Development Board
EPC9065
Quick Start Guide
EPC2007C, EPC8010
6.78 MHz, High Power ZVS Class-D Development Board
QUICK START GUIDE
EPC9065
DESCRIPTION
The EPC9065 is a high efficiency, Zero Voltage Switching (ZVS) differential
mode Class-D amplifier development board that operates at, but is not
limited to, 6.78 MHz (Lowest ISM band). The purpose of this development
board is to simplify the evaluation process of a high power ZVS Class-D
amplifier f or u se i n a pplications s uch a s A 4WP w ireless p ower u sing
eGaN® FETs by including all the critical components on a single board
that can be easily connected into an existing system. To support the
increased power capability, two mounted heat sinks are included.
The amplifier board features the EPC2007C and the EPC8010, which are
100 V rated enhancement-mode gallium nitride FETs (eGaN® FET). The
EPC2007C is used in the Class-D amplifier while the EPC8010 is used as a
synchronous bootstrap FET. The amplifier can be set to operate in either
differential m ode o r s ingle e nded m ode a nd i ncludes t he g ate d rivers
and 6.78 MHz oscillator.
For more information on the EPC2007C or EPC8010 eGaN FETs please
refer to the datasheet available from EPC at www.epc-co.com. The
datasheet should be read in conjunction with this quick start guide.
Table 1: Performance Summary (TA = 25°C) EPC9065
Symbol
Parameter
Min
Max
Units
VDD
Logic Input Voltage Range
Conditions
7.5
12
V
VAMP
Amp Input Voltage Range
0
80
V
VOUTA
Switch Node Output Voltage
80
V
VOUTB
Switch Node Output Voltage
80
V
IOUT
1.8*
ARMS
-0.3
3.5
0.8
5
V
V
VOsc_Disable
Switch Node Output Current
(each)
External Oscillator Input
Threshold
Oscillator Disable Voltage
Range
-0.3
5
V
IOsc_Disable
Oscillator Disable Current
-25
25
mA
Vextosc
Input ‘Low’
Input ‘High’
Open drain/
collector
Open drain/
collector
* Maximum current depends on die temperature – actual maximum current will be subject to switching
frequency, bus voltage and thermals.
DETAILED DESCRIPTION
The EPC9065 consists of a differential mode ZVS Class-D amplifier, a
6.78 MHz oscillator, and a separate heat sink for each Class-D
section. The power schematic of the EPC9065 is shown in figure 1.
For operating frequencies other than 6.78 MHz, the oscillator can be
disabled by placing a jumper into J60 or can be externally shutdown
using an externally controlled open collector / drain transistor on the
terminals of J60 (note which is the ground connection). The oscillator
disable switch needs to be capable of sinking at least 25 mA. The
external oscillator can then be connected to J71.
ZVS Timing Adjustment
+
L ZVS12
Q1
L ZVS1
1. With power off, connect the logic input supply (7.5 - 12 V) to VDD connector
(J90). Note the polarity of the supply connector.
2. Connect a LOW capacitance oscilloscope probe to the probe-hole of
the half-bridge to be set and lean it against the ground post as shown in
figure 3.
3. Turn on the logic supply – make sure the supply is set to approximately
7.5 - 12 V.
Q 11
L ZVS2
Q2
Q 12
C ZVS1
Setting the correct time to establish ZVS transitions is critical to achieving
high efficiency with the EPC9065 amplifier. This can be done by selecting
the values for R71, R72, R73, and R74 respectively. This procedure is best
performed using a potentiometer installed at the appropriate locations
(P71, P72, P73, and P74) that is used to determine the fixed resistor values.
The timing MUST initially be set without a load connected to the amplifier.
The timing diagrams are given in figure 4 and should be referenced when
following this procedure. Only perform these steps if changes have been
made to the board as it is shipped preset. The steps are:
PAGE 2 |
Coil connection
VIN
C ZVS2
Figure 1: Power schematic of the EPC9065 differential mode ZVS amplifier
4. Turn on the main supply voltage to 5 V to ensure that the switch node
waveform looks similar to figure 4. If not, adjust the potentiometers.
After verification, the main supply voltage can be set to the required
predominant operating value (such as 24 V but NEVER exceed the
absolute maximum voltage of 80 V).
5. While observing the oscilloscope, adjust the applicable potentiometers
to achieve the green waveform of figure 4.
