1. Abstract -- The objective of this paper is to present a family of
PWM dc-dc converters that achieves ZVS (Zero Voltage
Switching) for the main switch and ZCS (Zero Current
Switching) for the auxiliary switch using a new configuration of
the auxiliary circuit cell. It is shown that the proposed auxiliary
circuit cell can be used in all three basic dc-dc converters -
buck, boost and buck-boost - to transform a PWM
hard-switched converter into a low-loss soft-switched
equivalent without affecting operation of the original PWM
converter. The same auxiliary circuit cell can also be used to
implement loss-less switching in other non-isolated or isolated
PWM converter circuits such as Cuk, sepic, flyback or
forward. The auxiliary circuit of the basic converters includes
two additional diodes. These diodes allow clamping of the
voltage across the auxiliary switch. In this paper different
circuit modes of a ZVS PWM buck converter with the
proposed auxiliary circuit are analyzed. The analog circuit
that would be required for generation of the switching pulses
for the main and auxiliary switches is provided. The
experimental results of a 12V, 40W ZVS PWM buck converter
with the proposed auxiliary circuit are presented. It shows that
for the main switch ZVS and for the auxiliary switch ZCS
operations are achieved.
I. INTRODUCTION
The Pulse Width Modulated (PWM) dc-dc convert-
ers are mostly available in three well-known circuit configu-
rations - buck, boost and buck-boost. From these basic
configurations other non-isolated converter circuits - Cuk,
Zeta and Sepic - have evolved possessing some interesting
properties. The isolated dc-dc converters - forward, flyback,
half-bridge, full-bridge and push-pull - are also derived from
the basic circuits but each includes a transformer to provide
isolated output.
In operation of dc-dc converters, whether isolated
or non-isolated, there is a continuous demand to increase the
switching frequency, as that would reduce the sizes of the
passive components. The problem is that with the increase
of switching frequency the switching loss of the power
semiconductor devices also increases, thereby affecting the
efficiency of the converter. This problem can be solved by
implementation of some kind of soft -switching method
where voltage across the device and the current through the
device are not allowed to change simultaneously at the time
of turn-on and turn-off of the switches. The strategies that
have been developed to fulfill this objective are generally
known as zero voltage switching (ZVS) or zero current
switching (ZCS) methods, depending upon which variable is
allowed to vary while maintaining the other at zero. Imple-
mentation of this strategy requires that additional resonant
elements are used along with the core converter circuit, so as
to create oscillations in voltage and current waveforms.
Simultaneously it is also necessary to organize the control
and pulse generation methods in such a way that the
resonant waveforms can be utilized for ZVS or ZCS transi-
tions. There are a few strategies that have evolved over the
years to achieve ZVS or ZCS in power semiconductor
devices.
The conventional resonant converters described in
[1,2] operate at a switching frequency higher than the
resonant frequency of the selected components in order to
achieve ZVS. The shortcomings are that in these converters
the simplicity of PWM control is lost and the installed volt-
apmere of the circuit elements is far higher that the output
volt-ampere.
The ZVS or ZCS operation is achieved in resonant
switch converters, also known as quasi-resonant converters
[3-5], by configuration of each active switch into a resonant
switch module by inclusion of resonant components and
diode. However, compared to a PWM converter it has the
following unfavorable features. The control has to be
achieved by variation of switching frequency. The voltage
and/or current rating of the switching device in quasi
resonant mode of operation is more than in PWM mode of
operation. The ZVS and/or ZCS operation is load
dependent.
The phase modulated full bridge converters
proposed in [6-7] have the following advantages over
conventional resonant converters and resonant switch
converters. These converters can be controlled by phase
modulation method and may not require additional resonant
A New Family of Active Clamp PWM DC-DC
Converters with ZVS for Main Switch and ZCS for
Auxiliary Switch
Souvik Chattopadhyay, Santosh Baratam, Hariom Agrawal
Power Electronics Group
Department of Electrical Engineering,
Indian Institute of Technology Kharagpur,
Kharagpur, India

2. elements as circuit non-idealities can be effectively used to
implement ZVS. However, the asymmetry in ZVS operation
between the two resonant transition modes and significance
of the non-idealities of the circuit elements in ZVS imple-
mentation pose serious design challenges in achieving ZVS
over wide load range.
