RLs   L             BOOST_SW                                                                 v out                        ...
Contents • The PWM Boost Converter Topology (Voltage Mode)    – Averaged Boost Switch Model • Boost Converter Design Workf...
The PWM Boost Converter Topology             Power Stage: Boost topology              RLs    L             BOOST_SW       ...
Averaged Boost Switch Model                             IIN           BOOST_SW                   IOUT                     ...
Boost Converter Design Workflow                        1 Setting PWM Controller’s Parameters: VREF, VP                    ...
Buck Regulator Design Workflow        3    RLs   L             BOOST_SW                                                   ...
Design Specification (Example)A boost converter is designed to deliver 12V, 1.5A from a 3.3 V batteryStep-Up (Boost) Conve...
1       Setting PWM Controller’s Parameters             D                                                           • VREF...
1   Setting PWM Controller’s Parameters (Example)The VREF value is given by the datasheet    TPS43000 electrical character...
1   Setting PWM Controller’s Parameters (Example)The VP ( sawtooth signal amplitude ) can be calculated from the character...
2   Programming Output Voltage: Rupper, Rlower• Use the following formula to select the resistor values.                  ...
2   Programming Output Voltage: Rupper, Rlower• This calculation could be completed by using the Boost Converter Calculato...
3       Inductor Selection: L, RLS    L         BOOST_SW                              Inductor Value                      ...
3       Inductor Selection: L, RLS (Example)    L         BOOST_SW                                        v out           ...
3   Inductor Selection: L, RLS (Example)• This calculation could be completed by using the Boost Converter Calculator (Exc...
4       Capacitor Selection: C, ESR    L         BOOST_SW                                 Capacitor Value                 ...
4   Capacitor Selection: C, ESR (Example)    L1        2           Vo       Capacitor Value                              F...
4   Capacitor Selection: C, ESR (Example)• This calculation could be completed by using the Boost Converter Calculator (Ex...
4   Capacitor Selection: C, ESR (Example)• A SMD type electrolytic capacitor from NIPPON CHEMI-CON, part no.  EMZJ160ADA47...
5   Stabilizing the Converter                                                                                             ...
5    Stabilizing the Converter (Example)Converter parametersConverter parameters                                    RLs   ...
5    Stabilizing the Converter (Example)                                                                     Frequency Res...
5    Stabilizing the Converter (Example)• This calculation could be completed by using the Boost Converter Calculator (Exc...
5       Stabilizing the Converter (Example)                                                                    Frequency R...
5        Stabilizing the Converter (Example) • This calculation could be completed by using the Boost Converter Calculator...
5    Stabilizing the Converter (Example)                                                                      Frequency Re...
5    Stabilizing the Converter (Example)                           Gain and Phase responses after stabilizing            8...
Load Transient Response Simulation (Example) The converter, that have been stabilized, are connected with step-load to per...
5    Stabilizing the Converter (Example)                             Step-load transient responses after stabilizing      ...
A. Boost Converter Calculator (Excel sheet) 1/3Boost Converter Calculator (Excel sheet)The following specs are needed to c...
A. Boost Converter Calculator (Excel sheet) 2/3The following specs are needed to calculate the controller stage:      VRE...
A. Boost Converter Calculator (Excel sheet) 3/3 Type 3 Compensator Calculator        Rload,min          8W            ; = ...
B. Feedback Loop Compensator                                VOUT                                                VOUT      ...
C. Simulation Index Simulations                                                                                      Folde...