6. Repeat for the other half-bridge.
7. Replace the potentiometers with fixed value resistors if required.
| EPC – EFFICIENT POWER CONVERSION CORPORATION | WWW.EPC-CO.COM | COPYRIGHT 2016
QUICK START GUIDE
EPC9065
Determining component values for LZVS
The ZVS tank circuit is not operated at resonance, and only provides the
necessary negative device current for self-commutation of the output
voltage at turn off. The capacitors CZVS1 and CZVS2 are chosen to have a very
small ripple voltage component and are typically around 1 µF. The amplifier
supply voltage, switch-node transition time will determine the value of
inductance for LZVSx which needs to be sufficient to maintain ZVS operation
over the DC device load resistance range and coupling between the device
and source coil range and can be calculated using the following equation:
LZVS =
∆tvt
(1)
8 ∙ fsw ∙ (2 ∙ COSSQ + Cwell)
Where:
ƒSW
= Operating Frequency [Hz]
COSSQ
= Charge Equivalent Device Output Capacitance [F]
Cwell
= Gate Driver Well Capacitance [F]. For the LM5113, use 20 pF.
The amplifier supply voltage VAMP is absent from the equation as
it is accounted for by the voltage transition time. The per device charge
equivalent capacitance can be determined using the following equation:
NOTE.
1 ∙ VAMP C
OSS (v) ∙ dv
∫
VAMP 0
3. With power off, connect the logic input power supply bus to +VDD
(J90). Note the polarity of the supply connector. This is used to power
the gate drivers and logic circuits.
4. Make sure all instrumentation is connected to the system.
6. Turn on the main supply voltage, starting at 0 V and increasing slowly
to the required value (it is recommended to start at 5 V for dead time
tuning purposes and do not exceed the absolute maximum voltage
of 80 V).
= Voltage Transition Time [s]
COSSQ =
2. With power off, connect the main input power supply bus to the
bottom pin of J50 and the ground to the ground connection of J50
as shown in figure 2.
5. Turn on the logic supply – make sure the supply is between 7.5 - 12 V.
Δtvt
1. Make sure the entire system, including the heat sink assembly, is fully
assembled prior to making electrical connections. This includes any
load to be connected.
(2)
To add additional immunity margin for shifts in load impedance, the
value of LZVS can be decreased to increase the current at turn off of the
devices (which will increase device losses). Typical voltage transition
times range from 2 ns through 12 ns. For the differential case the voltage
and charge (COSSQ) are doubled when calculating the ZVS inductance.
7. Once operation has been confirmed, adjust the main supply
voltage within the operating range and observe the output voltage,
efficiency and other parameters on both the amplifier and device
boards.
8. For shutdown, please follow steps in the reverse order. Start by
reducing the main supply voltage to 0 V followed by steps 6 through 2.
When measuring the high frequency content switch-node
(Source Coil Voltage), care must be taken to avoid long ground leads. An
oscilloscope probe connection (preferred method) has been built into the
board to simplify the measurement of the Source Coil Voltage (shown in
figure 3).
NOTE.
QUICK START PROCEDURE
The EPC9065 amplifier board is easy to set up and evaluate the
performance of the eGaN FET in a wireless power transfer application.
Please note that main power is connected directly to the amplifier.
Hence, there is no thermal or over-current protection to ensure the
correct operating conditions for the eGaN FETs. If the main power is
sourced from a benchtop DC power supply, it is highly advised to set a
reasonable current limit of 500 – 800 mA during initial evaluation.
EPC9065 amplifier board with heat sink photo
EPC – EFFICIENT POWER CONVERSION CORPORATION | WWW.EPC-CO.COM | COPYRIGHT 2016 |
|PAGE 3
EPC9065
Gate drive and
control supply
(note polarity)
0 - 80 V DC
+
+
7.5 - 12 V DC
VIN supply
(note polarity)
Amplifier
timing setting
(not installed)
External
oscillator
input
(optional)
Switch-node main
oscilloscope probe
Disable pre-regulator
jumper
Ground post
Amplifier board – Front-side
Figure 2: Proper connection and measurement setup for the amplifier board
Do not use probe
ground lead
Ground probe
against post
Place probe tip
in large via
Minimize loop
Figure 3: Proper measurement of the switch nodes using the hole and ground post
PAGE 4 |
| EPC – EFFICIENT POWER CONVERSION CORPORATION | WWW.EPC-CO.COM | COPYRIGHT 2016
QUICK START GUIDE
EPC9065
Q1 turn-off
Q2 turn-off
VAMP
VAMP
Q2 turn-on
0 Partial
Shootthrough
Q1 turn-on
0 Partial
time
ZVS
Shootthrough
ZVS
time
ZVS
ZVS + Diode
Conduction
ZVS
ZVS + Diode
Conduction
Figure 4: ZVS timing diagrams
THERMAL CONSIDERATIONS
The EPC9065 development board showcases the EPC2007C and EPC8010
eGaN FETs in a ZVS Class-D amplifier application. Although the electrical
performance surpasses that of traditional silicon devices, their relatively
smaller size does magnify the thermal management requirements. The
operator must observe the temperature of the gate driver and eGaN
FETs to ensure that both are operating within the thermal limits as per
the datasheets.