The auxiliary circuit topologies proposed in
various zero voltage transition (ZVT) converters [8-13]
implement loss-less switching in the main switching device
while retaining the variable-duty-ratio-constant-switching-fr
equency control of PWM converters intact. These converters
include an auxiliary switch that initiates resonance in the
added circuit elements so as to achieve ZVS of the main
switch. However, in [8] the switching losses occur for the
auxiliary switches.
In the ZVS PWM active-clamping converters
proposed in [9], the ZVS condition is dependent on load
current and the active switch volt-ampere rating needs to be
more than that of PWM switches. In the ZVT converters
proposed in [10-12], the turn-off of the auxiliary switch is
lossy and control is complicated.
The family of auxiliary switch converters proposed
in [13] has addressed the above mentioned problems. In
these converters it is possible to achieve ZVS for the main
switch and ZCS for the auxiliary switch by using a coupled
inductor in the auxiliary circuit cell. The circuit configura-
tion for a ZVS PWM buck converter is shown in Fig. 1. One
of the consequences of using a coupled inductor is that the
voltage rating of the auxiliary switch needs to be more than
the input voltage. It can also be noted that due to the
coupled inductor the operation of the basic dc-dc converter
is not completely independent of the operation of the auxil-
iary circuit.
In this paper a new class of ZVS-PWM dc-dc
converters is proposed based on a new configuration of the
auxiliary circuit. The auxiliary switch enables ZVS transi-
tion of the main switch while it’s own switching transitions
are characterized by ZCS. A ZVS-PWM buck converter of
the proposed configuration is shown Fig. 2(a) and the basic
auxiliary circuit cell, consisting of two capacitors, one
inductor and two diodes, is shown in Fig, 2(b). Along with
this auxiliary circuit cell two additional diodes act as voltage
clamp for the auxiliary switch. The important feature of this
class of converters is that the operations of the basic dc-dc
converter and the auxiliary circuit are completely independ-
ent of each other.
This paper has been organized as follows. Section
II describes the proposed circuit configuration for a sample
ZVS-PWM buck converter. Section III presents the circuit
analysis of the sample converter in the form of equations of
the auxiliary circuit voltage and current waveforms during
different subintervals of operation. In section IV it is shown
that this configuration is also applicable for other isolated
and non-isolated dc-dc converters topologies. Section V
presents the experimental results of a 40W, 100 kHz buck
converter using the proposed auxiliary circuit cell. Section
VI gives the conclusion and lists the references.
II. DESCRIPTION OF PROPOSED CIRCUIT
The process of loss-less switching has been
described for the specific example of a PWM buck converter
that uses the proposed auxiliary circuit as shown in Fig. 2(a).
The circuit waveforms are shown in Fig. 3.
The auxiliary switch is turned-on with theQa
initial condition that the main switch is off and the diodeQ
is conducting. The proposed circuit configuration uses aD
series capacitor that in combination with the auxiliaryCa2
inductor develops resonance in the auxiliary circuit. TheLa
Q
Ca1
L
D
RC
Vg
Buck Converter
Qa
La
D1a
Lc
Auxiliary circuit cell
Fig. 1. ZVS-PWM buck converter with auxiliary circuit cell proposed in
[13]
Q
L
D R
C
Ca2
Vg
Buck Converter
Vo
Qa
Ca1
D1a
La
D2a
Dc1
Dc2
Auxiliary circuit
Basic auxiliary circuit cell
Qa
Ca1
D1a
La
D2a
Ca2
Fig. 2(a)
Fig. 2(b)
IL
i
La
V
Ca1
V
Ca2
Fig. 2 (a). ZVS-PWM buck converter with the proposed auxiliary circuit
(b). Basic auxiliary circuit cell

3. inductor current first turns-off the diode and thenD
discharges the capacitor across the main switch and as aCa1
result the subsequent turn-on of it satisfies ZVS. The induc-
tor current then reverses it direction and as a result when it
goes through zero ZCS of the auxiliary switch is achieved. It
may be observed that the proposed circuit configuration has
two extra diodes and compared to [13]. isD2a Dc2 D2a
required to maintain the continuity of the inductor current in
the opposite direction during resonance and for theDc2
discharge of the resonant capacitor by the load current. The
capacitor is charged during the resonant cycle fromCa2
initial value of zero to some negative value and it is
discharged by the load current of the buck converter just
after the main switch is turned-off and before the diode D
starts to conduct. The capacitor is selected with theCa1
objective that turn-off of is ZVS as well with a definedQ
rate of change of voltage. The proposed topology also
includes another diode , that though is not a basicDc1
requirement of the topology but improves the operation
nevertheless, as it clamps the voltage across the auxiliary
switch by providing continuity to the resonant inductor
current. In the inductor this current is developed due to the
reverse recovery current of the diode that conductsD2a
during the negative cycle of the inductor current.
