TWI361553B - Controller for a switching voltage regulator, method to compensate for variations in a supply voltage level in a voltage regulator, and pwm controller - Google Patents

Description

1361553 IX. Description of the Invention: [Technical Field] The present invention relates to a pulse width modulation (PWM) controller for a switching voltage regulator, and more particularly to a feedforward circuit, The reverse adjustment has an output pulse width with respect to the supply voltage to compensate for variations or transients in the supply voltage. [Prior Art] A general switching galvanic regulator receives a DC (Dc) supply voltage at a first level and an adjusted output voltage at a second level. The second level is above or below the first level. Different power supplies, such as batteries or alternating current (AC) power adapters, can provide a DC supply voltage. Different power supplies can provide different DC supply voltage levels, and the DC supply voltage level of the same power supply can vary with time. In the PWM type switching regulator, the rising or decreasing of the output electrical waste after the adjustment tends to be higher and lower than the increase or decrease of the electric dust supplied by the straight machine: The TM controller that switches the galvanic regulator usually includes a feedback loop, and the 1 feedback loop forces the adjusted output (4) to return to the -level. The rapid change in the voltage of the deficiency; usually for the DC supply is fast enough to prevent the output of the output after the adjustment, the response is often insufficient to exceed or exceed the voltage. The current is supplied to the transient in _. - The feedforward supply is repeatedly changed/compensated, and the slope of the mid-slope wave signal is DC change, which is used to control the pulse width of the PWM output to be biased by the capacitor. 8 "Electric-system" and the power across the capacitor 6 1361553 The voltage cannot be changed instantaneously' thus the pulse width correction has a large delay. For example, the utility PWM ramp generator uses a current source or resistor. Charge the capacitor 'to generate a cross-capacitor crying button, t '·“ ^ the ramp voltage. This ramp-wave lightning pressure is compared with the control from the error amplifier as a system to adjust the pulse width of a pwM output. Since the ramp and voltage (i.e., the voltage across the capacitor) cannot be changed instantaneously when the charging current fluctuates, the chirp voltage cannot be immediately stepped up by u and the transient of the fast supply voltage is corrected. This correction may be the minimum of half a cycle of the ramp voltage and up to several cycles. SUMMARY OF THE INVENTION In the implementation of the radiation, the present invention proposes a pulse width modulation (mail (four) centimeter, PWM) controller, (10) the controller reversely adjusts the error about the supply voltage (four) (or PWM control signal) To quickly compensate for variations or transients in the supply voltage. The PWM (four) device generates at least one output signal, and the output signal drives one or more semiconductor switches in the switching voltage adjustment $ ((10) "coffee voltage regulator". The switching voltage regulator receives the supply voltage 'and generates for the load - the adjusted output voltage (regulated output voltage) e adjusts the output voltage level depending on the supply voltage level and the duty cycle Uutycycle (or pulse width) of the output signal from the PWM controller. The duty cycle of the output signal from the pwM controller is partially The error signal in the feedback loop is controlled. The ability to quickly adjust the error signal in response to transients in the supply voltage helps to maintain - substantially constant adjustment of the output power and + excessive supply due to supply voltage fluctuations or sudden changes (〇versh〇〇t) or undershoot° 96137068 7 1361553 In one embodiment, the PWM controller includes an input configured to receive a feedback signal indicative of an output condition of the switching voltage regulator (eg, an output) Voltage or load current). Error amplifiers (such as transconductance amplifiers) based on comparison The feedback signal and the reference nickname generate an error signal, and the reference signal indicates an output condition required for the switching voltage regulator. The feedforward circuit receives the error signal and receives the indication (the power supply; the supply sensing signal ( For example, 别17 5丨和&1). The feed-in circuit generates an adjusted error signal, and the adjustment error signal has a substantially proportional relationship with the error #, and is substantially inversely proportional to the supply sensing signal. The adjustment error signal is Provided to the first input of the pwM comparator, and a periodic ramp signal is provided! The second input of the PWM comparator is used to generate a pulse width modulated output signal (pulse-width) Modulated output signal). In one embodiment, the feedforward circuit quickly compensates for supply voltage variations (eg, within a half cycle of a periodic ramp signal or within nanoseconds) such that the supply voltage level and pulse width The product of the duty cycle of the modulated output signal is for a particular reference signal to be substantially constant from cycle to cycle. In one embodiment, the feedforward circuit includes voltage control. A current source (v〇ltage-controlled current s〇urce), a voltage control current shift current (〇 set current current , , , , , , , 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬 仏唬The voltage is controlled by the current source by coupling a resistor between the supply voltage and the current mirror circuit. The flow mirror circuit conducts the offset current and is coupled to the output of the error amplifier and the power supply 96137068. 1361553 The summing resistor between the outputs of the mirror circuit (summingresist〇d also conducts the offset current to generate the offset voltage (〇ffset voUage). In the embodiment, the summing resistor has a first end that is coupled to the output of the error amplifier, and a second end that is coupled to the first input of the P· comparator. The error signal at the output of the error amplifier is effectively combined (or summed) with the offset voltage across the summing resistor to produce an adjustment error signal at the second pass of the summing resistor. In one embodiment, the adjustment error signal is inversely varied with respect to the power supply sense signal to maintain a substantially constant adjusted output voltage within a predetermined range ' of the supply voltage level. In another embodiment, the feedforward circuit includes a linear transiaxis circuit (eg, a plurality of transistors arranged in a linear transconductance configuration) to track the supply voltage and respond to transients in the supply voltage. Adjust the error signal. The linear transconductance circuit conducts at least a first current signal, a second current signal, and a third current signal. The product of the first current signal and the second current signal and the third current signal is substantially abbreviated. In an embodiment, the first current signal is obtained from the error signal (eg, using a first voltage current converter (v〇itage-to-current converter)), and the second current signal is obtained from the supply sensing signal The third current signal is used to generate an adjustment error signal (eg, using a voltage-current converter). Thus, the adjustment error signal is directly proportional to the error signal - and is inversely proportional to the supply sense signal. The adjustment error signal generated by the linear transconductance circuit can also quickly reflect fluctuations in the supply voltage (e.g., during the half cycle of the periodic ramp voltage). 