SIDO converter with variable control time duty...1 SIDO converter with variable control time duty Gunma University. Naoya Shiraishi Yasunori Kobori, Nobukazu Takai, Nobukazu Tsukiji,

Takai Lab.

1

SIDO converter with variable control time duty

Gunma University.

Naoya ShiraishiYasunori Kobori, Nobukazu Takai, Nobukazu Tsukiji,Kotaro Kaneya, Shunsuke Tanaka, Haruo Kobayashi

4S-AVIC2014, Ho Chi Minh, Vietnam, Oct 23 14年10月20日月曜日

OUTLINE 2

• Background and Objective• Conventional Buck-Buck SIDO converter 　and drawback of conventional control method• Proposed control method• Sawtooth wave generator circuit• Simulation results• Conclusions and Future works

14年10月20日月曜日

OUTLINE 3



4Background and Objective

220V AC

12V DC

1.5V DC

converts power-supply voltage for electronic device.

Power Circuit

AC-DC converterAC input-DC output

DC-AC converterDC input-AC output

AC-AC converterAC input-AC output

DC-DC converterDC input-DC output


5

220V AC

12V DC

1.5V DC

Numerous converters used in a single device.

Increases the area of electronic devices.

Converts power-supply voltage for electronic device.

Power Circuit


Background and Objective


Single Inductor

Dual Outputs

6

Buck-Buck SIDO converter

SIDO means・・・Single Inductor Dual Output

S0 S2

S1

LD C2 R2

C1 R1

Vin

Vo1

Vo2IL

Io1

Io2


Miniaturization



7

High Performance

New control method

S0 S2

S1

LD C2 R2

C1 R1

Vin

Vo1

Vo2IL

Io1

Io2

SIDO means・・・Single Inductor Dual Output

Buck-Buck SIDO converter



Single Inductor

Dual Outputs

Miniaturization


OUTLINE 8



　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

Conventional Buck-Buck SIDO converter 9

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　S0 S2

S1

LD C2 R2

C1 R1

Vin

Vo1

Vo2IL

Io1

Io2

S1

S2

S0

IL

ON

OFF ON

OFF

ON ONOFF OFF

Io1 Io2

T1 T2 T3 T4

t

TTo1 To2

Power Stage Timing Chart


　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

10

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　S0 S2

S1

LD C2 R2

C1 R1

Vin

Vo1

Vo2IL

Io1

Io2

S1

S2

S0

IL

ON

OFF ON

OFF

ON ONOFF OFF

Io1 Io2

T1 T2 T3 T4

t

TTo1 To2


Determination ofsupply destinationDetermination of

supply value

Conventional Buck-Buck SIDO converter


　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

11

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　S0 S2

S1

LD C2 R2

C1 R1

Vin

Vo1

Vo2IL

Io1

Io2

S1

S2

S0

IL

ON

OFF ON

OFF

ON ONOFF OFF

Io1 Io2

T1 T2 T3 T4

t

TTo1 To2

ON OFF ON OFF

IL Io1 Io2

IL

Io1

Io2

Load current is determined by this area




　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　

12

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　S0 S2

S1

LD C2 R2

C1 R1

Vin

Vo1

Vo2IL

Io1

Io2

S1

S2

S0

IL

ON

OFF ON

OFF

ON ONOFF OFF

Io1 Io2

T1 T2 T3 T4

t

TTo1 To2

Control time ratio To1:To2 is fixed.




13Drawback of conventional control method

It isn’t possible to work in large load current ratio.

S1

S2

IL Io1Io2 t

To1 To2

Limited by To1

Increase


14

Conventional Proposal

S1

S2

IL Io1Io2 t

To1 To2

Control time ratio is fixed Control time ratio is variable

Operation range will become larger

Proposed method

S1

S2

IL Io1Io2 t

To1 To2


OUTLINE 15



16Proposed control method

+<

<

+

<

+<

+<

+<

+

<

+

Vin

S0

DL

IL

S2

S1 C1 R1Vo1

Vo2

Io1

Io2

comp

comp

comp

C2 R2

SEL

PWMEA

EA

op Vref1

Vref2

6Vo1

sawtooth1

sawtooth2

6Vo2

ControllerSW

sawtooth

PWM1

PWM2

Entire block diagram of the proposed circuit

Power stage

Control stage


17

【Flow of the proposed control method 】

<

+

<

+<

+<

+<

+

<

+

Vo1

Vo2

Vref1

Vref2

6Vo1

6Vo2

SEL

PWMEA

EA

opcomp

sawtooth1

sawtooth2

comp

comp

6VSEL

sawtooth

S1 S2PWM1

PWM2

Block diagram of control circuit

Ⅰ.Acquisition of error voltage ΔVo1,ΔVo2.