III. CIRCUIT ANALYSIS
In the following analysis all the switching devices
and the passive components are considered to be ideal. The
variables used in this analysis are defined in Fig. 2. The
circuit waveforms are sketched qualitatively in Fig. 3. The
entire switching period has been divided into various
subintervals. At any instant the mode of operation of the
converter is decided by the equivalent circuit.
Mode 0: The equivalent circuit is shown in Fig. 4. Both Q
and are in off state.Qa
(1)iD = IL
Mode 1: The equivalent circuit is shown in Fig.5. The
auxiliary SWITCH is turned-on at . At theQa t = 0 t = T1
current through the auxiliary inductor becomes equal toiLa
the load current and the diode stops conduction.IL D
(2)iLa(t) = Vg
Ca2
La
sin 1t
(3)vCa2(t) = Vg(1 − cos 1t)
(4)vCa1(t) = Vg
(5)1 = 1
LaCa2
Qa
Q
IL
iLa
v
c1
v
c2
T1
T2
T3
T4
i
Dc2
t
t
t
t
t
ON
ON ON
Fig. 3. Key waveforms of the proposed ZVS-PWM buck converter

4. (6)T1 = 1
1 sin−1
(
IL
Vg
La
Ca2
)
Mode 2: The equivalent circuit is shown in Fig.6. The diode
is off and the current through the capacitor is equalD Ca1
to . This mode ends at when .iLa − IL t = T2 VCa1(T2) = 0
This can be solved from
(7)iLa(t) = Vg
Ca1||Ca2
La
cos( 1T1)sin 2t + IL cos 2t
(8)2 = 1
La(Ca1||Ca2)
Since the above equations can beCa1 << Ca2
approximated as
(9)iLa(t) = Vg
Ca1
La
cos( 1T1)sin 2t + IL cos 2t
(10)2 = 1
LaCa1
(11)
vCa1(t) = Vg(1 − cos 1T1) + Vg cos( 1T1)cos 2t
− IL
La
Ca1
sin 2t
(12)vCa2(t) = Vg[1 − cos( 1T1)] = vCa2(T1)
Mode 3, Mode 4 and Mode 5: In Mode 3 the body
diode of the main switch conducts. Subsequently isQ Q
turned-on under ZVS and the circuit enters into Mode 4.
Mode 4 ends when at , . Under that conditiont = T3 iLa = 0
the auxiliary switch turns-off under ZCS along with the
Ca1
D1a
La L
D
RC
Ca2
D2a
Dc1
Dc2
Vg
IL
ID
ca2
ca1Qa
off
Q
off
initial state
mode 0
i
La v
v
Fig. 4 : Mode 0 equivalent circuit
Ca1
D1a
La L
D
RC
Ca2
D2a
Dc1
Dc2
Vg
IL
ID
Vca2
Vca1
Ila
Qa
Turned-on
Q off
mode 1
Fig. 5 : Mode 1 equivalent circuit
Ca1
D1a
La L
RC
Ca2
D2a
Dc1
Dc2
Vg
IL
Vca2
Vca1
Ila
mode 2
Fig. 6 Mode 2 equivalent circuit
Ca1
D1a
La L
RC
Ca2
D2a
Dc1
Dc2
Vg
IL
Vca2
Vca1
Ila
ZCS
Turn-off
Qa
mode 5
Fig. 7 Mode 3, 4 and 5 equivalent circuit
Ca1
D1a
La L
RC
Ca2
D2a
Dc1
Dc2
Vg
IL
Vca2
Vca1 ZVS Turn offQ
At the end of this mode
the initial state is reached
mode 7
(actual)
i
Dc2
Fig. 8 : Mode 7 equivalent circuit
Ca1
D1a
La L
RC
Ca2
Dc1
Dc2
Vg
IL
Vca2
Vca1
Ila
mode 5(ii)
Vg
mode 5
Voltage
clamp
Fig. 9 : Mode 5(ii) equivalent circuit
Ca1
D1a
La L
RC
Ca2
D2a
Dc1
Dc2
Vg
IL
Vca2
Vca1
Ila
mode 5(i)reverse
recovery
current
Fig. 9(a) : Mode 5(i) equivalent circuit

5. diode . In Mode 5 the current in the inductor is negativeDa1
and it flows through the diode . The equivalent circuit isDa2
shown in Fig.7. This mode ends when at , againt = T4 iLa
reaches . The differential equations governing and0 iLa vCa2
are the same in all these modes.