96137068 9 1361553 crying (DC to DC &amp; adjustment benefits for DC to DC power conversion; (to - DC p (10) er converter) (for example, squeezing converter), DC to DC power conversion piano and two: change - or rise _ treatment The conversion has an output voltage level that varies with the duty cycle of the pulse width modulation rim (4), and the feedback signal of the = indicates the DC to direct lightning amplification state m. / Lane - the output voltage of the straight/claw power converter In the case of only %, the switching voltage regulator is an inverter (or a DC-to-AC power converter), and the inverter includes an output dust amplitude that varies depending on the duty cycle of the pulse width modulated output signal. : = indicates the current conducted by the load. - The load is cold cathode camp (CCFL) ^. The backlight system of the display (such as liquid crystal display), and the reference signal to the error amplifier The above and other objects, features and advantages of the present invention will become more apparent and understood by the <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; 1 is a block diagram of a switching voltage regulator according to an embodiment of the present invention. The voltage change 5 includes a switching circuit i Q2 configured to receive a supply voltage (vSUPPly) and provide it to the load 104. Output voltage (v.^). The feedback circuit 1 〇6 senses an output condition for generating a feedback signal (FB) of the controller. In one embodiment, the controller 1 uses pwM (puise width) The modulation technique generates one or more PWM drive signals (Vm) to control one or more semiconductor switches in the switching circuit 1〇2. The adjustment of the level or amplitude of the output voltage to the pulse width of the PWM drive signal is 96137068 10 1361553 (or duty cycle) is proportional. This controller 1G0 receives the reference signal (REF) &gt; the reference number indicates the desired level of adjustment of the output voltage or • vibrating field &gt; and a regulator loop includes this PWM circuit, PWM The circuit adjusts the ρ· drive signal according to the difference between the test 5 and the feedback apostrophe. The cycle is used to achieve the desired level or amplitude. The level or amplitude of the output voltage is also adjusted. The supply voltage is proportional. It is desirable to maintain an inverse Product relationship between the supply voltage and the duty cycle of the PWM drive signal to help stabilize the output voltage. As in the embodiment shown in Figure 1, the controller 100 receives the indication. The supply sense signal (supply sensed signa 1 ) is supplied and the duty cycle of the PWM 4 zone motion signal is reversely adjusted in relation to the supply of the sense signal for supplying the power feed forward compensation. In an embodiment, the controller 1 uses an offset compensation technique to quickly or (eg, instantaneous or nanosecond #1) reduce or increase the duty cycle of the PWM drive signal in response to the supply sensing. No. Change. For example, the supply voltage can be provided by a different power source (e.g., battery, battery charging benefit, or AC power adapter). Different power supplies can range from different supply voltage levels (for example, AC power adapters • y are higher voltages than battery outputs). When switching between different power sources when switching the _ = of the voltage regulator action, the supply voltage level can be suddenly changed to =. For example, most electronic devices automatically disconnect their batteries when plugged into an AC power adapter during use, and use an AC power adapter as a power source. 96137068 11 1361553 In addition, this supply voltage can vary due to β. U for other reasons (such as noise or battery discharge) and ▲ offset compensation technology allows the controller (10) to respond quickly to the instantaneous change in the supply voltage, thus reducing the size of the large |, + + 5 weeks output of the output voltage Overvoltage: In other words, the offset compensation technique maintains an approximately constant product for the supply voltage level and the PWM drive signal to reduce the excess and undershoot of the regulated output voltage. In another embodiment, the controller 100 uses a linear transconductance circuit to charge the product to a nearly constant product of the supply voltage level and the duty cycle of the PWM drive signal Vm to maintain A substantially constant adjustment of the output voltage. Both offset compensation techniques and linear transconductance circuits can also be used to correct for gradual changes in the supply (for example, the battery is slowly discharged during use). The offset compensation technique and the linear transconductance path are described in further detail below. The switching dust adjuster of Figure 1 can be a DC-to-DC power converter (DC-to-DC erconverter) or a DC-to-AC power converter (such as an inverter). In some applications, the inverter is used in a cold cathode fIU0rescent lamp (CCFL) powered in a backlight system and maintained between the supply voltage Vsupply and the duty cycle of the PWM drive signal: reciprocal product The tether 'to ensure that the light intensity is approximately constant over a range of supply electrogrind levels (or applied battery dust). In addition, the reciprocal product relationship is maintained in response to transients (or rapid changes) in the supply voltage t, avoiding unwanted lamp flicker. 96137068 12 Figure M and 2β 5 children Ming various DC to DC power conversion crying * * KM ^ Specifically, Figure 2A gives - text supply. Palladium case. l &gt; 1 transform - Gan buck converter, and Figure 2 shows that the type of DC-DC converter (for example, combined buck-boost converter) can also use the advantages of the present invention Provide one week...