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Concept Kit:PWM Boost Converter Average Model

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Concept Kit:PWM Boost Converter Average Model(PSpice Version)

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Concept Kit:PWM Boost Converter Average Model

  1. 1. RLs L BOOST_SW v out D C R Vin ESR 10V C2 0 R2 C1 R1 Rupper C3 - err {1/Vp} + Rlower VrefConcept Kit: 0 0PWM Boost Converter Average Model All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 1
  2. 2. Contents • The PWM Boost Converter Topology (Voltage Mode) – Averaged Boost Switch Model • Boost Converter Design Workflow – Design Specification (Example) 1. Setting PWM Controller’s Parameters. 2. Programming Output Voltage: Rupper, Rlower 3. Inductor Selection: L, RLS 4. Capacitor Selection: C, ESR 5. Stabilizing the Converter (Example) • Load Transient Response Simulation (Example) Appendix A. Boost Converter Calculator (Excel sheet) B. Feedback Loop Compensators C. Simulation Index All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 2
  3. 3. The PWM Boost Converter Topology Power Stage: Boost topology RLs L BOOST_SW v out D C R Vin ESR 10V Error Amplifier C2 0 R2 C1 R1 Rupper PWM Modulator Gain: C3 1/Vp - Type 3 Compensator* Vp err {1/Vp} + Rlower Vref Voltage Mode 0 0 * Please see appendix B for the detail All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 3
  4. 4. Averaged Boost Switch Model IIN BOOST_SW IOUT + D + VIN VOUT D - - • The Averaged Boost Switch Model represents relation between input and output of the switch that is controlled by duty cycle – d (value between 0 and 1). VIN • Transfer function of the model is VOUT  1  D  (1) IOUT • The current flow into the switch is IIN  (2) 1  D  All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 4
  5. 5. Boost Converter Design Workflow 1 Setting PWM Controller’s Parameters: VREF, VP 2 Setting Output Voltage: Rupper, Rlower 3 Inductor Selection: L, RLs 4 Capacitor Selection: C, ESR 5 Stabilizing the Converter: Type 3 Compensator: R1, R2, C1, C2, and C3 • Step1: Open the loop with LoL=1kH and CoL=1kF then inject an AC signal to generate Bode plot. • Step2: Run the AC sweep without compensator. • Step3: Select a crossover frequency, fc , select the value a little lower than the suggested value. • Step4: Read the Gain value (dB) at the fc from the Bode plot, Then put the values to the sheet. • Step5: R C values are suggested, input the values to the elements of the compensator. 6 Load Transient Response Simulation All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 5
  6. 6. Buck Regulator Design Workflow 3 RLs L BOOST_SW v out D C R Vin ESR 10V 4 Type 3 Compensator* C2 0 5 5 R2 C1 R1 Rupper C3 - err {1/Vp} + Rlower Vref 2 1 0 0 * Please see appendix B for the detail All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 6
  7. 7. Design Specification (Example)A boost converter is designed to deliver 12V, 1.5A from a 3.3 V batteryStep-Up (Boost) Converter : • Vin,max = 3.63 (V) Vin = 3.310% • Vin,min = 2.97 (V) • Vout = 12 (V) • Vout, ripple = 180mVP-P (1.2%) • Io,max = 1.5 (A) • Io,min = 0.2 (A)Control IC : • Part # TPS43000 (PWM Controller IC) • Switching Frequency – fosc = 300 (kHz) All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 7
  8. 8. 1 Setting PWM Controller’s Parameters D • VREF, feedback reference voltage, value is given by the datasheet - FB • VP = the sawtooth peak voltage. ERR {1/Vp} + • If VP does not provided, it could be calculated Error-Amp Vref from: VP = VFB /d (3) 0 VFB = VFBH – vFBLThe Error-Amp. is used to transfer the error voltage d = dMAX – dMIN(between FB and VREF) to be the duty cycle. where3.0V vFBH is maximum FB voltage where d = 02.0VSEL>> VP vFBL is minimum FB voltage where d =1(100%) 0V V(osc) V(comp) dMAX is maximum duty cycle, e.g. d = 0(0%) dMIN is minimum duty cycle, e.g. d =1(100%) Duty cycle (d) is a value from 0 to 1 • fosc = Modulation frequency or switching V(PWM) Time frequency .  If vFBH and vFBL are not provided, the default value, VP=2 could be used. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 8
