TW591871B - 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

591871 V. Description of the invention (1) The technical field to which the invention belongs The present invention relates to a type of power converter 'More specifically, the present invention relates to a start-up overshoot inhibition technology for a power converter 〇 Prior technology month See more in the figure. It is one of the conventional synchronous rectifier power converters. It is not intended. As shown in the first figure, a conventional synchronous rectifier power converter usually includes a switching control circuit 101, a magnetic saturation amplifier 102, a switching circuit 103, an output filter 104, and a resistive voltage branch. Voltage regulator 105 and reference voltage generator 106. The magnetic saturation amplifier (magnet ic ampl if ier) 102 amplifies the parent current voltage VAC induced by the secondary winding end of a transformer n in a magnetically coupled manner (magnetic C0Upiing), and the amplified AC voltage is borrowed It is converted into a DC voltage by the on / off operation of the switching circuit 〇 03. The generated DC voltage is rectified and smoothed by an output filter (〇utpu1; filter) 104 composed of an inductor la and a capacitor CA, and an output voltage v0 is provided to a load (not shown). . In addition, the output voltage vo returns a part of the output voltage (fracti〇nai 〇utpUt v〇itage) Vs to a switch control through a resistive voltage divider (resistive voltage divider) 105 composed of resistors RA and ⑽. Circuit 101. Switch control circuit (switch contrC) 1 ci rcu it) 1 0 1 Uses an internal comparator (not shown in the figure for simplicity) to combine part of the output voltage VS with a reference voltage generator 106 One of the reference voltages provided

Page 6 591871 V. Description of the invention (2)

Vref is compared, and a pulse width modulation signal (PWM signal) is generated accordingly. One of the internal drive circuits of the switch control circuit 100 (which is usually completed by a transistor) drives the switch circuit based on one of the width of the pulse width modulation signal, and turns on / off to control the switching task of the switch circuit 103. Cycle (switching duty cycle), and then simultaneously stabilize the size of the output voltage 俾 to complete synchronous rectification. On the other hand, an internal management circuit

circuit, which is not shown in the figure) will send a remote ON / OFF signal to “provide the output voltage to a remote powered device, such as a motherboard or hard disk, etc.” General use Power converters in power supply systems usually provide multiple output voltages with a predetermined voltage level, such as m3V. Each output voltage is provided to more than 5 ge. Multiple electronic devices that can operate at this voltage. As shown in the second figure (a), the first output voltage climbs to a stable voltage level (such as 5 V) with a fixed rising slope within a suitable starting period (0-tl), at which time the power is switched The device is a starter ^ ^^^ i ^ t, ^ raUstart.up time 〇r set.u / t; J) 73 Second power: from the input terminal to the power supply until its output voltage rises to

A second output voltage vout2 ^ B 2) that is directly activated at the gate rnH climbs to a level of ___ f ”with a fixed rising slope (such as 3,), and the second output voltage is rising and The slope of the second output voltage vout2 is in the rising phase: after the voltages are stabilized respectively, the power converter outputs two different levels of stable DC voltages to the other negative 591871. 5. Description of the invention (3) It enters normal weighted operation. However, the load of the power converter is generally a load element, so when the power is switched to operate, the load current of the load also changes dynamically A, instead of two = unchanged, Therefore, it may happen that the slope of the output voltage in the rising part may be too large due to the instantaneous rise in electricity and the sudden rise in power when the power converter turns out to exceed the set value. As shown in the figure (b), the first output voltage ¥ 〇111; 1 is affected by its corresponding value, and an excessive voltage is turned on instantly, which causes electricity; However, at the same time, the second output voltage "Slave 2" keeps the same rate, so that during the start-up period of the power converter, the instantaneous voltage value of the first output voltage ¥ 〇111: 1 and 〃 = the output voltage. The difference between the instantaneous voltage values of VQut2 exceeds its stable voltage. [Distance, for example, 5V_3.3v = 1.7v, resulting in the power converter's output must be firm. The voltage that the overloaded component can withstand and cause malfunction, resulting in This kind of phenomenon in which the secondary system malfunctions because the output voltage rises rapidly during the start-up period is called start-up overshoot (overshoot 〇r set-up 〇versh 〇t). ~ So what is needed is A startup overshoot prohibition technology for a power converter is proposed to avoid the problem of startup overshoot during startup of the power converter to ensure the normal operation of the system. SUMMARY OF THE INVENTION A more general aspect of the present invention is a power conversion End of device