=Excellent, "Refer to Figure 2A' buck converter with the corresponding voltage (Vsupply), the lower the imitation i, the ten electric h, and the straight supply to the low level. In the only example, the buck converter package L ^ Off (or high side switch (hlgh_Side switch)) 204: A semiconductor switch 2〇0 is coupled to the DC supply voltage and the second end of the inductor output inductor 204 provides adjustment of the DC output. ) 206 and output resistor (Rl〇ad) = 8 parallel across the light DC output voltage to represent - load (for example, f processor). Output capacitors can also represent chopper capacitors to reduce &gt; adjust DC The output of the wish is chopping. The diode (for example, a sweet bit (cl_cle) or a flywheel diode (free_wheeHng di〇de)) 2〇2 is connected to the first end of the inductor 204 and the reference end ( For example, grounding. The diode 202 can be alternately replaced with a second semiconductor switch (or synchronous switch) The feedback circuit 216 senses the adjusted DC output voltage and generates a feedback voltage (Vfb) of the controller 210. The PWM controller 2iq also receives the reference voltage (V-, reference (4) Vref indicates the desired level of the DC output voltage. The PWM controller 210 generates a variable pulse width drive signal (v_) to control the high side switch 200. The level of the regulated DC output voltage depends on the pulse width (or duty cycle) of the drive signal and the DC supply voltage level. The controller 210 changes 96137068 13 1361553 to drive the pulse width of the k-number based on the difference between the feedback battery and the reference voltage. In addition, the controller 21 receives a supply sensing signal indicating the DC supply voltage level. And can quickly adjust the pulse width of the drive signal to compensate; the flow supply: the voltage level changes. Figure 2Β has a similar component as Figure 2, but the components are arranged differently to form an adjustment a DC output voltage boost converter, the adjusted DC output voltage has a higher level than a DC power supply voltage. For example, the input inductor 218 is coupled to a DC supply voltage and a medium Between the intermediate nodes, the semiconductor switch 212 is engaged between the intermediate node and the grounding. The isolation diode 214 has an anode coupled to the intermediate node, and a coupling coupled to the regulated DC output voltage. The cathode. The boost converter's pwM controller 22 generates a variable pulse width drive signal (VpwM〇 to drive the semiconductor switch 212 and operates in a similar manner to the PWM controller 21 of the buck converter to compensate for the DC Changes in supply voltage. 3A and 3B illustrate an example of a converter top topology for driving the fluorescent lamp 312. In particular, FIG. 3A illustrates an inverter using two semiconductor switches 300, 302 in a push-pull topology; and FIG. 3B illustrates a full-bridge topology. Four inverters of semiconductor switches 300, 301, 302, 303 - are used. Other commutations having the same or different number of semiconductor switches (e.g., half bridges (ha 1 f - br i dge )) may also take advantage of the advantages of the present invention. For example, the PWM controllers 308, 318 of Figures 3A and 3B both receive a supply sense signal indicative of the supply voltage level and can be quickly adjusted with 96137068 14 Ϊ 361553 = conductor switches 300, 3 (Π, 3〇2, 303 The drive signal is associated with a '乍 cycle' to compensate for variations in the supply voltage. In an embodiment, an inverter is used to power the fluorescent light in the backlight system 'eg CCFLs', and the PWM circuit is a commutation The portion 77 of the controller chip in some applications 'to the input power supply to the converter can be changed quickly and arbitrarily in time. For example, when the AC power adapter was "hot plugged", the input voltage was seen in the laptop, and it was worried. The DC output voltage of the AC power adapter is generally higher than the voltage and voltage to facilitate battery recharging and to quickly increase the supply rail for the CCFL. In some applications, the supply rail is between 10-15 volts when operating on a battery and 18-24 volts on an AC power adapter. When the AC power adapter is initially inserted, the power rail jumps from the battery voltage to the AC power adapter output voltage in a fast transient. 4 is a simplified block diagram of an embodiment of a PWM controller having an inverse feedforward compensator 400 that reacts rapidly to supply voltage transients by inversely adjusting the error signal. In one embodiment, the pWM controller includes a transconductance amplifier (or error amplifier) 402 and a PWM comparator 404. The transconductance amplifier 402 receives a feedback signal (FB) indicating a load condition (eg, lamp current sensing in a backlight* source application), and a reference to receive an indication-desired or reference load condition (eg, a lamp adjustment voltage) Signal (REF). Transconductance amplifier 402 produces an error signal based on the difference between the feedback signal and the reference signal. Capacitor 406 can be coupled to the output of transconductance amplifier 402 to generate an error voltage based on the current output of the transconductance amplifier. 96137068 15 1361553 When the PWM controller is implemented as an integrated circuit (IC) chip, the capacitor 4〇6 is typically coupled to one of the package pins of the ic chip (such as the pin labeled EA-OUT). External components. The error voltage is supplied to the inverse feedforward compensator. The inverse feedforward compensation boundary 400 also receives a power sensing signal (VBAT乂) indicating one of the supply voltage levels (or battery voltages) and generates an adjustment error signal (eg, Vad) for use in one of the PWM comparators 404. The PWM output (PWM-OUT) maintains an approximately constant product of a supply voltage level and a duty cycle (or pulse width). For example, the PWM comparator 404 adjusts the error signal with a sawtooth oscillator (not shown) The resulting ramp signal (Vramp) is compared to produce a PWM output. In one embodiment, the duty cycle of the PWM output is reduced (or increased) by a slight increase (or decrease) in the supply voltage by a slightly equal percentage. The output voltage is stably adjusted to maintain one of the reduced excess (〇versh〇〇t) and undershoot of the switching voltage regulator. The output is supplied to a driving circuit (not shown) to generate one or more Drive the h number to control one or more semiconductor switches (such as field effect transistors) for switching the voltage regulator. The inverse feedforward compensator 400 can use the offset technique (offs Et techniques) or linear translinear principles to inversely adjust the pulse width of the PWM output associated with the change in supply voltage and provide transients for supply voltage to provide substantially instantaneous compensation. Figure 5 illustrates an error signal How to reverse-adjust a supply voltage (or battery voltage) from a range of 7V to 28V. A sawtooth waveform is shown for reference and represents a 96137068 16 1361553 range on the input of comparator 404 in FIG. The ramp signal from 0.5V to 4.0V. It is also possible for the rake wave signal or the peak to peak voltages with other amplitudes to be “over-changed” in the following equations. The t U 400 - output adjustment error signal has an initial voltage (eg, νι) at the first supply voltage (eg 'VBAT1 = 10V'). The deer voltage is changed to the new level (eg 'VBAT2 = 19V) , tune; error: The signal changes to the second voltage of the relationship (for example, V2): l^2 = 0.5F + (n-0.5F)x

