1 www.ice77.net 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 = 2kHz VAMPL = 1V VOFF = 0.2V D1 D1N4002 D2 D1N4002 C2 10nF V V Greinacher voltage doubler Time 0s 20ms 40ms 60ms 80ms 100ms 120ms 140ms 160ms 180ms 200ms V(V1:+) V(D2:2) -1.0V 0V 1.0V 2.0V Time domain sweep On the negative cycle of the input waveform, D 1 is forward-biased, D 2 is reverse-biased and C 1 charges. Likewise, with the positive cycle of the input waveform, D 2 turns on, D 1 is turns off and C 1 shares its charge with C 2 . 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.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1 www.ice77.net
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.
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.
2 www.ice77.net
The circuit can be drawn like above:
0
D1D1N4002
D2D1N4002
V
V
C1
10nF
V1
FREQ = 2kHzVAMPL = 1VVOFF = 0.2V
C2
10nF
Alternately, it can be drawn like this:
0
D1D1N4002
D2
D1N4002
C210nF
VV
C1
10nF
V1
FREQ = 2kHzVAMPL = 1VVOFF = 0.2V
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.
3 www.ice77.net
Delon voltage doubler This circuit is also known as a bridge voltage doubler.
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.
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.
6 www.ice77.net
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.
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.
8 www.ice77.net
Voltage tripler circuit I This is a generic circuit that triples an AC input voltage and produces a DC output voltage.
Note: this circuit is very similar to the previous circuit but C4 is referenced to ground.
16 www.ice77.net
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.
The MOSFET has the following characteristics: W=4500nm and L=450nm.
18 www.ice77.net
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.