591871 V. Description of the invention (4) ^ i It includes at least one magnetic saturation amplifier, each of which is magnetically coupled, one of the devices is wound by an alternating voltage, and the alternating current is amplified, to two or more switch secrets, Coupled to the magnetic saturation amplifier, each system converts the amplified AC voltage into a DC voltage due to its on / off operation. At least one wheel-out filter is coupled to the switching circuit. A load, at least one switching control circuit, = system variable gas = compare with a reference voltage to generate -pulse width modulation t signal to control the on / off operation of the switching circuit, and a meter test voltage production ^ ' Lightly connected to the switch control circuit, which respectively provides a reference voltage to the mother and a switch control circuit, and the person who occupies the -M ~ [μ output voltage is within-during the start-up period; == a predetermined Power generation! Meaning :: Production = reference voltage generator includes-linear voltage production test voltage generation conversion, use: ί; sexual voltage '-the first-reference rate characteristics of the I ;, limit the rise of the slope test voltage generation ㈣' to Make a special one == reference electric migration. η and the slope of the power is added to produce a second, invention = the previous description and the advantages and examples of the present invention are combined with the following illustrations in detail to obtain a more in-depth "simple schematic illustrations" A picture is a legend showing a circuit of a conventional power converter according to-591871 V. Description of the invention (5) The second picture (a) is a waveform diagram showing the output voltage of a conventional power converter with a plurality of predetermined DC voltage outputs ; The second figure (b) is a waveform diagram showing a startup overshoot phenomenon of the output voltage of the power converter with a plurality of predetermined DC voltage outputs; the third figure is a schematic circuit diagram of one of the power converters of the present invention; the fourth The figure shows a circuit diagram of a switching control circuit of the power converter of the present invention; the fifth diagram shows a circuit diagram of a reference signal generator of the power converter of the present invention; the sixth diagram shows the power converter of the present invention Refer to the voltage waveform diagrams of the respective internal circuit nodes of the signal generator; and ° The seventh diagram shows the inrush current limit induced voltage ', the remote on / off signal Voltage waveform diagrams of the first reference voltage and the second reference voltage. Element symbol description ... 1 0 1 Switch control circuit 102 Magnetic saturation amplifier 1 0 3 Switch circuit 104 Output filter 105 Resistive voltage divider 106 Reference voltage generator 200,201 circuit parts 2 0 2, 2 0 3 switch control circuit 204, 205 magnetic saturation amplifier

Page 10 591871 V. Description of the invention (6) 2 0 6, 2 0 7 Switching circuit 2 0 8, 2 0 9 Output filter 210, 211 Resistive voltage divider 212 Reference voltage generator 213 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 306 Voltage Limiter 307 Fixed Voltage 308 Fixed Voltage 3 0 9 Voltage Subtractor 3 1 0 First Quadrant Chopper 3 11 Amplifier 3 1 2 Voltage Limiter 315 Linear Voltage Generation Circuit with Rising Slope 316 First Reference Voltage Generation Block 317 Second Reference Voltage Generation Block Implementation Method One circuit diagram of the power converter of the present invention is shown in the third Illustration. The power converter of the present invention is configured to provide a large number of reservations.