Ⅱ.Generation of SEL signal responding to two output voltage error ratio.

Ⅲ.Generation of sawtooth wave with matching the High/Low time width of SEL signal.

Ⅳ.Generation of PWM signal by comparing sawtooth with ΔVo1,ΔVo2.

Proposed control method


18

Ⅰ<

+

<

+<

+<

+<

+

<

+

Vo1

Vo2

Vref1

Vref2

6Vo1

6Vo2

SEL

PWMEA

EA

opcomp

sawtooth1

sawtooth2

comp

comp

6VSEL

sawtooth

S1 S2PWM1

PWM2

【Flow of the proposed control method 】Ⅰ.Acquisition of error voltage ΔVo1,ΔVo2.


Ⅲ.Generation sawtooth wave with matching the High/Low time width of SEL signal.


Proposed control methodBlock diagram of control circuit


19

<

+

<

+<

+<

+<

+

<

+

Vo1

Vo2

Vref1

Vref2

6Vo1

6Vo2

SEL

PWMEA

EA

opcomp

sawtooth1

sawtooth2

comp

comp

6VSEL

sawtooth

S1 S2PWM1

PWM2

Relation between the value of and control time ratio

To1 To2 To1 To2

To1 To1To2 To2

To1 To1To2 To2SEL

SEL

SEL

6VSEL

6VSEL

6VSEL

6Vo1>6Vo2

6Vo156Vo2

6Vo1<6Vo2

t

V





Ⅱ



20

<

+

<

+<

+<

+<

+

<

+

Vo1

Vo2

Vref1

Vref2

6Vo1

6Vo2

SEL

PWMEA

EA

opcomp

sawtooth1

sawtooth2

comp

comp

6VSEL

sawtooth

S1 S2PWM1

PWM2 In case of ΔVo1>ΔVo2

To1 To1To2 To2SEL

6VSEL6Vo1>6Vo2

t

V

sawtooth1

sawtooth2





Ⅲ



21

<

+

<

+<

+<

+<

+

<

+

Vo1

Vo2

Vref1

Vref2

6Vo1

6Vo2

SEL

PWMEA

EA

opcomp

sawtooth1

sawtooth2

comp

comp

6VSEL

sawtooth

S1 S2PWM1

PWM2

t

V

sawtooth1

sawtooth2

6Vo1

6Vo2

PWM1

PWM2

PWM

In case of ΔVo1>ΔVo2





Ⅳ



OUTLINE 22



23Sawtooth wave generator circuit

Ⅲ <

+

<

+<

+<

+<

+

<

+

Vo1

Vo2

Vref1

Vref2

6Vo1

6Vo2

SEL

PWMEA

EA

opcomp

sawtooth1

sawtooth2

comp

comp

6VSEL

sawtooth

S1 S2PWM1

PWM2

Ⅳ





More detail

Block diagram of control circuit


24

sawtooth1 t

SEL To1 To1

<

+

<

+<

+<

+<

+

<

+

Vo1

Vo2

Vref1

Vref2

6Vo1

6Vo2

SEL

PWMEA

EA

opcomp

sawtooth1

sawtooth2

comp

comp

6VSEL

sawtooth

S1 S2PWM1

PWM2

SELSW C

Vc

PeakHold

VddVph

sawtooth1

<

+ PWM1

6Vo1

Internal of sawtooth1

Timing chart

Searches the peak value of sawtooth.

Sawtooth wave generator used in proposal method

Block diagram of control circuitvoltage controlledcurrent source

Sawtooth wave generator circuit


25

sawtooth1 t

SEL To1 To1OFF

SELSW C

Vc

PeakHold

VddVph

sawtooth1

<

+ PWM1

6Vo1

I

Increase

Sawtooth wave generator used in proposal methodTiming chart

ON

Reset

Sawtooth wave is generated.

voltage controlledcurrent source



26

sawtooth1

t

SEL To1 To1

6Vo1

PWM1SEL

SW C

Vc

PeakHold

VddVph

sawtooth1

<

+ PWM1

6Vo1

電圧制御電流源

By comparing ΔVo1 sawtooth,PWM1 is generated.