  9. 9. 1 Setting PWM Controller’s Parameters (Example)The VREF value is given by the datasheet TPS43000 electrical characteristics So we’ve got VREF = 0.8 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 9
  10. 10. 1 Setting PWM Controller’s Parameters (Example)The VP ( sawtooth signal amplitude ) can be calculated from the characteristics below. TPS43000 electrical characteristics from eq. (3) VP = VFB /d • from the datasheet , VFB = (2-0) = 2V, and d = (0.9-0) = 0.9 VP = 2 / 0.9 = 2.2 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 10
  11. 11. 2 Programming Output Voltage: Rupper, Rlower• Use the following formula to select the resistor values.  Rupper  Vout  Vref 1   (4)  Rlower  Rupper DExampleGiven: Vout = 12V - err Vref = 0.8 {1/Vp} + Rlower Rlower = 10k Vrefthen: (VOUT  VREF)  Rlower Rupper  VREF Rupper = 140k 0 0 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 11
  12. 12. 2 Programming Output Voltage: Rupper, Rlower• This calculation could be completed by using the Boost Converter Calculator (Excel sheet).• After input all the boost converter specs and the Rlower value then Rupper is automatically calculatedBoost Converter Calculator (Excel sheet)The following specs are needed to calculate the power stage:Spec: Vin,max 3.63 V Vin,min 2.97 V The power stage spec Vout 12 V values are input Vout,ripple 0.18 V ; 1% ripple value Io,max 1.5 A Io,min 0.2 AThe following specs are needed to calculate the controller stage: VREF 0.8 V The controller spec values Vp 2.2 V are input fOSC 300 kHz Rlower 10 kW Input the Rlower value, then Rupper 140 kW Rupper is auto-calculated All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 12
  13. 13. 3 Inductor Selection: L, RLS L BOOST_SW Inductor Value v out • The output inductor value is selected to set D C R the converter to work in CCM (Continuous ESR Current Mode) for all load current conditions. • Calculated by D min (1  D min) 2 VOUT LCCM  (5) 2  fosc  IO , min • with Vin, min D max IL  (6) Where L  fosc • LCCM is the inductor that make the converter to work in CCM. • Dmax is the maximum duty cycle; Dmax =1- Vin,min /VOUT • RLs is load resistance at the minimum output current ( Io,min ) • fosc is switching frequency • IL is inductor ripple current All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 13
  14. 14. 3 Inductor Selection: L, RLS (Example) L BOOST_SW v out Inductor Value D C R from eq. (5) ESR D min (1  D min) 2 VOUT LCCM  2  fosc  IO , min Given: • Vin,max = 3.63V (3.3V+10%), Vout = 12V, Io,min = 0.2A • Dmin = 1- Vin,max /Vout = 0.7 • fosc = 300kHz Then: • LCCM  64 (uH), • L = 68 (uH) is selected All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 14
  15. 15. 3 Inductor Selection: L, RLS (Example)• This calculation could be completed by using the Boost Converter Calculator (Excel sheet).• After input all the known parameters, this sheet will suggest the inductor L value, using eq. (5) Dmax 0.75 ; = 1- Vin,min/Vout Dmax and Dmin are auto-calculated Dmin 0.70 ; = 1- Vin,max/Vout  L> 6.4 uH ; suggested inductor L value (from eq.5) L= 6.8 uH ; the selected inductor L value RLs 10 mW ; the selected inductor, series resistance value IL 1.10E+00 A ; calculated inductor ripple current (from eq.6) The excel sheet suggests an inductor value, by using eq. (5). Then input your inductor L value (> suggested value), and RLs value of the inductor for further calculation. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 15