591871 V. Description of the output voltage of invention (7). In this preferred embodiment, voltage is used as an example, but the same principle and application can further provide more than two predetermined output voltages. The power supply shown in the third figure is a circuit section (section) 200, 20 1 'Each circuit section is a set of < set to generate a predetermined output voltage. The circuit component 200 includes a magnetically saturated g 5 and a large device 204, which are magnetically coupled to amplify the AC voltage induced on the transformer _t = a ^ winding end, and switch the electric ^ On < 0 < 0 > operation of 206 is converted to a DC voltage. The generated DC voltage is rectified and smoothed by an output filter 20 composed of an inductor L1 and a capacitor C1, and a first output voltage v0utl is generated and provided to two loads (not shown). Similarly, the circuit component 201 includes a magnetic saturation amplifier 2 0 5 'which amplifies the parent current voltage induced on the auxiliary winding of a transformer τ 丨 by magnetic coupling' and passes the switching circuit 2 〇7 The on / off operation is converted into a DC voltage. The generated DC voltage is rectified and smoothed by an output filter 20 composed of an inductor L2 and a capacitor C2, and a second output voltage v0ut2 is generated and provided to a load (not shown). In addition, the first output voltage Vout 1 further returns a portion of the output voltage VS1 to a switch control circuit 202 via a resistive voltage divider 21 composed of resistors ri and R2. The switch control circuit 202 uses an internal comparator (not shown in the figure for simplicity) to compare a portion of the output voltage VS1 with a first reference voltage Vrefl provided by a reference voltage generator 212. And generate a pulse-width modulation signal (PWM signal) accordingly. One of the switching control circuits 202

Page 591871 (which is usually completed by a transistor) drives the switching circuit 20 6 on / off according to one of the pulse width modulation signals, thereby controlling the switching duty cycle of the switching circuit 206 (swHching duty cycle), Furthermore, at the same time, the size of the first output voltage 乂 11111 is simultaneously used to complete the synchronous rectification. In the same way, the description of the invention (8), the same output voltage 2 returns a part of the output voltage m2 to a switch control circuit 203 via a resistive voltage divider 211 composed of resistors r3 and R4. The switch control circuit 203 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 generator 212, one of the second reference voltage Vref2 Make a comparison and generate a pulse width " weekly signal (pUlse-width modulation signal, PWM signal) accordingly. A driving circuit (which is usually completed by a transistor) inside the switching control circuit 203 drives the switching circuit 207 to turn on / off according to one of the pulse width modulation signals, thereby controlling the switching task of the switching circuit go? 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 (which is not shown in the figure)-will send a remote ON / OFF signal to provide the output voltage Voutl or Vout2 to the far-end power receiving Devices such as motherboards or hard drives, etc. The fourth figure shows a schematic diagram of one of the switch control circuits 002, and the circuit operation principle will be described as follows. It should be noted that the switch control circuit 02 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 591871

The switching control circuit 202 includes an error amplifier 213, which has an inverting input terminal to receive a part of the output voltage vsi provided by the voltage divider 21, and has a non-inverting input terminal (n0n- (inverting terminal) receives one of the first reference voltages Vrefl provided by the reference voltage comparator 212. A part of the output voltage vsi provided by the voltage divider 210 is compared with a first reference voltage Vrefl provided by the reference voltage comparator 212 via the error amplifier 213, and a pulse width modulation signal is generated and input to a driving circuit 2 1 4. The better one is constructed by a bipolar junction 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 overshoot prohibition is to set a time delay & adjust the rise time of the reference voltage provided to the switching control circuit for adjusting the output voltage when the power converter starts. The slope, thereby forcing a rising slope of the output voltage during the startup period to change correspondingly, that is, the rising slopes of the respective output voltages during the startup time are brought close to the same, which can effectively avoid the problem of startup overshoot. Peak 0 • Please refer to the fifth figure. According to a preferred embodiment of the present invention, a circuit structure of a reference voltage generator 212 includes a comparator 301, which has an inverting input terminal N1 that receives the second voltage from the transformer 2 Inrush current limit sense