Sawtooth wave generator used in proposed methodTiming chart


t

V

6Vo1-1

PWM1

6Vo1-26Vo1-max

To1

PWMmax

Relation between value of ΔVo1 and width of PWM


27

タイミングチャート

sawtooth1

t

SEL To1 To1

6Vo1

PWM1

ΔVo1とsawtooth1を比較しPWM1を生成する

SELSW C

Vc

PeakHold

VddVph

sawtooth1

<

+ PWM1

6Vo1

電圧制御電流源

SET : ΔVo1-max = Peak value of sawtooth

Width of PWMmax = Width of To1.



Relation between value of ΔVo1 and width of PWM

t

V

PWM1

6Vo1-maxTo1

PWMmax


28

SELSW C

Vc

PeakHold

VddVph

sawtooth1

<

+ PWM1

6Vo1


sawtooth1 t

SEL To1 To1

Increase of OFF time

Increase of peak value

Timing chart

6Vo1maxsawtooth1PWM1max

IL tIo1max Io1max

To1 To1SEL

Io doesn’t increase.

PWMmax doesn’t increases.



29

SELSW C

Vc

PeakHold

VddVph

sawtooth1

<

+ PWM1

6Vo1

6Vo1maxsawtooth1PWM1max

ILtIo1max Io1max

To1 To1SEL

Searched peak value of sawtooth

For any To1, peak value of sawtooth is constant

PWM1max increases.

Io1max increases.


voltage controlledcurrent source

control

Control of current source



OUTLINE 30



31Simulation Results

+<

<

+

<

+<

+<

+<

+

<

+

Vin

S0

DL

IL

S2

S1 C1 R1Vo1

Vo2

Io1

Io2

comp

comp

comp

C2 R2

SELPWM EA

EA

op Vref1

Vref2

6Vo1

sawtooth1

sawtooth2

6Vo2

ControllerSW

ParameterSchematic diagram of simulation circuit

input voltage:Vin 10V

output voltage:Vo1 5.0V

output voltage:Vo2 4.0V

load current:Io1 5.0A

load current:Io2 0.5A

inductor:L 0.5µH

output capacitor:C 470µF

operating frequency:f 200kHz


32

To1 To2

0

SEL

IL[A]14

To1 To2

t t

Io1=5.0[A] , Io2=0.5[A]

conventional method (control time ratio is fixed) proposal method (control time ratio is variable)

Simulation Results

Waveforms of SEL and IL


33

V[V]

5

4

3

2

1

00 2 4 6 8

t[ms]

Vo1

Vo2

10

Waveform of output voltage

stable


34

5

5.04

4.96

4

4.04

3.96

Vo1[V]

Vo2[V] 3mV

16mV

4 5 t[ms]

Steady state output voltage ripple characteristics

0.1%

0.3%


35

2 3

4

3.96

5

4.96

5.04

Vo1[V]

Vo2[V]

Io1=2.5A Io1=5.0A Io1=2.5A

t[ms]

4.04

18mV

3mV

Load step response characteristics

sufficiently-small


36

5 6

4

3.96

5

4.96

5.04

Io2=0.25A Io2=0.5A

t[ms]

4.04

Vo1[V]

Vo2[V] 3mV

Io2=0.25A

sufficiently-small

Load step response characteristics


To1 To2

37

0

SEL

sawtooth1[V]

IL[A]0

14

To1 To2

0

5

5sawtooth2[V]

tIo1=0.5[A] , Io2=0.5[A] Io1=5.0[A] , Io2=0.5[A]

Peak value of sawtooth wave

peak value is constant


OUTLINE 38



39Conclusions and Future works

◯we have proposed a new control method that works in case of a large load current ratio, and confirmed the basic characteristics.

By varying control time ratio of two converters, we have confirmed the operation of the proposed method in case of the load current ratio

Io1 :Io2 =5.0A:0.5A that is 10:1.

Conclusions

◯Operation in CCM (continuos current mode )◯Operation with a much higher load current ratio

Future works


40


41

To1 To2

Io1Io2

IL

To1 To2

Io1 Io2

IL

CCM動作での従来方式と提案方式の違い

従来方式

提案方式

Duty=0でも多く電流が流れてしまう。電圧が収束しない。


Documents

SIDO converter with variable control time duty...1 SIDO converter with variable control time duty Gunma University. Naoya Shiraishi Yasunori Kobori, Nobukazu Takai, Nobukazu Tsukiji,