VBATI VBAT2 Table 1 shows an example calculation for two different supply voltage levels to further illustrate how the adjustment error signal and PWM output duty cycle (or pulse width) decrease with increasing supply voltage to maintain supply voltage A substantially constant product of the ρ· output duty cycle. Table 1 VBATI = 7V ...... VBAT2 = 19V -- VI = 4. 0V η ^ , , 4.0V - 0.SV Dutycycle_l = —x 1〇〇= 1〇〇〇/0 VBAT\ X Dutycycle_\ = 7F χ 1 〇〇〇/〇= η V2 = 0.5F ^-{AX)V — Q,SV)x^~ == 1.789K &quot; 1.789F-0.5F Dutycycle_2 = —〇-^_〇^ x 100 = 36.8% KR4:T2 x £&gt;«Qingyi-2 = 19F x 36.8% = 7 Figure 6 illustrates one of the pWM controllers with an inverse feedforward compensation circuit implementing an 'inverse feedforward compensation circuit to generate a supply voltage based offset The signal is combined with an offset 彳§ number and an error signal to inversely adjust one of the PWM outputs associated with the supply voltage. In one embodiment, the inverse feedforward compensation circuit includes a voltage controlled current source 96137068 17 1361553 (voltage-controlled-current-source, VCCS), and the voltage controlled current source generates an offset current to track the supply voltage transient or change. . For example, resistor R1 is coupled between a supply voltage (VBAT) and a current mirror circuit (Q1 Q2) that conducts a first current proportional to the supply voltage (e.g., IBAT = (VBAT - VGS) / R1). The current mirror circuit conducts a first current on one input side (eg, via Q1) and a corresponding second current on the output side (eg, via Q2). The addition resistor R2 also conducts a second current (or offset current). The summing resistor R2 is coupled in series between the error amplification crying wheel and the input of the PWM comparator 404 without the use of a capacitor having a solid junction (e.g., DC-coupiing). The voltage at the input of the ρ· comparator 404 (eg, (10), the adjusted error voltage or the compensated PWM control signal) is approximately equal to the error voltage of the output of the error amplifier (Verr or the original PWM control signal) minus the averaging resistance R2. ('or offset voltage is said to be XR2) voltage drop. Thus, the offset voltage is combined with the step voltage to produce a compensated simple control signal (or adjusted error voltage) that advantageously responds quickly to changes in the supply voltage. „Apparel ^Resistance Benefits R1, R2 resistance value' can instantly correct the PWM ratio = 404 - output or change the pulse width (or work week plastic maternal * generate an error voltage relative to the slower Electric ς 'Broken and generated - ramp wave - (Vr Qing) ramp generator is the main part of the genera1 ^ system (four) ground is not for this transient correction error amplifier wheel and provide the compensation comparator 4〇4 The change of the ramp wave is not as fast as the change of the offset voltage. In the example of 96137068 1361553, the above-mentioned inverse feedforward compensation circuit provides the output pulse width compensation within the period of the oblique wave power. The pulse width correction of the thinner is an ideal function of 1/χ, and the middle X corresponds to the input voltage of the power supply. Aligning with the curve, the above-mentioned 9 η-type operating power input input range is acceptable: Change = medium / linear ). For example, in one of the above embodiments, "excessive or insufficient amount of "less than" is indicated in "iine transients" with respect to volts having a transition time of about 10 microseconds. The whole output electric house shows a PWM-based electric 麈 adjuster. Under the operating conditions, the reciprocal product relationship between the supply voltage and the PWM duty cycle is intended to help stabilize the output of the electrical waste. Some feedforward correction circuits use complex circuit designs to implement a reciprocal product relationship. Some feedforward correction circuits can complicate the design of circuits that do not ideally reciprocal product relationships, or require external circuit components. In one embodiment of the invention, the inverse feedforward compensator (inverse feed_f〇rward c〇mpensat〇r) uses a linear transconductance principle to implement a reciprocal product relationship. The inverse feedforward compensator can advantageously be implemented as part of the PWM controller ic without external components and using no more than one additional package pin to display the supply voltage level (or battery input voltage). Figure 7 illustrates a general linear transconductance circuit. For example, four bipolar junction transistors (BJT) (Qi, Q2, Q3, Q4) are arranged to conduct four collector currents (In, ^, ,, respectively).

