ac/dc voltage multipliers

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Voltage multipliers Voltage multipliers boost an AC or DC input voltage and produce a higher DC output voltage. AC/DC voltage multipliers These circuits accept an AC input voltage and produce a DC output voltage. Greinacher voltage doubler This circuit is named after Swiss physicist Heinrich Greinacher who invented the circuit in 1913.

0

C1

10nF

V1

FREQ = 2kHzVAMPL = 1VVOFF = 0.2V

D1

D1N4002

D2

D1N4002

C2

10nF V

V

Greinacher voltage doubler

Time

0s 20ms 40ms 60ms 80ms 100ms 120ms 140ms 160ms 180ms 200msV(V1:+) V(D2:2)

-1.0V

0V

1.0V

2.0V

Time domain sweep

On the negative cycle of the input waveform, D1 is forward-biased, D2 is reverse-biased and C1 charges. Likewise, with the positive cycle of the input waveform, D2 turns on, D1 is turns off and C1 shares its charge with C2. The voltage at the output gradually builds up and reaches a value that is not exactly twice the value of the input because of the voltage drop of the diodes which are not ideal.

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The circuit can be drawn like above:

0

D1D1N4002

D2D1N4002

V

V

C1

10nF

V1


C2

10nF

Alternately, it can be drawn like this:

0

D1D1N4002

D2

D1N4002

C210nF

VV

C1

10nF

V1


The second way of drawing the Greinacher voltage doubler reaveals two important blocks that compose the circuit: C1 and D1 in the red box is an unbiased positive clamp or Villard clamp whereas D2 and C2 in the blue box is a peak detector. The first circuit shifts the input up and the second filters the sinusoidal producing a pseudo-DC signal. Note: regardless of how the circuit is drawn, the output is taken at the output of the peak detector, that is to say at the node where D2 and C2 meet. Note: a voltage doubler has 2 diodes and 2 capacitors.

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Delon voltage doubler This circuit is also known as a bridge voltage doubler.

0

V1


D1

D1N4002

D2

D1N4002

C2

10nF

C1

10nF

V

V-

V+

Delon voltage doubler

Time

0s 20ms 40ms 60ms 80ms 100ms 120ms 140ms 160ms 180ms 200msV(D2:2) V(D1:2,C2:1)

-1.0V

0V

1.0V

2.0V

Time domain sweep

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Boost converter with voltage doubler (positive) This circuit combines a Boost converter and a voltage doubler to generate a high positive output voltage. This circuit delivers a relatively small output current and it has a small input inductor so it operates in DCM.

D1

MUR120

D2MUR120

D3

MUR120

0

C5

1uF

R45m

M1

IRFP151

L1

3.3uH

1 2

00 0

I1

10mAdc

V2

TD = 1ns

TF = 10nsPW = 528nPER = 2us

V1 = 0V

TR = 10ns

V2 = 5V

V1

TD = 1ns

TF = 10nsPW = 10mPER = 20ms

V1 = 0V

TR = 2ms

V2 = 6V

R2

20m

0

C1

10uF

R1

10m

C2

100nF C4

1uF

0

I

V

VV

R35m

Boost converter with voltage doubler (positive)

Time

0s 0.5ms 1.0ms 1.5ms 2.0ms 2.5ms 3.0ms 3.5ms 4.0ms 4.5ms 5.0ms 5.5ms 6.0ms 6.5ms 7.0msV(V1:+) V(D1:2) V(I1:+)

0V

20V

40V

55V

Time domain sweep

The input to the Boost circuit is 6V and the output is 50V. The voltage doubler ups the voltage from 25V to 50V at 10mA for 500mW.

Time

6.980ms 6.982ms 6.984ms 6.986ms 6.988ms 6.990ms 6.992ms 6.994ms 6.996ms 6.998ms 7.000msV(I1:+)

49.938V

50.000V

50.063V

I(L1)-1.0A

0A

1.0A

SEL>>

Inductor current and output voltage

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The load is a relatively low 10mA of current so the circuit operates in DCM and this can be seen by inspecting the inductor current which peaks around 1A, the same peak current seeing by the MOSFET. The advantage of this circuit is that the addition of the voltage double reduces the need for a large duty cycle for the Boost converter while limiting the voltage at the switch node in order to protect the MOSFET from excessive voltage. Note: D1 is the output diode of the Boost converter. C2, D2, D3 and C4 belong to the voltage doubler.

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Boost converter with voltage doubler (negative) This circuit combines a Boost converter and a voltage doubler to generate a high negative output voltage. This circuit delivers a relatively small output current and it has a small input inductor so it operates in DCM.