(13)iLa(t) = −vCa2(T1)
Ca2
La
sin 1t + ILa(T2)cos 1t
(14)vC2(t) = IL
Ca2
La
sin 1t + vCa2(T1)cos 1t
Mode 6: This mode is the on state of the buck converter.
The switch is on and it carries the load current .Q IL
Mode 7: The equivalent circuit is shown in Fig.8. This mode
starts when is turned-off and begins to conduct. TheQ Dc2
load current is shared between and and theIL Ca1 Ca2
turn-off of is ZVS. At the end of this modeQ vCa2(T5) = 0
and the buck converter diode begins to conduct and theD
circuit returns back to Mode 0.
(15)vC2(t) = VC2(T4) − IL
Ca2
Ca1+Ca2
t
Mode 5(i) and Mode 5(ii): These are two
intermediate modes between Mode 5 and Mode 6 in a
practical power converter and should not exist if we assume
that all the diodes used in this topology are ideal. In Mode
5(i), shown in Fig. 9(a), the reverse recovery current of D2a
flows through . In Mode 5(ii) conducts as it providesLa Dc2
a path for the inductor current developed during the reverse
recovery of the diode . The equivalent circuit is shownD2a
in Fig.9(b). As a result the voltage across gets clampedQa
to the maximum value of . From Mode 5(ii) it wouldVg
return to Mode 5 during the gradual decaying of the reverse
recovery current and eventually the circuit moves to Mode
6. The auxiliary circuit boost and buck-boost converters are
shown in Fig. 10 and Fig. 11 respectively.
Q
L
D
CVg
Auxiliary
circuit
R D2aCa1
Ca2
Dc1
Dc2
Qa
La D1a
Boost Converter
Fig. 10. ZVS-PWM boost converter with the proposed auxiliary circuit
Ca1
Buck-Boost Converter
Q
D
L C
Vg R
D2a Ca2
Dc1 Dc2
Qa
La
D1a
Auxiliary circuit
Fig. 11 ZVS-PWM buck-boost converter with the same auxiliary circuit
Fig. 12 : ZVS-PWM Cuk converter with the auxiliary circuit
D C2 RQ
L
Vg
C1
Auxiliary
circuit
D2aCa1
Ca2
Qa
La D1a
Fig. 13 : ZVS-PWM flyback converter with the auxiliary circuit
D
R
Auxiliary
circuit
D2a
Ca1
Ca2
Qa
La D1a
C
Q
L
Vg
VCa2
Fig. 14 : ZVS_PWM forward converter with the auxiliary circuit
Auxiliary
circuit
D2aCa1
Ca2
Qa
La D1a
Q
L
Vg
D
C
R
Tx
VCa2 V
Qa

6. IV. ISOLATED AND NON-ISOLATED
ZVS-PWM CONVERTERS
It is possible to use the same auxiliary circuit cell,
shown in Fig. 2(b), to construct equivalent ZVS-PWM
topologies for other isolated and non-isolated converters
such as Cuk, sepic, flyback or forward. A ZVS-PWM Cuk
converter is shown in Fig. 12. A ZVS-PWM flyback
converter is shown in Fig. 13. and a ZVS-PWM forward
converter is shown in Fig. 14. Key waveforms of the
ZVS-PWM forward converter is shown in Fig. 15. It may
be noted that unlike the buck converter example discussed
earlier clamp and discharge diodes and can not beDc1 Dc2
used. Therefore the initial voltage of the capacitor is notVc2
zero but . As a result the maximum voltage across theVc
auxiliary switch is also more in these topologies by an
amount .Vc
V. EXPERIMENTAL RESULTS
A ZVS-PWM buck converter is12V,40W
designed with the auxiliary circuit proposed in this paper to
test ZVS operation of the main switch and ZCS operation of
the auxiliary switch.