Ic4) 'The base-emitter voltage (Vbei, Vbe2, Vbe3, Vbe4) has the following 96137068 19 1361553 relationship: ^ΒΕΙ +^β£3 ~^ΒΕ2 ~~^ΒΕ4 ( \ ) According to the double carrier junction For the Ebers-Moll model of crystal (BjT), the base-emitter voltage and collector current have the following general relationship: 2)

^s(eVr -\)^ ! evT The "Vt" term corresponds to a thermal voltage (thermal v〇 approximately equal to kT/q (for example, approximately 26 mV at room temperature of approximately T = 300 Kelvin). Ltage). The "Is" term corresponds to the reverse saturation current of the base-emitter diode from 1 〇15 amps to 1 (Γ12 amp level. Rewritten according to the result of collector current) Equation (1), the resulting formula: ι^~ + ίη^--\ηί£1_]ηΙ£± Sl S3 I si lsa,

kT 0 q Use algebraic operation, equation (3) (3) ΘΕ _ yj, · spoon after the difference and not in the following relationship: 卞 position 爪 / claw month lcJc3 ^S1^S3 I SI! S4 is that the first pair of collector currents (for example, the ratio of the product of the second pair of 隹丨 and 10 in the general linear transconductance circuit is proportional to the β electric machine (eg 'IC2 and Ic (4)

Product of K T C〇&gt; 96137068 20 1361553 1361553

48 = Figure 88 illustrates the configuration to provide an output current!. The linear transconductance ... turns out... is inversely proportional to the input switching current (1 coffee c_erted ah...Πΐ) or battery switching current (battery c〇nverted m) (lBAT). For example, four transistors n, are arranged as shown in Fig. 8A such that their base-emitter voltages have a relationship as defined by the above equation (1). In the arrangement of Figure 8A, the first and third transistors (9), (6) have a collector terminal that is connected to the f-base terminal in the diode configuration and the first and third transistors (Q1, Q3) are coupled in series. Conduction-offset (or reference) current (eg, In = Ic3 = lR). a second transistor ((8) conducts an input switching current corresponding to the transconductance output. For example, a current source (or current sink) is coupled to the emitter of the second transistor and can be based on a PWM controller The input signal is generated by the control signal generated by the error amplifier. The fourth transistor (Q4) conducts the output current. According to equation (4), and assumes that these transistors have comparable reverse saturation currents, then Figure 8A The current has the following relationship:

h II (5) That is, the output current II· generated by the linear translinear circuit in Fig. 8A is proportional to the square of the bias current and inversely proportional to the wheel-in conversion current. Figure 8B illustrates a transistor arrangement substantially similar to that of Figure 8A and including an additional current source to produce an output current I. The output current 1 成 is proportional to the input switching current (I i ) and is inversely proportional to the battery switching current (IBAT). Similar to FIG. 8A, in FIG. 8B, the first transistor (qi) conducts a bias current (96137068 21: the fourth transistor Q4 provides an output current Π〇) β, which is different from that of FIG. 8A, and converts the current source and the conduction bias of the current. The current sink of the galvanic current is turned on by the collector 8: the collector's terminal of the two transistors (10) so that the switching current is turned in the third transistor conduction diagram 8. Unlike in Fig. 8A, in the graph, the second: = (Q2) conduction Battery switching current. For example, battery switching current is generated by current, motor slot, current source or current tank sensing supply voltage (such as 'output from battery or AC power adapter) and battery conversion and supply voltage #进+ y, ^ The position of I is abundance. Therefore, the current in the linear transconductance of Figure 8β has the following relationship: 1 bat 6) The input current can be obtained from the control signal or the error signal generated by the error amplifier. And the battery switching current is obtained from the supply voltage. The linear transconductance circuit in Figure 8B is configured to maintain a reciprocal product relationship between the output current and the battery switching current. That is, the output current is proportional to the input switching current. It is inversely proportional to the battery switching current. The bias current or reference current is a constant term used to scale down the output current. The output can be supplied to the resistor network to generate a voltage (eg, tuned to the difference U) 'This voltage is supplied to the &amp; just ratior in the trim controller. Fig. 2 is a schematic diagram of the implementation of one of the inverse feedforward compensation circuits by the linear transconductance circuit 9〇6. The first current of the voltage (eg, the error voltage from the error amplifier) and the second current corresponding to the second current of the supply voltage (eg, purchased or battery voltage), linear 96137068 22 1361553 transconductance circuit 906 produces an output (eg, p The adjustment error signal of the comparator is). In an embodiment, the first current is provided by the first voltage current converter 900, and the first voltage current converter 9 has an input coupled to the output of the error amplifier, and The second current is provided by a first voltage current converter 902 coupled to the supply voltage. In one embodiment, the inverse feed forward compensation