D4MUR120

D1

MUR120

D2MUR120

D3

MUR120 V

VV

I

0

C5

1uF

R45m

M1

IRFP151

C6

100nF

0

L1

3.3uH

1 2

00 0

V2

TD = 1ns

TF = 10nsPW = 729nPER = 2us

V1 = 0V

TR = 10ns

V2 = 5V

V1

TD = 1ns

TF = 10nsPW = 10mPER = 20ms

V1 = 0V

TR = 2ms

V2 = 6V

R2

20m

0

C1

10uF

R1

10m

C2

100nF C4

1uF

I1

10mAdc

0

R35m

Boost converter with voltage doubler (negative)

Time

0s 1ms 2ms 3ms 4ms 5ms 6ms 7ms 8ms 9ms 10msV(V1:+) V(C5:2) V(D3:1)

-40V

-20V

-0V

-55V

10V

Time domain sweep

The input to the Boost circuit is 6V and the output is -50V. The voltage doubler ups the voltage from -25V to -50V at 10mA for 500mW.

Time

9.980ms 9.982ms 9.984ms 9.986ms 9.988ms 9.990ms 9.992ms 9.994ms 9.996ms 9.998ms 10.000msV(D3:1)

-50.063V

-50.000V

-49.938V

I(L1)-1.0A

0A

1.0A

SEL>>

Inductor current and output voltage

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The load is a relatively low 10mA of current so the circuit operates in DCM and this can be seen by inspecting the inductor current which peaks around 1A, the same peak current seeing by the MOSFET. The advantage of this circuit is that the addition of the voltage double reduces the need for a large duty cycle for the Boost converter while limiting the voltage at the switch node in order to protect the MOSFET from excessive voltage. Note: D1 is the output diode of the Boost converter. C2, D2, D3 and C4 belong to the voltage doubler.

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Voltage tripler circuit I This is a generic circuit that triples an AC input voltage and produces a DC output voltage.

V1


C1

10nF

C2

10nF

C3

10nF

0

D1

D1N4002D3D1N4002

D2D1N4002

V

V

Voltage tripler circuit I

Time


-1.0V

0V

1.0V

2.0V

3.0V

Time domain sweep

Note: the diodes alternate in direction and the capacitors alternate in position.

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V1


C1

10nF

C2

10nF

C3

10nF

0

D1

D1N4002D3D1N4002

D2D1N4002

V

V


V1


C1

10nF

C2

10nF

0

D1

D1N4002D2D1N4002

D3

D1N4002

C310nF

VV

Otherwise, it can also be drawn like this:

V1


C1

10nF

C2

10nF

C3

10nF

0

D1

D1N4002

D3

D1N4002

D2D1N4002

VV

Note: a voltage tripler has 3 diodes and 3 capacitors.

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Voltage tripler circuit II This is a generic circuit that triples an AC input voltage and produces a DC output voltage.

V1


C1

10nF

C2

10nF

C3

10nF

0

D1

D1N4002

D3

D1N4002

D2D1N4002

VV

Voltage tripler circuit II

Time


-1.0V

0V

1.0V

2.0V

3.0V

Time domain sweep

Note: this circuit is very similar to the third version of the previous circuit but C3 is referenced to ground.

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Greinacher voltage quadrupler I This circuit is a combination of two Greinacher voltage doublers connected in series.

0

C1

10nF

V1


D1

D1N4002

D2

D1N4002

C2

10nF

C3

10nF

D3

D1N4002

D4

D1N4002

C4

10nF V

V

Greinacher voltage quadrupler I

Time

0s 20ms 40ms 60ms 80ms 100ms 120ms 140ms 160ms 180ms 200msV(C1:1) V(D4:2)

0V

2.0V

4.0V

-1.0V

Time domain sweep

Note: the diodes alternate in direction and the capacitors alternate in position.

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0

C1

10nF

V1


D1

D1N4002

D2

D1N4002

C2

10nF

C3

10nF

D3

D1N4002

D4

D1N4002

C4

10nF V

V


VV

0

C1

10nF

V1


D1

D1N4002

D2

D1N4002

C2

10nF

C3

10nF

D3

D1N4002

D4

D1N4002

C410nF

Note: a voltage quadrupler has 4 diodes and 4 capacitors.

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Greinacher voltage quadrupler II This circuit is a combination of two Greinacher voltage doublers placed on top of each other.

0

V1


D1

D1N4002

D4

D1N4002

C3

10nF

C2

10nF

C1

10nF

D2

D1N4002

D3

D1N4002

C4

10nF V-

V+V

Greinacher voltage quadrupler II

Time

0s 20ms 40ms 60ms 80ms 100ms 120ms 140ms 160ms 180ms 200msV(C1:1) V(C2:1,C3:1)

0V

2.0V

4.0V

-1.0V

Time domain sweep

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Voltage quadrupler circuit I This is a generic circuit that quadruples an AC input voltage and produces a DC output voltage.