The gate pulses of the main and auxiliary switches
are generated using standard integrated circuit (IC)
components. The block diagram of the analog control circuit
is shown in Fig. 16. A general purpose PWM controller IC
UC3526A is used to establish the basic PWM mode of
operation. A monostable multivibrator IC CD4528B, that is
triggered on the rising edge of the PWM signal, is used to
produce the switching signal for the auxiliary switch. The
time duration is set to be greater than .Ta T1 + T2 + T3
Similarly another monostable multivibrator is used to
produce a pulse of width that is slightly greater thanTb
. The falling edge of this pulse triggers oneT1 + T2
monostable multivibrator and produces the SET pulse of the
SR F/F implemented using CD4013B. The RESET pulse of
the SR F/F is produced by the falling edge of the original
PWM pulse triggering another monostable multivibrator.
Subsequently the outputs for the main and auxiliary switches
are interfaced to the actual gates of the MOSFETs using
high frequency isolation transformer and MOSFET driver
IC UCC27322.
The design details of the power circuit are as
follows:
(1) buck converter : ; ; ;L = 25 H C = 100 F R = 3.5
; ; ; : IRF640; : MURFS = 100 kHz D = 0.32 Vg = 48V Q D
405.
(2) auxiliary circuit: ; ;La = 0.7 H Ca1 = 4.7 nF
; and : MUR 405; :Ca2 = 100 nF D1a,D2a,Dc1 Dc2 Qa
IRF640.
The experimental results are presented in Fig. 17
and Fig. 18 for a ZVS-PWM buck converter.12V,40W
The operation of the converter at a switching frequency of
is demonstrated in Fig. 17(a) and Fig. 17(b) with100 kHz
Qa
Q
IL
iLa
v
c1
v
c2
T1
T2
T3
T4
t
t
t
t
t
ON
ON ON
Fig.15 Key waveforms of the proposed of ZVS forward converter
tVc
Vg+VcV
Qa

7. representative waveforms at two different time scales - Ch1: gate pulse for , Ch2: gate pulse for , Ch3: currentQa Q
Monostable I
(Ta)
PWM
I C
Ex:
UC3526AN
Monostable II
(Tb)
CD 4528
CD 4528
SR F/F
Switching pulses for auxiliary MOSFET Qa
Monostable III
(Td)
CD 4528
CD4013
Monostable IV
(Td)
CD 4528
PWM Pulses
R
S
Switching Pulses
for main MOSFET Q
Ta
Tb
QTb
Qa
Fig. 16. Block Diagram of Generation of Switching Pulses for Main and Auxiliary Switch:
Fig. 17 (a). ZVS-PWM buck converter with representative waveforms
Ch1: gate pulse for , Ch2: gate pulse for , Ch3: current throughQa Q
resonant inductor , scale - 5A/8V Ch4: voltage across the diodeLa (iLa)
D
Fig. 17 (b). ZVS-PWM buck converter with representative waveforms
Ch1: gate pulse for , Ch2: gate pulse for , Ch3: current throughQa Q
resonant inductor , scale - 5A/8V Ch4: voltage across the diodeLa (iLa)
D
Fig. 18 (a). ZVS-PWM buck converter with representative waveforms
Ch1: gate pulse for , Ch2: current through resonant inductor ,Q La (iLa)
scale - 5A/8V, Ch3: voltage across the bulk resonant capacitor Ca2(VCa2)
Ch4: voltage across the diode .D
Fig. 18 (b). ZVS-PWM buck converter with representative waveforms
Ch1: gate pulse for , Ch2: current through resonant inductor ,Q La (iLa)
scale - 5A/8V, Ch3: voltage across the bulk resonant capacitor Ca2(VCa2)
Ch4: voltage across the diode .D

8. through resonant inductor ,scale - 5A/8V, Ch4:La (iLa)
voltage across the diode . Fig. 18(a) and Fig. 18(b) showD
the following waveforms at two different time scales - Ch1:
gate pulse for , Ch2: current through resonant inductorQ La
, scale - 5A/8V, Ch3: voltage across the bulk resonant(iLa)
capacitor Ch4: voltage across the diode .Ca2(VCa2) D
These waveforms prove that in the proposed ZVS-PWM
buck converter the main MOSFET operates with ZVSQ
and the auxiliary MOSFET operates with ZCS.Qa
The measured steady state efficiency of the
designed prototype converter at output is . The40W 82 %
100 kHz ZVS-PWM buck converter prototype (40W, 12V)
is shown in Fig. 19.
