nodes of the reference signal generator of the power converter; and the seventh diagram shows the inrush current limit induced voltage, the remote on / off signal, the first reference voltage and the second reference voltage Voltage waveform diagram.

Page 19

Claims (1)

200412708 6. Scope of patent application 1. A power converter for providing a plurality of predetermined output voltages, including: at least one magnetic saturation amplifier, each of which is magnetically coupled to an AC voltage on a winding of a transformer, and Amplify the AC voltage; at least one switching circuit is coupled to the magnetic saturation amplifier, each of which converts the amplified AC voltage into a DC voltage according to its on / off operation; at least one output filter is coupled to the switching circuit , Each system is used to provide a predetermined output voltage to a load;, at least = switch control circuit, each system uses an output voltage and a reference The voltage u ratio # 乂 generates a pulse width modulation signal to control the on / off operation of the switching circuit; and a reference voltage generator, which couples and provides a reference voltage to each system to make each predetermined output voltage nearly consistent . Connected to the switch control circuit, it is a sub-switch control circuit, and one of the rising slopes of the reference voltage during the start-up period tends to the reference 2 · The power converter voltage generator according to item 1 of the patent application scope includes:, σ The voltage of a linear voltage generating circuit; used to generate a rising slope characteristic -Diode 'which has -anode to receive one and to receive the voltage with -rising slope characteristics or, the state of -to receive the remote on / off signal 200412708 6. Applying for a patent range voltage, and limiting the DC high voltage with a rising slope or the DC high voltage with a fixed level according to a predetermined voltage to generate a first-generation voltage; and referring to a second reference voltage generating circuit, It is based on the status of the remote on / off and Fan No. to receive the voltage with a rising slope characteristic or represents ^ one of the status of the remote on / off fast No. is on and has a fixed level of the DC ancient voltage. And when the second reference voltage generating circuit receives the voltage with a rising slope characteristic, the voltage with a rising slope characteristic is delayed for a short time to start and the slope is increased to generate a second voltage. A special 3 · β power converter as described in item 2 of the scope of patent application, wherein the reference voltage generator further includes a comparator, which compares an inrush current limit induced voltage with a fixed voltage, and responds accordingly The comparison generates a switch control signal. 4. The power converter according to item 3 of the scope of patent application, wherein the linear voltage generating circuit further includes: a current source; a capacitor having one end coupled to a ground; a switch coupled to the current Between the source and the capacitor, it is turned on / off in response to the switch control signal, and the current source charges the capacitor when it is turned off, and charges the capacitor when it is turned on. A linear voltage having a rising slope characteristic; and a voltage follower for coupling the linear voltage having a rising slope characteristic to an output node thereof. Page 21 200412708 VI. Patent application scope 5 • The reference voltage generating circuit described in item 4 of the patent application scope generates a first reference voltage from a peak voltage of the linear voltage including a voltage limiter rate characteristic. 6 · If the patent application scope item No. 4 reference voltage generating circuit includes: a voltage subtractor for subtracting the specific voltage or the DC with a fixed level to generate a reduced rising linear electrical first quadrant cut A wave filter for removing components other than the first quadrant to generate a rising linear voltage; an amplifier for amplifying a voltage having a polarity to increase a slope thereof; and a voltage limiter for limiting the magnification voltage A peak voltage is at a predetermined reference voltage signal. 7 · If the scope of the patent application item 1 control circuit further includes: An error amplifier, which compares the voltage and outputs a pulse and a drive circuit, which drives the switch circuit to turn on. 8 · If the scope of the patent application is 7 Item power converter, wherein the first one is limited to have a rising slope voltage at a predetermined voltage level, the power converter, wherein the first high slope characteristic of the line high voltage and a fixed voltage phase Voltage or DC voltage; the generation of the reduced rising linear voltage, which has a time delay effect, and the time delay effect of the rising line voltage generated by the rising line device to generate the second-mentioned power converter, The switch closes part of the width according to the pulse. One of the output voltage and a reference electrical transformer signal; and a width power converter of a pulse width modulation signal, in which the driver is 200412708 VI. Application for patent scope-The circuit is a bipolar junction transistor (β j τ). 9. A reference voltage generator for a power converter, comprising: a linear voltage generating circuit for generating a characteristic voltage with a rising slope; ¥ a reference voltage generating circuit for limiting based on a predetermined voltage The voltage having a rising slope characteristic generates a first reference voltage · and a second reference voltage generating circuit for starting the voltage with a rising slope characteristic after a short period of time and increasing the slope of the voltage, A second reference voltage is generated. 10. The reference voltage generator as described in item 9 of the scope of patent application, further comprising a comparator, which compares an inrush current limit induced voltage with a fixed voltage, and generates a switch control signal in response to the comparison. 11. The reference voltage generator according to item 10 of the scope of patent application, wherein the linear voltage generating circuit further includes: a current source; a capacitor having one end coupled to i and a ground terminal; a switch coupled to Between the current source and the capacitor, it is turned on / off in response to a switch control signal, and the current source charges the capacitor when turned off, and charges the capacitor when turned on, and is established on a circuit node A linear voltage having a rising slope characteristic; and a voltage follower for coupling the linear voltage having a rising slope characteristic to an output node thereof. 12. The reference voltage generator according to item 丨 丨 in the scope of patent application, wherein 200412708 VI. Patent application voltage limiter, which limits the linear voltage level of the first reference voltage generating circuit with a peak voltage of _ peak voltage to a predetermined voltage, and generates a first reference voltage stag. 13. The reference voltage generator as described in item 12 of the scope of patent application, wherein the first reference voltage generating circuit includes: a linear slope of a rising slope characteristic, a decreasing rising linear voltage; a generation of the decreasing rising linear voltage A voltage subtractor with a time delay effect for subtracting a fixed voltage from a fixed voltage to generate a first quadrant chopper for removing components outside the first quadrant to produce a rising linear voltage ; The amplified rising line voltage level generated by the device, and generating the second amplifier to amplify the rising linear voltage with a time delay effect to increase its slope; and a voltage limiter, which limits the A peak voltage at a predetermined reference voltage signal Page 24