0

V1


C1

10nF

C3

10nF

C2

10nF

C4

10nF

D1

D1N4002

D2

D1N4002

D3

D1N4002

D4

D1N4002 VV

Voltage quadrupler circuit I

Time

0s 0.1s 0.2s 0.3s 0.4s 0.5s 0.6s 0.7s 0.8s 0.9s 1.0sV(V1:+) V(C3:2)

0V

2.0V

4.0V

-1.0V

Time domain sweep

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Voltage quadrupler circuit II This is a generic circuit that quadruples an AC input voltage and produces a DC output voltage.

0

V1


C1

10nF

C3

10nF

C2

10nF

C4

10nF

D1

D1N4002

D2

D1N4002

D3

D1N4002

D4

D1N4002 VV

Voltage quadrupler circuit II

Time

0s 0.1s 0.2s 0.3s 0.4s 0.5s 0.6s 0.7s 0.8s 0.9s 1.0sV(V1:+) V(C4:2)

0V

2.0V

4.0V

-1.0V

Time domain sweep

Note: this circuit is very similar to the previous circuit but C4 is referenced to ground.

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DC/DC voltage multipliers These circuits accept a DC input voltage and produce a DC output voltage. Dickson voltage tripler I This circuit is a modification of the Greinacher voltage multiplier. It uses two out-of-phase signals to triple the input voltage. This is the diode implementation of the circuit.

C1

1nF

C2

1nF

C3

1nF

D1

D1N4001

D2

D1N4001

D5

D1N4001

0

V1

2Vdc

0

0

V2

TD = 1ns

TF = 10nsPW = 4.5usPER = 10us

V1 = 0V

TR = 10ns

V2 = 2V

0

V3

TD = 5us


V1 = 0V

TR = 10ns

V2 = 2V

P1 P2

P1 P2

V

VV

V

Dickson voltage tripler I

Time

0s 1ms 2ms 3ms 4ms 5ms 6ms 7ms 8ms 9ms 10msV(D1:1) V(P1) V(P2) V(D5:2)

0V

2.0V

4.0V

6.0V

Time domain sweep

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Dickson voltage tripler II This is the MOSFET implementation of the previous circuit.

C1

100nF

C2

100nF

C3

100nF

0

V1

2Vdc

0

0

V2

TD = 1ns


V1 = 0V

TR = 10ns

V2 = 2V

0

V3

TD = 5us


V1 = 0V

TR = 10ns

V2 = 2V

P1 P2

P1 P2

Q1RCX200N20

1

2

3

Q2RCX200N20

1

2

3

Q3RCX200N20

1

2

3

V

VV

V

Dickson voltage tripler II

Time

0s 1ms 2ms 3ms 4ms 5ms 6ms 7ms 8ms 9ms 10msV(V1:+) V(P1) V(P2) V(Q3:SOURCE)

-1.0V

0V

1.0V

2.0V

3.0V

Time domain sweep

The MOSFET has the following characteristics: W=4500nm and L=450nm.

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Dickson voltage quadrupler I This circuit is a modification of the Greinacher voltage multiplier. It uses two out-of-phase signals to quadruple the input voltage. This is the diode implementation of the circuit.

C1

1nF

C2

1nF

C3

1nF

D1

D1N4001

D2

D1N4001

D5

D1N4001

V1

2Vdc

0

0

V2

TD = 1ns


V1 = 0V

TR = 10ns

V2 = 2V

0

V3

TD = 5us


V1 = 0V

TR = 10ns

V2 = 2V

P1 P2

P1 P2

C4

1nF

D6

D1N4001

P1 0

V V

Dickson voltage quadrupler I

Time

0s 1ms 2ms 3ms 4ms 5ms 6ms 7ms 8ms 9ms 10msV(D1:1) V(D6:2)

2.0V

4.0V

6.0V

8.0V

Time domain sweep

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Dickson voltage quadrupler II This is the MOSFET implementation of the previous circuit.

C1

100nF

C2

100nF

C3

100nF

V1

2Vdc

0

0

V2

TD = 1ns


V1 = 0V

TR = 10ns

V2 = 2V

0

V3

TD = 5us


V1 = 0V

TR = 10ns

V2 = 2V

P1 P2

P1 P2

Q1RCX200N20

1

2

3

Q2RCX200N20

1

2

3

Q3RCX200N20

1

2

3

C4

100nF

0

Q4RCX200N20

1

2

3

P1

V

V V

V

Dickson voltage quadrupler II

Time

0s 1ms 2ms 3ms 4ms 5ms 6ms 7ms 8ms 9ms 10msV(Q1:GATE) V(P1) V(P2) V(C4:2)

-4.0V

-2.0V

0V

2.0V

4.0V

Time domain sweep

The MOSFET has the following characteristics: W=4500nm and L=450nm.

ac/dc voltage multipliers

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