2–56 x 1/2 inch
nylon screw
Heat sink shim
Heat sink
(15 mm x 15 mm x 14.5 mm)
A heat sink kit is mounted on each half bridge of the EPC9065 board.
Figure 5 shows the assembly order for the heat sink kit.
Thermal interface material
for device 15 mm x 15 mm.
NOTE. The EPC9065 development board has no current protection on board and care
must be exercised not to over-current or over-temperature the devices. Excessively wide
coil coupling and load range variations can lead to increased losses in the devices.
Precautions
The EPC9065 development board has no controller or enhanced
protection systems and therefore should be operated with caution.
Some specific precautions are:
adhesive on both sides
of thermal pad
Cross-section
plane
OPTIONAL interface frame
heat sink rests on frame
(thickness = die thickness)
Mounting holes
center line
1. It is highly advised to set a reasonable current limit of 500 - 800 mA
during initial evaluation.
2. Ensure that the gap pad included in the heat sink assembly is firmly
compressed on the eGaN FETs prior to full power operation. Be careful
not to damage the die by over-tightening of the bolts.
EPC die
3. Please contact EPC at info@epc-co.com should there be questions
regarding specific load range impedance requirements.
2–56 nylon
hex nut
Figure 5: Heat sink kit assembly
EPC – EFFICIENT POWER CONVERSION CORPORATION | WWW.EPC-CO.COM | COPYRIGHT 2016 |
|PAGE 5
QUICK START GUIDE
EPC9065
Table 2: Bill of Materials - Amplifier Board
Item
Qty
Reference
Part Description
1
2
C1_1, C1_2
Capacitor, Ceramic, 4.7 µF, 10 V, ±20%, X5R
Samsung, CL05A475MP5NRNC
Manufacturer, Part Number
2
4
C5, C6, C15, C16
Capacitor, Ceramic, 2.2 µF 100 V, ±10%, X7R
Taiyo Yuden, HMK325B7225KN-T
3
2
Czvs1, Czvs2
Capacitor, Ceramic, 1.0 µF, 50 V, ±10%, X7R
Taiyo Yuden, C2012X7R1H105K125AB
4
3
C90, C91, C92
Capacitor, Ceramic, 1.0 µF, 25 V, ±10%, X7R
TDK, C1608X7R1E105K
5
11
C71, C72, C73, C74, C2_1, C2_2,
C4_1, C4_2, C5_1, C5_2, C60
Capacitor, Ceramic, 100 nF, 25 V, ±10%, X5R
TDK, C1005X5R1E104K050BC
6
8
C1, C2, C3, C4, C11, C12, C13, C14 Capacitor, Ceramic, 10 nF, 100 V, ±10%, X7S
TDK, C1005X7S2A103K050BB
7
2
C3_1, C3_2
Capacitor, Ceramic, 22 nF, 25 V, ±10%, X7R
TDK, C1005X7R1E223K050BB
8
4
C42, C43, C46, C47
Capacitor, Ceramic, 22 pF, 50 V, ±5%, NPO
TDK, C1005C0G1H220J050BA
9
1
R60
Resistor, 47 KΩ, ±5%, 1/10 W
Stackpole, RMCF0603JT47K0
10
1
R75
Resistor, 10 KΩ, ±5%, 1/10 W
Stackpole, RMCF0603FT10K0
11
2
R3_1, R3_2
Resistor, 2.74 KΩ, ±1%, 1/16 W
Panasonic, ERJ-2RKF2741X
12
2
R71, R74
Resistor, 470 Ω, ±1%, 1/16 W
Stackpole, RMCF0603FT470R
13
2
R72, R73
Resistor, 390 Ω, ±1%, 1/16 W
Stackpole, RMCF0603FT390R
14
2
R2_1, R2_2
Resistor, 20 Ω, ±5%, 1/16 W
Stackpole, RMCF0402FT20R0