The inverse feed-forward compensator is implemented in a BiCMOS ‘private with a double-carrier junction transistor and a metal oxide semiconductor transistor (MOS). In the implementation shown in Figure 9, the inverse feedforward compensator also includes a circuit network 904 that reduces the transistor error in the linear transconductance circuit 9〇6, as will be described in more detail below. In the first voltage current converter 900, the level of the transistor p4 〇 (for example, a pM 〇s transistor) is shifted by an input voltage ΙΝρ υτ, and the level of the transistor p44 is shifted by a reference voltage of 2.25 V (V2P25). In the case of the application, the input voltage is the voltage of the error voltage from the error amplifier, and the input voltage is a DC voltage of 0.5 V and 4. 0 V. 2. The 25V reference voltage is the midpoint of the input voltage range. The transistors Q9, N17, N18 and resistor r〇 convert the input power into a corresponding current. For example, the switching current is generated based on the differential voltage between the input voltage and the 2.25V reference voltage. When the input voltage is approximately 0.5V, the differential voltage is approximately _175V and the conversion current is approximately 20μΑ (or maximum switching current). When the input voltage is approximately 4 〇v, the differential voltage is approximately +丨.75V and the switching current is approximately 卟A (or minimum switching current). 96137068 23 1361553 The switching current is mirrored by transistors P15 and P18. The current conducted by the transistor p 18 is compared to the current source of 20 μΑ conducted by the transistor N19 and the difference is conducted by the transistor Ρ19. This effectively remaps (remap) the conversion current. That is to say, when the switching current is 2 〇 μ A , the transistor p 1 9 conducts ΟμΑ ', when the switching current is 〇μΑ, the transistor Pi 9 conducts 20 μΑ. Re-mapping the conversion current helps ensure that transistor Q9 does not saturate when the input voltage is high (eg, 4. 〇ν). The transistor 26 is a cascade of current sources for the transistor N1 9 . The current conducted by transistor P19 (e.g., the first current or input current corresponding to the input voltage) is mirrored to linear cross-talk circuit 906. A second current (or VBAT current) that is dependent on the battery voltage is also mirrored to the linear transconductance circuit 906. The second voltage current converter 9〇2 generates a second current based on the difference between the battery voltage VBE of the electric crystal Q1 and the voltage drop across the resistor ri. The VBAT current is mirrored to the linear transconductance circuit 9〇6 via the transistor Q1 to a transistor Q2. The VBAT current is also mirrored to the electric switch Q7, and the transistor Q7 is connected to the circuit network 9〇4 to reduce the NPN base current error in the linear transconductance circuit 906. In one embodiment, the high voltage PMOS switch M2 turns off the battery voltage in a disabling mode. M2 P# is turned on or off by the voltage across the resistor R6. • When the inverse feedforward compensator is enabled, transistor N28 sends current to the resistor. Μ ' to generate a Vgs voltage to turn on the M2 switch. When the inverse feedforward compensator is lost, the transistor N28 does not conduct current and the voltage does not generate across the resistor R6 to turn on the M2 switch. 96137068 24 1361553 In one embodiment, the NPN base current in linear transconductance circuit 9Ο6 is compensated by circuit network 904, which is formed by transistors Q7, Q8, P41, P42. The NPN base current error is dependent on the strength of the VBAT current from the second voltage: current transformer 902. As the VBAT current increases, the NPN base current error also increases. The VBAT current is mirrored from the transistors Q1 to Q7 and sent to the transistor Q8. The collector current and base current of transistor Q8 change as a function of (or tracking) the VBAT current. The base of the transistor Q8 is connected to a diode-connected dio-connected PMOS P41, and the PMOS P41 is mirrored to the transistor P42. The current conducted by transistor P42 is passed to linear transconductance circuit 906 and used to reduce the base current error in linear transconductance circuit 906. The following description of the linear transconductance circuit 906 is associated with the circuits illustrated in Figures 4 and 5. The reference current h is conducted by the transistor P0 and is sunk by the transistor N13. The battery switching current IBAT is taken by the transistor Q2. The input switching current I i is obtained by the transistor P20 • ( sourced ). Figure 5 includes some additional transistors to improve circuit accuracy. For example, transistors Q12, Q13, and Q10 are used to match the collector to emitter voltage (VCE) for each primary linear translinear transistor. That is to say, the transistor Q10 is used to match the VCE of the linear trans-conducting crystal Q3, .Q6. The transistors Q12, Q13 are used to match the VCE of the linear linear transconducting crystals Q4, Q5. The collector current of transistor Q10 is the output current I of linear transconductance circuit 906. . The output current is mirrored by transistors P5, P6 and converted to a voltage by resistor R3 (for example, to adjust the error voltage). 96137068 25 1361553 is not intended to limit the invention, any person having ordinary knowledge in the art, without leaving too much