VI. CONCLUSION
In this paper a new family of ZVS-PWM dc-dc converters is
proposed. The proposed circuit retains all the advantages -
such as constant switching frequency variable duty ratio
control - of hard-switched PWM converters. At the same
time by using a new configuration of the auxiliary circuit
cell these converters achieve ZVS for the main switch and
ZCS for the auxiliary switch. The auxiliary circuit cell
consists of one resonant inductor, two resonant capacitors,
two diodes and one active switch (MOSFET). This core
circuit module can be used in all isolated and non-isolated
topologies - buck, boost, buck-boost, Cuk, flyback, forward
etc. - to convert the hard-switched topology into the
corresponding ZVS-PWM equivalent. It may be noted that
in buck, boost and buck-boost converters use of two
additional diodes reduce the voltage stress across the
auxiliary device. One important feature for this type of
ZVS-PWM converters is that the auxiliary circuit and the
main dc-dc converter operate independently. Different
modes of operation of the proposed circuit are analyzed.
Experimental results obtained from a 12V, 40W buck
converter prototype prove validity of the proposed
configuration of ZVS-PWM dc-dc converters.
REFERENCES
N. Lakshminarasamma and V. Ramanarayanan, “A Family of
Auxiliary Switch ZVS-PWM DC-DC Converters with Coupled
Inductor” , IEEE Transactions on Power Electronics, vol. 22, no. 5,
pp. 2008-2017, Sept. 2007.
[13]
G. Moschopoulos, P. Jain, “A zero voltage transition boost
converter employing a soft switching auxiliary circuit with reduced
conduction losses,” IEEE Trans. Power Electron., vol.19, no. 1,pp.
130-139, Jan. 2004.
[12]
Y. Xi and P. Jain, “A forward converter topology employing a
resonant auxiliary circuit to achieve soft switching and power
transformer resetting,” IEEE Trans. Ind. electron., vol. 50, no.1, pp.
132-140, Feb. 2003.
[11]
G. Moschopoulos, P. Jain, Y. Liu, and G. Joos, “ A zero-voltage
switched PWM boost converter with an energy feedforward
auxiliary circuit,” IEEE Transactions on Power Electronics, vol. 14,
no. 4, pp. 653-662, Jul. 1999.
[10]
C. Manoel C. Duarte and I. Barbi,” A family of ZVS-PWM active
clamping dc-to-dc converters: Synthesis, Analysis and
Experimentation,” in Proc. INTELEC, 1995, pp.502-509.
[9]
G. Hua, C,S. Leu, and F.C. Lee, ‘Novel zero voltage transition
PWM converter,” IEEE Transactions on Power Electronics, vol. 9,
no.2,pp. 213-219, Mar. 1994.
[8]
R. Ayyanar and N. Mohan, “Novel soft-switching dc-dc converter
with full ZVS-range and reduced filter requirement - Part I :
regulated output applications,” IEEE Transactions on Power
Electronics, vol. 16, no. 2, pp. 184-192, March 2001.
[7]
J.A. Sabate, V. Vlatkovic, R. b. Ridley, F.C. Lee and B. H. Cho,
“Design considerations for high-voltage high-power full-bridge
zero-voltage-switched PWM converters,” in Proc. IEEE Appl.
Power Electron. Conf., 1990, pp. 275-284.
[6]
W. A. Tabisz and F.C.Y. Lee, “Zero-voltage-switching
multiresonant technique - a novel approach to improve performance
of high- frequency quasi-resonant converters,” IEEE Transactions
on Power Electronics, vol. 4, no.4,pp. 450-458, Oct. 1989.
[5]
T. Zheng, D. Y. Cheng, and F.C. Lee, “Variation of quasi-resonant
dc-dc converter topologies,” in Proc. PESC, 1986, pp. 381-392.
[4]
Fred. C. Lee, “Zero voltage switching quasi resonant converters ,”
US Patent 4720668, Jan. 19, 1988
[3]
A. K.S. Bhat and S. B. Dewan, “ Analysis and design of a high
frequency resonant type converter using LCC type commutation,”
in Conf. Rec. 1986 IEEE Industry Applications Society Annual
Meeting, 1986, pp. 657-663.
[2]
R.L. Steigerwald, “High frequency resonant transistor dc-dc
converters,” IEEE Trans. Ind. Electron., vol. IE-31, pp. 181-191,
May 1984
[1]
Fig. 19. 100 kHz ZVS-PWM buck converter prototype (40W, 12V)