Bsense, whose voltage waveform is shown in Figure 7, and a non-inverting input receive-fixed voltage 307. The comparator 301 compares the inrush current limiting induction voltage 591871. V. Description of the invention (ίο) The voltage Bsense is compared with the fixed voltage 307, and a switching control signal VSW is generated according to the comparison result to a linear voltage with a rising slope. Gate 303 of circuit 315. A linear voltage generating circuit 315 with a rising slope = switches 303, 304, a current source 302, a capacitor, and a voltage follower t Cvol tage f 〇1 l0we] r) 305. The switch 303 switches its on / off state in response to one of the switch control signals and VSW, and the capacitor has one end to a ground. When the switch 3 is in the off state, the current source 302 is electrically charged and the energy is stored in the capacitor. When the switch 303 is located at 3n. Β '电 谷 CS is discharged to the voltage follower via the circuit node N2, ^ $ inverting input terminal, so the voltage on one of the non-inverting input terminals of the voltage follower 305 is It belongs to the linear voltage VCS with a rising slope, and its voltage waveform is shown in the sixth figure. It is located at the circuit node N2 and is located at the right of the north office. The voltage is coupled to the circuit node N3 via a linear voltage VCS following the voltage of the coupled slope 3 (^ ,, ^^ rising slope), and then the node P Θ St l 1. Second = linear voltage VCS is then applied to the first-test voltage generated-circuit node and the second / to / ^ test voltage generation block 316 internal circuit node N4 respectively in the transmission block 317. " As shown in Heart 2 of a lifetime, the reference voltage generates an on / off signal of a preferred embodiment of the present invention, "and a cathode, A is connected; Receive-a circuit node N5 inside the remote block 316: j is connected with a reference The voltage generation square system is shown in the seventh figure. As shown in the seventh figure, the voltage wave port of the on / off signal at the end of the hard end is shown in the seventh figure.

Page 15 591871 V. Description of the invention (11) When in the ON state, its actual voltage level is a low voltage, which causes the diode to be turned off (tuirn off) and the first reference voltage Vrefl and the second reference The voltage Vref2 is determined by a linear voltage yes with a rising slope. When the remote on / off signal is in the OFF 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 and off flood numbers and the linear voltage vcs of the rising slope is smaller than the threshold voltage of the diode D1 (thresh〇ld value ), The diode D1 is still in the off state, and the first reference voltage Vref i and the first reference voltage Vref2 are also determined by the linear voltage yes with a rising slope. However, the instantaneous voltage value difference between the voltage level of the on / off signal at the transport end and the linear voltage vcs of the rising slope is greater than the threshold value of the diode D1, and the diode M will be turned on, and it is assumed that the diode The body D1 is an ideal diode, which means that it does not generate any voltage drop at its terminals. The first reference voltage generates a circuit node N5 inside the block 3 16 and the second reference voltage generates the block 3 17 inside. A circuit node M will receive a high electrical θ voltage represented by the remote on / off signal during the off (0FF) period, and the first reference voltage Vrefl and the second reference voltage Vref2 are derived from this high voltage. Decide. Therefore, in the first reference voltage generating block 316, when the remote on / off signal is within the ON period, the node N5 receives a linear voltage vcs with a rising slope, which passes through a voltage limiter (voltage limitei〇3 ^ 6 and a peak voltage (peak v〇itage) is limited to 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 591871 V. Description of the invention (12) Part of the opening / closing flood 5 tiger 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 starting voltage of the diode D1 ^ thi ^ shold vaiue), the node N5 receives the south voltage of the remote on / off signal. Therefore, the first reference voltage Vrefl formed will be a DC high voltage with a fixed level, and its voltage waveform is displayed during the off period of the remote on / off signal. Similarly, in 'in the second reference voltage generating block 317, when the remote on / off signal is in the ON period, the linear voltage VCS with a rising slope is faced to the circuit node n 4' and passed through a voltage The subtractor 3 009 subtracts it from a fixed voltage 3 008 to obtain a reduced voltage VREDUCED. The voltage waveform is shown in the sixth figure. The reduced voltage VREDUCED is further filtered by the first quadrant chopper 31 0 to filter out components outside its first quadrant to obtain a cut-off voltage VCH0PPED with a time delay effect. The voltage waveform is shown in Figure 6. The cut-off voltage VCH0ppED is further amplified by amplifying state 3 11 to obtain an amplified voltage VAMP ′ which is one of the rising slopes. The voltage waveform is shown in the sixth figure. Finally, the amplified voltage VAMP is limited by a voltage limiter 3 1 2 to a peak voltage at a fixed voltage level, and the formed voltage is regarded as a second reference voltage Vref 2 ', and its voltage waveform is also displayed on Sixth figure. On the other hand, when the remote on / off signal is within the OFF period, the high voltage represented by the remote on / off signal will be coupled to the circuit node! ^ 4. This DC high voltage with a fixed level will then pass through the voltage subtractor 3009 to make it a fixed voltage 3 08