1 is a diagram of a switching voltage regulator in accordance with an embodiment of the present invention. Although the present invention has been disclosed in the embodiments as a block diagram. Figure 2A illustrates an embodiment of a buck converter. Figure 2B illustrates an embodiment of a boost converter. Figure 3A illustrates an embodiment of a push-pull converter. Figure 3B illustrates an embodiment of a full bridge converter. 4 is a simplified block diagram of an embodiment of a pwM controller with an inverse feedforward compensation circuit. The inverse feedforward compensation circuit adjusts the error signal to compensate for transients in the supply voltage. Figure 5 illustrates an embodiment of how the reverse adjustment error signal relates to variations in supply voltage in an application. Figure 6 illustrates an embodiment of a reverse feedforward compensation circuit that generates an offset signal based on the supply voltage and combines the offset signal with the error signal to inversely adjust the PWM output with respect to the supply voltage. b Figure 7 illustrates a general linear transconductance circuit. 8A and 8B illustrate a linear transconductance circuit configured to generate an output current that is inversely proportional to an input switching current or a battery switching current. 96137068 26 1361553 FIG. 9 is a schematic diagram of an embodiment of an inverse feedforward compensation circuit implemented by a linear transconductance circuit. [Main component symbol description] 100, 210, 220, 308, 318: PWM controller • - 102: switching circuit 104: load 106: feedback circuit 200: first semiconductor switch Lu 202: diode 204: inductor 206 Output capacitor 208: output resistor 212: semiconductor switch 214: isolation diode 216: feedback circuit 218: input inductor 300 to 303: semiconductor switch 312: fluorescent lamp '400: inverse feedforward compensator. 402 Transconductance amplifier. 404: PWM comparator 406: capacitor 900: first voltage current converter 902: second voltage current converter 96137068 27 1361553 904: circuit network 906: linear transconductance circuit FB: feedback signal I BAT : battery switching current

Ici, Ic2, Ic3, Ic4: Collector current I i : Input switching current INPUT : Input voltage 1〇: Output current h : Bias current M2 : Switches N13, N14, N17~N19, N25, N26, N28, P0 ~ P2, P5~P6, P10, P14~P16, P18~P20, P37, P40~P42, P44, Q0~Q10, Q12, Q13: Transistor PWM-OUT: PWM output R0, Rl, R6: Resistor R2: Addition resistor REF : Reference signal V2P25 : Reference voltage

Vadj: Adjusting the error signal VBAT: Power supply sensing signal

VbEI, VbE2, VbE3, VbE4: base-emitter voltage

Verr: error signal

Vfb: feedback voltage

Vout : Adjusted output voltage 96137068 28 1361553 ( • &lt; ( Xiu Lin minus Vpwm : Pulse width modulation drive signal Vramp : Ripple signal Vref : Reference voltage Vsupply · Supply electric remote VpWMI, VpffM2 : Variable pulse width drive signal • 96137068 29

Claims (1)