  16. 16. 4 Capacitor Selection: C, ESR L BOOST_SW Capacitor Value v out • The minimum allowable output capacitor D C R value should be determined by ESR D max Io , max C (7) Vout, ripple  fOSC• In addition, the capacitor must be able to handle the current more than IL IC , Rated  (8) 2 • Where IL is calculated by eq. (6)• The ESR of the output capacitor adds some more ripple, so it should be limited by following equation: Vout, ripple ESR  (9) IC All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 16
  17. 17. 4 Capacitor Selection: C, ESR (Example) L1 2 Vo Capacitor Value From eq. (7) D max Io , max C C Rload Vout, Ripple fOSC ESR and eq. (8) and eq. (9) IL Vout, ripple IC  ESR  2 IC Given: • Dmax = 0.75 V • Io, max = 1.5 A • Vout,ripple = 0.18 V Then: • C  20.9 (F) In addition: • IC,Rated ≈ 550mA  ESR  27mW All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 17
  18. 18. 4 Capacitor Selection: C, ESR (Example)• This calculation could be completed by using the Boost Converter Calculator (Excel sheet).• After input all the known parameters, this sheet will suggest the capacitor C and ESR value, using eq. (7) and eq. (9).  C 20.9 uF ; eq. (7) suggested value C 1410 uF ; the selected Capacitor C value ESR < 0.027 W ; eq. (9) suggested value ESR = 0.027 W ; the selected capacitor ESR value IC,Rated ≈ 0.55 A ; Rated ripple current The excel sheet suggests an capacitor value, by using eq. (7) and ESR value by using eq. (9). Then input your capacitor C Value and the capacitor’s ESR value for further calculation. The capacitor’s rated current should be more than the suggested value IC All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 18
  19. 19. 4 Capacitor Selection: C, ESR (Example)• A SMD type electrolytic capacitor from NIPPON CHEMI-CON, part no. EMZJ160ADA471MHA0G is selected with the following characteristics. EMZJ160ADA471MHA0G C 470 uF Vdc 16 V ESR = 0.08 W Rated Ripple Current 0.85 Arms• The suggested ESR should be less than 27 mW, three of these part will be put in parallel to meet the converter specs.• So we select the capacitor C value = 470uF  3 = 1410 uF, with ESR = 0.08W / 3 = 0.027W All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 19
  20. 20. 5 Stabilizing the Converter Power Stage: H(s) RLs L U1 {RLs} {L} BOOST_SW v out D ESR {ESR} Rload {Vout/Io_max} Vin {Vin_min} C {C} Compensator: G(s) C2 0 {C2} R2 {R2} PWM: GPWM GAIN1 {1/Vp} C1 R1 Rupper {Rupper} C3 {C1} {R1} {C3} LOL - err• Loop gain for this configuration is 1kH U2 + COL 1kF ERRAMP Vref T ( s)  H ( s)  G( s)  GPWM {Vref } Rlower {Rlower} Vac 1Vac 0 0• The purpose of the compensator G(s) is to tailor the converter loop gain (frequency response) to make it stable when operated in closed-loop conditions. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 20
  21. 21. 5 Stabilizing the Converter (Example)Converter parametersConverter parameters RLs L U11 PARAMETERS: PARAMETERS: {RLs} {L} BOOST_SW v out Vin_min = 2.97 Vin_min = 2.97 D Vout = 12V Vout = 12V ESR Io_max = 1.5A Io_max = 1.5A {ESR} Vref = 0.8 Rload Vp = 2 1 Vin {Vout/Io_max} 2.2 C {Vin_min} Rlower = 10k {C} Rupper = 140k 2 L = 6.8u RLS = 10m 3 0 G(s) C2 {C2} R2 C = 1410u {R2} GAIN1 Rupper ESR = 27m 4 {1/Vp} C1 R1 {Rupper} C3 {C1} {R1} {C3}Type 3 compensator parameters LOL err - 1kH + PARAMETERS: COL 1kF Vref C1 = ? {Vref } Rlower C2 = ? Task: to find out the elements of {Rlower} Vac C3 = ? the Type 3 compensator ( C1, C2, 1Vac R1 = ? C3, R1, and R2 ) 0 0 R2 = ? All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 21
  22. 22. 5 Stabilizing the Converter (Example) Frequency Response without Compensator.Converter parameters U1 T ( s)  H ( s)  GPWM RLs L PARAMETERS: {RLs} {L} BOOST_SW v out Vin_min = 2.97 Vout = 12V D d Io_max = 1.5A ESR {ESR} Vref = 0.8 Rload 1 {Vout/Io_max} Vp = 2.2 Vin {Vin_min} C Rlower = 10k {C} 2 Rupper = 140k L = 6.8u 3 Step2 Run the AC RLS = 10m 0 sweep. without C = 1410u Compensator. ESR = 27m 4 GAIN1 {1/Vp} Rupper {Rupper} LOL - err 1kH + U2 COL ERRAMP Step1 Open the loop with 1kF Vref Rlower {Vref } LoL=1kH and CoL=1kF Vac {Rlower} then inject an AC signal to 1Vac generate Bode plot. 0 0  C1=1kF is AC shorted, and C2 1fF is AC opened (or Error- Amp without compensator). All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 22