Page 17 591871 V. Description of the invention (13) Subtract and then perform% Gu # 丄 on i via amplifier 3 1 1 to amplify the pair to produce a second reference voltage Vref2. During this period, the voltage waveform of the gate ^ belt # 海 千 # g 1 @second reference voltage Vref 2 is not within the corresponding time zone of the seventh figure. From the above 5 Erming and each Leiyou # @ μ ^ — ffl * ^ ΗΗ ^ ^ ^ ^ ^ voltage waveform of a point of the circuit can be found, using the startup overshoot of the present invention-M β P β M t technology to confirm Continuously adjust the time delay and rising slope of the reference voltage, 7 a. T /-lra .. The yarn is as fine as M such as ΛΛ L, which forces the output voltage of each wheel to be nearly the same in the power supply, and can eliminate the multiple output voltage. Under the condition of the pad, the hair can be activated to overshoot. Even if the present invention has been described above, σΊ ^ L ^ ^ ^ # # t 4 of the case of bismuth can be described in detail. Those who are skilled in art are thought to be jealous of you. ^.. T ^ m The clever postscript modification, but it is not as good as those who want to protect the patent application.

Page 591871 Brief description of the diagram The first diagram is a schematic diagram showing a circuit diagram of a conventional power converter; the first diagram (3 *) shows a conventionally used power converter with a plurality of predetermined DC voltage outputs The output voltage waveform diagram; the second diagram (b) is a waveform diagram showing that the output voltage of the power converter with a plurality of predetermined DC voltage outputs starts to overshoot; the third diagram is one of the power converters of the present invention Circuit diagram · The fourth diagram shows the private day and night, Xi Lei, and shield wire β " _ φ ^ & Electricity of the Moon, the original conversion benefit of the switch control circuit is not the wrong way of thinking; the fifth diagram Shows a schematic circuit diagram of one of the power converters of the present invention; the sixth diagram of the house ecology can show the voltage waveform diagrams of the respective internal circuit circuit nodes of the power converter of the present invention; the seventh figure shows the intrusion Voltage limit diagram of the current limit induction number, the first reference voltage, and the first reference voltage when the first loss of Lei Jixi's heart is turned on / off.

Page 19

Claims (1)