II MAR 1 5 2fil1 Replace the car on the day of repair (more) stop replacement page 40ΰ-Β__1_5_Ζ__ Ten, the scope of application for patent: 1. - kind of used for switching voltage tuning crying for Kulei steam aunts to recognize D &lt; 1 system State, the controller receives a supply of electricity [, sub-generating an output voltage to the load, the one-in-one terminal, configured to receive - ° °. It has been included. It is not used for the feedback signal of the switching voltage 镅敕 令 输出 ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; - reference 俨: factory tiger 'where the reference signal indicates - the desired output condition for the switching voltage regulator; for a switching a feedforward circuit, configured to directly transfer to the first input of the error amplifier The terminal receives the 5 singularity difference ' from the error-amplified VIII, and the first directly connected to the supply voltage: the receiving end receives the indication ^ bit = the sensing signal, wherein the feedforward circuit takes - The output is generated; the adjustment error signal of the real and upper and the difference of the heart difference k #υ, and the adjustment of the feedforward circuit in the basin, the adjustment, the difference (4) in the (four) supply electric energy level sensing signal The decrease time is increased, and the indication supply voltage level is decreased when the sense signal is increased, such that the adjustment error signal is related to the received error signal to substantially correspond to the sensed supply voltage level In inverse proportion Adjusting; oscillating, configured to generate a periodic ramp voltage whose frequency does not change according to the; and wherein: the pulse width modulation comparator is configured to receive from the inverse feed circuit with a first input Outputting the adjusted error signal, and receiving the periodic ramp voltage from the oscillator with a first input coupled to the oscillation of the oscillation threshold, the pulse width modulation tb is configured based on the H system The adjustment error 96137068 difference H is more than the replacement of wl 唬 and 垓 periodic ramp voltage to produce the --- number, and by the 兮 plus ten pulse see 颂 ^ turn out for the 戎 supply voltage level and the pulse width adjustment Change 1. The product of the period for the work of H Fu Laohuhu ^ 4 inch 疋 reference h唬 is the essence 2 · as claimed in the scope of the scope of the controller, (4): The whole device includes at least one semiconductor switch, And the pressure regulates the semi-conductor, and the friend of the k5 tiger controls the conductor switch to have a substantially constant output power due to the electric dust regulator in the supply voltage. Controller of item 1, wherein the feedforward circuit pack: voltage control The flow source is configured to receive the sensing signal and generate a furnace _ $ 1 八 屯 屯 位 , , , 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 盆 中 中 中 中An addition resistor having a first end and a switching emitter. The output of the error amplifier is connected to the U f M control current source - the second of the output: the tr method resistor conducts the offset current, and the Adjusting the error signal is provided at the second end of the adding resistor. The controller of the first item, wherein the feedforward circuit package; and the plurality of transistors configured by the second v are configured to conduct at least one first The electric::::帛 current signal and the third current signal, wherein the product of the first---, the motor 彳§娆 and the third current signal are proportional to each other. = The controller of claim 4, wherein the first current signal (4) 'the second current signal is derived from the sensing of the 96137068 31 secondary current signal supply voltage level The signal produces the adjustment error signal. 3 The controller of claim i, wherein the feedforward circuit package method is configured to generate an output current signal according to a -first current signal and a second one, wherein the output current signal system The current signal is proportional to and inversely proportional to the second current signal. The current signal corresponds to the error I generated by the error amplifier, and the first current signal corresponds to the bullying 1Ms indicating the supply voltage level. number. The controller of claim 6, wherein the feedforward circuit is configured to generate a second current from the error signal and configured to generate the power from the sensing signal. Ids 唬 second voltage current converter. Please refer to the controller of the first item of the patent scope, wherein the adjustment error is made as follows: the periodicity of the periodic ramp voltage - the supply (four) level in the half cycle. The whole 9==== controller of the first item, wherein the switching voltage adjusts the duty cycle of the output signal and changes the pulse. . The power level and the output voltage level delivered to the converter. m to DC power supply becomes 1 〇. As in the scope of patent application 帛1, J, J: 中' adjuster is a change μ "Shixin which switch voltage you. Month" it has a heart pulse width modulation wheel Write a letter! Lu's work cycle and change 铪 φ with two γ l 现 现 现 现 现 现 现 现 现 现 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 96 According to a feedback signal and a number; the error signal of the first device of a feedforward circuit; the difference between the reference signals generates an error signal, and the input end receives directly from the error amplification Sensing a supply voltage level with the second input terminal of the feedforward circuit directly pure to the supply voltage; and the feedforward circuit according to the received error signal and the sensed supply electric house level Generating an adjustment error signal, wherein the generated modulation is proportional to the error signal, and wherein the adjustment error is increased when the sensed supply voltage level decreases, and the sense supply voltage level is increased When the quasi-increase is reduced, the adjustment error is adjusted in the manner that the error signal of the connection (4) is inversely proportional to the sensed supply voltage: and the adjustment error signal is related to the error signal received Adjusting in inverse proportion to the sensed supply voltage; generating, by an oscillator, a periodic ramp voltage whose frequency does not change according to the adjusted error signal; and ° 7ϋ 96137068 33 丄*361 m一一- [Year of the Moon (more) is replacing the page L4g〇_2L^l_5„.__ According to the comparison of the whole error signal and the Langer-Rock signal, using the =乂 state to generate a pulse width modulation Turn out signal' The periodic ramp signal directly from the oscillator is pure by the comparator, wherein the product of the sensed supply voltage level and the duty cycle of the pulse width modulated output signal is substantially for a particular reference signal The method of claim 12, wherein the generating the error β includes generating an offset signal that tracks the supply voltage level, and combining the offset signal with the error signal to generate the adjustment error The method of claim 12, wherein the generating the difference signal comprises: generating a first current signal that tracks the error signal; generating a second current signal that tracks the supply voltage level; The first current signal and the second current signal are provided to a linear cross circuit ' to generate a third current signal proportional to the first current signal and inversely proportional to the second current signal, wherein the third current signal Used to generate the adjustment error signal. 15. The method of claim 12, further comprising driving the pulse width modulated output signal A semiconductor switch for generating an output voltage to the voltage regulator. 16. The method of claim 12, wherein the voltage regulator is an inverter that controls a lamp power, the feedback signal indicating a lamp The tube current, and the reference signal is indicative of the desired brightness of the tube. The method of claim 12, wherein the voltage regulator is a DC-to-DC voltage regulator, the feedback signal is indicative An output power 96137068 34 1361553 • % pressure level, indicated by the money reference signal system - 18. A pulse width modulation controller, comprising: generating a segment of the error signal according to a feedback signal and a reference signal; And generating a method for adjusting the error signal, wherein the first input end of the means for generating the error signal receives the error signal directly from the means for generating an error signal, and directly by means for generating the adjusted error signal The second input end coupled to the supply voltage receives a supply voltage 1 to generate the adjustment error signal, wherein the adjustment error signal is generated According to the error signal and a supply voltage level, wherein the adjustment error is proportional to the error signal, and wherein the adjustment error signal is increased when the X supply -3⁄4 pressure level decreases, and When the supply voltage level is increased, the adjustment error signal is caused by the generation of an adjustment error 7 and related to the received error signal to the sensed supply voltage level. Substantially inversely proportional to the adjustment; • generation—a means by which the frequency does not change the periodic ramp voltage according to the adjusted error signal; and means for generating a pulse width modulated output signal, the pulse width modulated output signal The duty cycle varies with the adjustment error signal, wherein the means for generating the pulse width modulated output signal is configured to receive the periodic ramp voltage directly from the means for generating the periodic ramp voltage. The pulse width modulation controller of claim 18, wherein the means for generating the adjustment error signal comprises: generating a means for tracking a variation of the supply voltage level, and combining the offset signals With the 96137068 13⁄4 day shot more) is the means of changing the page m 1 51^- error signal. 20. The pulse width modulation controller of claim 18, wherein the means for generating the adjusted error signal comprises: generating a means for tracking the error as a current 彳s number to generate a tracking of the supply And means for generating a second current signal of a voltage level and for generating a third current proportional to the first current signal and inversely proportional to the second current signal. 96137068 36