  23. 23. 5 Stabilizing the Converter (Example)• This calculation could be completed by using the Boost Converter Calculator (Excel sheet).• After input all the known parameters, this sheet will suggest the crossover frequency fc value, and the maximum input voltage Vin,max . Step3 Select a crossover frequency-fc the maximum fc is automatically Type 3 Compensator Calculator calculated from the boost converter spec and condition. Select the value a Rload,min 8 W ; = V /I out o,min little lower than the suggested value. fc < 3440.91 Hz ; fc < 0.3 times RHPZ, fz2 fc = 3000 Hz ; select the value of fc Vin,max < 7.38 V ; Vin,max suggested value The Vin,max suggested value shows the maximum input voltage that the converter could be used. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 23
  24. 24. 5 Stabilizing the Converter (Example) Frequency Response without Compensator. Gain: T(s) = H(s)GPWM 80 40 (3.0000K,-6.1957) Step4 Read the Gain value (dB) at the fC from 0 the Bode plot, Then put the values to the sheet. -40SEL>> -90 db(v(vout)) 270d 180d 90d Compensator: 0d G @ fc -6.2dB ; read from the simulation result -90d G 2.042 ; compensation gain-180d-270d 10Hz 100Hz 1.0KHz 10KHz 100KHz p(v(vout)) Frequency Tip: To bring cursor to the fc = 3kHz type “ sfxv(3k) ” in Search Command. Cursor Search All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 24
  25. 25. 5 Stabilizing the Converter (Example) • This calculation could be completed by using the Boost Converter Calculator (Excel sheet). • After input all the known parameters, this sheet will suggest the C1, C2, C3, R1, and R2 values.Compensator: fz,double 402Hz ; double zero use to compensate the LC filter peak (resonant) fp1 4181Hz ; a first pole use to compensate an ESR effect fp2 11470Hz ; a second pole use to compensate RHP zero a 8.39E+13 c 3.72E+15 Step5 R C values are suggested, input theCompensator components: values to the elements of compensator. C1 8.259 nF C2 0.795 nF C3 2.826 nF R1 47.9 kW R2 4.9 kW  Please note that the capacitor C value ( from 4 ) needs to be big enough to make fp2 > fp1 for the best result in calculation. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 25
  26. 26. 5 Stabilizing the Converter (Example) Frequency Response with Compensator.Converter parameters RLs L U1 PARAMETERS: {RLs} {L} BOOST_SW v out Vin_min = 2.97 D Vout = 12V ESR Io_max = 1.5A {ESR} Vref = 0.8 Rload Vp = 2.2 1 Vin {Vout/Io_max} {Vin_min} C Rlower = 10k {C} 2 Rupper = 140k L = 6.8u 3 G(s) C2 RLS = 10m 0 {C2} R2 C = 1410u {R2} GAIN1 Rupper ESR = 27m 4 {1/Vp} C1 R1 {Rupper} C3 {C1} {R1} {C3}Type 3 compensator parameters LOL - err 1kH + U2 PARAMETERS: COL ERRAMP 1kF Vref C1 = 8.259n {Vref } Rlower C2 = 795p Input the values, read from {Rlower} Vac C3 = 2.826n the Boost Converter 1Vac R1 = 47.9k Calculator (Excel sheet) 0 0 R2 = 4.9k All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 26
  27. 27. 5 Stabilizing the Converter (Example) Gain and Phase responses after stabilizing 80 Gain: T(s) = H(s)G(s)GPWM 40 (3.0000K,-384.347m) 0 -40 -80 db(v(err)) 270d Phase margin at 3k = 50-(-90)=140 Phase  180d (3.0000K,49.809) 90d 0d -90d SEL>> -270d 10Hz 100Hz 1.0KHz 10KHz 100KHz p(v(err)) Frequency • Phase margin = 140 at 3kHz. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 27