591871 VI. Application for Patent Scope 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 a transformer and a winding on an AC voltage, and amplifies The AC voltage, · D ㈤ ^ one less switching circuit, is coupled to the magnetic saturation amplifier, and each of them performs an eighth / off operation to convert the amplified AC voltage into a DC voltage ^ to >, an output filter, Each switch is coupled to the switch circuit to provide a predetermined output voltage to a load. At least: the switch control circuit 4 each generates 3 pulses per output voltage and 3 / V to generate a pulse. Width modulation signal to control the on / off operation of the switching circuit; and I shall not be provided for: ί ί Generating 'coupled to the switch control circuit 4' Its system = a predetermined output voltage during the start-up period A linear voltage generated by a rising ramp voltage generates electricity $, which is used to generate electricity with a rising slope characteristic. A three-body body has an anode to receive a remote on / off signal, and a cathode ^ receives the The voltage of the rising slope characteristic, & μ reference voltage generating circuit, which is based on the remote on / off signal = 1 state to receive the voltage with a rising slope characteristic or represents the on / off signal of the end A state with a fixed level of high DC Page 20 591871 6. Apply for a patent range voltage and limit the voltage or the DC voltage with a fixed level according to a predetermined voltage; and generate the first reference voltage and the reference voltage generation circuit. A skin state is divided into females L according to the status of the remote on / off signal to receive the remote on / off signal with a rising slope characteristic. The & Straight 1 table / Hai 2 emperor and when the second reference voltage generating circuit receives the voltage with two characteristics n _ 'Make the with-rising slope characteristics start after a short time and increase its slope While = voltage.土 一一 Ref 3 · The power converter described in item 2 of the scope of patent application, wherein the 夂 voltage generator further includes a comparator which compares an inrush current limit ▲ the voltage to be compared with a fixed voltage, and A switch ^ signal should be generated as a result of the comparison. 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 Between the current source and the capacitor, it is turned on / off due to the switch control signal, and the current source charges the capacitor when it is turned off, and the capacitor is charged when it is turned on. Establishing a linear voltage with a rising slope characteristic; and a voltage follower for coupling a spirit voltage having a rising slope characteristic to an output node thereof. The line Page 21 W1871 5. The power converter according to item 4 of the scope of patent application, wherein the first reference voltage generating circuit includes a voltage limiter that limits a peak voltage of a linear voltage having a rising slope characteristic to a predetermined Voltage level to generate a first reference voltage. 6 · The power converter according to item 4 of the scope of patent application, wherein the second reference voltage generating circuit includes ·· 〃 a A voltage subtractor for generating a reduced rising linear voltage from the voltage or the DC with a fixed level-a first quadrant chopper for removing components outside the quadrant to produce a linear voltage; The linear electrical high voltage of the rising slope characteristic is subtracted from a fixed voltage, or a DC voltage; the first generation of the reduced rising linear voltage has a time delay effect rising-amplifier for amplifying a time delay effect Ten voltages on the rising line to increase a slope thereof; and a voltage limiter that limits a peak voltage of one of the amplified rising line voltages generated by the amplifier to a predetermined voltage level to generate the second reference voltage Signal. t & The power converter according to item 1 of the scope of patent application, wherein the switch control circuit further includes: -An error amplifier which compares one of the output voltages with a reference voltage f 'and outputs a pulse width modulation signal; and a driving circuit' which drives 8 based on the width of one of the pulse width modulation signals Turn on or off the main circuit of the switch. • The power converter according to item 7 of the scope of patent application, wherein the driver Page 591 871 The circuit is a bipolar junction transistor (BJT). L A reference voltage generator for a power converter, which includes: a β linear voltage generating circuit to generate a reference voltage generating circuit having a rising slope characteristic; a reference voltage generating circuit to limit a rising voltage according to a predetermined voltage; The voltage of the slope characteristic generates a first reference voltage · and a second reference voltage generating circuit for causing the voltage with a rising slope characteristic to start after a short period of time and increase the slope of the voltage to produce A second reference voltage. 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. η. The reference voltage generator as described in item 10 of the patent application scope, wherein the linear voltage generating circuit further comprises: a current source; a capacitor having a terminal connected to a ground terminal; a switch coupled to the 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 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. 12. The reference voltage generator as described in item 11 of the scope of patent application, wherein 591871 6. Scope of patent application The first reference voltage generating circuit includes a voltage limiter, which limits a peak voltage of a linear voltage having a rising slope characteristic to a predetermined voltage level, and generates a first reference Electric 麈. 13. The reference voltage generator according to item 12 of the scope of patent application, wherein the second reference voltage generating circuit includes: a voltage subtractor for phase-changing the linear voltage with a rising voltage characteristic and a fixed voltage Subtraction to generate a reduced rising linear voltage; a first quadrant chopper for removing components other than the first quadrant of the reduced rising linear voltage to generate a rising linear voltage with a time delay effect; An amplifier for amplifying the rising linear voltage with a time delay effect to increase a slope thereof; and a voltage limiter 'which limits a peak voltage of the amplified rising linear voltage generated by the amplifier to a predetermined voltage Level, and the second reference voltage signal is generated. Page 24