  28. 28. Load Transient Response Simulation (Example) The converter, that have been stabilized, are connected with step-load to perform load transient response simulation.Converter parameters U1 0.2-1.5A step load RLs L {RLs} {L} BOOST_SW v out PARAMETERS: Vin_min = 2.97 D Vout = 12V ESR Io_max = 1.5A {ESR} I1 = 0.2 I1 Vref = 0.8 I2 = 1.5 TD = 1m Vp = 2.2 Vin TR = 10u Rlower = 10k {Vin_min} C TF = 10u {C} PW = 1m Rupper = 140k PER = 1 L = 6.8u RLS = 10m C = 1410u C2 0 {C2} R2 ESR = 27m {R2} GAIN1 Rupper {1/Vp} C1 R1 {Rupper}Type 3 compensator parameters C3 {C1} {R1} {C3} PARAMETERS: - C1 = 8.259n err + C2 = 795p U2 C3 = 2.826n ERRAMP Vref R1 = 47.9k Rlower {Vref } R2 = 4.9k {Rlower} *Analysis directives: .TRAN 0 4ms 0 1u 0 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 28
  29. 29. 5 Stabilizing the Converter (Example) Step-load transient responses after stabilizing 2.0A 0.2-1.5 A step-load 1.0A (1.0222m,1.5000) 0A (0.000,200.000m) -1.0A -2.0A I(I1) 12.10V (2.0485m,12.055) VOUT 12V 12.05V 12.00V 11.95V SEL>> (1.0585m,11.942) 11.90V 0s 0.4ms 0.8ms 1.2ms 1.6ms 2.0ms 2.4ms 2.8ms 3.2ms 3.6ms 4.0ms V(VOUT) Time • The simulation result shows undershoot and overshoot voltages caused by step-load, that are below 120mV or less than 1% of the output. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 29
  30. 30. A. Boost Converter Calculator (Excel sheet) 1/3Boost Converter Calculator (Excel sheet)The following specs are needed to calculate the power stage:Spec: Vin,max 3.63 V ; +10% of 3.3V Vin,min 2.97 V ; -10% of 3.3V Vout 12 V Vout,ripple 0.18 V ; 1.5% ripple value Io,max 1.5 A Io,min 0.2 A All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 30
  31. 31. A. Boost Converter Calculator (Excel sheet) 2/3The following specs are needed to calculate the controller stage: VREF 0.8 V Vp 2.2 V fOSC 300 kHz Rlower 10 kW Rupper 140 kW Dmax 0.75 ; = 1- Vin,min/Vout Dmin 0.70 ; = 1- Vin,max/Vout L> 6.4 uH ; suggested inductor L value L= 6.8 uH ; the selected inductor L value RLs = 10.0 mW ; the selected inductor, series resistance value IL 1.10E+00 A ; calculated inductor ripple current C 20.9 uF ; eq. (7) suggested value C 1410 uF ; the selected capacitor C value ESR  0.027 W ; eq. (9) suggested value ESR = 0.027 W ; the selected capacitor ESR value IC,Rated = 5.48E-01 ; Rated ripple current All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 31
  32. 32. A. Boost Converter Calculator (Excel sheet) 3/3 Type 3 Compensator Calculator Rload,min 8W ; = Vout/Io,min fc < 3440.91Hz ; fC < 0.3 times RHP zero fc = 3000Hz ; the selected fC value Vin,max < 7.38V ; Vin,max suggested value Compensator: G @ fc -6.2dB ; read from the simulation result G 2.042 ; compensation gain ; double zero use to compensate the LC filter peak fz,double 402Hz (resonant) fp1 4181Hz ; a first pole use to compensate an ESR effect fp2 11470Hz ; a second pole use to compensate RHP zero a 8.39E+13 c 3.72E+15 Compensator components: C1 8.259nF C2 0.795nF C3 2.826nF R1 47.9kW R2 4.9kW All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 32
  33. 33. B. Feedback Loop Compensator VOUT VOUT VOUT C2 C2 C1 R2 C1 R1 C1 R1 Rupper Rupper Rupper C3 - FB - FB - FB err err err + + + Rlower Rlower Rlower Vref Vref Vref 0 0 0 0 0 0 Type1 Compensator Type2 Compensator Type3 Compensator • Because the boost converter is a 2nd order system, so the Type3 compensator are needed All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 33
  34. 34. C. Simulation Index Simulations Folder name 1. Frequency Response without a Compensator............................. freq_resp 2. Frequency Response with a Type3 Compensator....................... freq_resp-comp 3. Step-load Transient Response.................................................... step-load Libraries : 1. ..¥boost_sw.lib 2. ..¥erramp.lib Tool : • Boost Converter Calculator (Excel sheet) Boost_Calculator.xls All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 34

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