15
2
R4_1, R4_2
Resistor, 6.8 Ω, ±5%, 1/10 W
Panasonic, ERJ-2GEJ6R8X
16
4
R1, R2, R11, R12
Resistor, 2.2 Ω, ±5%, 1/16 W
Yageo, RC0402JR-072R2L
17
2
R76, R77
Resistor, 0 Ω, 1/16 W, Jumper
Yageo, RC0402JR-070RL
Coilcraft, 2929SQ-391JEB
18
2
Lzvs1b, Lzvs2b
Inductor, 390 nH, ±5%, ±2%, Q=180 IRMS=4.4 A, 14.5 mΩ,
Resonance=590 MHz
19
8
D2_1, D2_2, D3_1, D3_2, D71,
D72, D73, D74
Diode, Schottky Diode, 30 V, VF=370 mV at 1 mA, 30 mA
Diodes Inc, SDM03U40-7
20
2
D4_1, D4_2
Diode, Zener, 5.1 V, 150 mW ±5%
Bourns Inc., BZT52C5V1T-7
21
2
D1_1, D1_2
Diode, Schottky, 40 V, 300 mA, VF=900 mV at 100 mA
ST Microelectronics, BAT54KFILM
22
4
Q1, Q2, Q11, Q12
eGaN® FET, 100 V, 6 A, RDS(on)=30 mΩ at 6 A, 5 V
EPC, EPC2007C
23
2
Q4_1, Q4_2
eGaN® FET, 100 V, 3.4 A, RDS(on)=160 mΩ at 500 mA
EPC, EPC8010
24
1
U90
IC’s, 5 V LDO, 250 mA, up to 16 VIN, Vdropout=0.33 V at 250 mA
Microchip, MCP1703T-5002E/MC
25
2
U1_1, U1_2
IC’s, Gate Driver, 5.2 VDC, 1.2 A, 4.5 V to 5.5 V
Texas Instruments, LM5113TME/NOPB
26
2
U72, U74
IC’s, Logic 2 NAND Gate, 1.65 V to 5.5 V, ± 24 mA
Fairchild, NC7SZ00L6X
27
2
U71, U73
IC’s, 2 Input NAND Gate, Tiny Logic, 1.65 V to 5.5 V, ± 32 mA
Fairchild, NC7SZ08L6X
Daishinku, DSO221SHF 6.780
28
1
U60
IC’s, Programmable Oscilator 1.5 to 60 MHz, VIN=1.8 V/2.5 V/2.8 V/3.0
V/3.3 V/5.0 V
29
2
TP1, TP2
Test Point, Test Point Subminiature
Keystone, 5015
30
3
J60, J71, J90
Header, Male Vertical, 36 Pin. 230" Contact Height, .1" Center Pitch
FCI, 68001-236HLF
31
1
J1
Connector, RP-SMA Plug, 50 Ω
Linx, CONREVSMA013.062
32
1
J50
Connector, Header 2 Pin .156 Pitch Vertical Gold
Molex Inc, 26614020
33
1
PCB1
PCB, EPC9065 REV 1
CCI, EPC9065 REV 1
34
1
C75
Capacitor, DNP, 100 pF, 25 V
Generic
35
4
P71, P72, P73, P74
Potentiometer, DNP, Multi Turn Potentiometer, 1 kΩ, ±10%, 1/4 W,
12 Turn Top Adjustment Small
Murata, PV37Y102C01B00
36
2
Lzvs1a, Lzvs2a
Inductor, DNP, 270 nH, ±5%, Q= 150, DCR= 12.5, F=50 MHz
CoilCraft, 2222SQ-271JEB
37
1
C44
IC’s, DNP, Programmable Oscillator 3.3 V, OE, Demo is
pre-programmed to 6.78 MHz
EPSON, SG-8002CE-PHB, or KDS Daishinku America,
DSO221SHF 6.780/1XSF006780EH
38
2
GP1, GP2
Header, DNP .1" Male Vert.
Tyco, 4-103185-0-01
EPC would like to acknowledge Coilcraft (www.coilcraft.com) and KDS Daishinku America (www.kdsamerica.com) for their support of this project.
EPC – EFFICIENT POWER CONVERSION CORPORATION | WWW.EPC-CO.COM | COPYRIGHT 2016 |
|PAGE 6
EPC – EFFICIENT POWER CONVERSION CORPORATION | WWW.EPC-CO.COM | COPYRIGHT 2016 |
L in
Hin
GND
GLH
GLL
L in
Gate Driver
GUR
GUH
GUL
C3
22 nF, 25 V
R2
20 Ω
GL H
GL L
GUR
GUH
GUL
5 VHS
4.7 V
GL H
D2
SDM03U40
R3
2.7 K
Gbtst
1
2
C4
100 nF, 25 V
GUR
D4
CD0603-Z5V1
5 VHS
C1
4.7 μF , 10 V
D1
B AT54K FIL M
5V
Synchronous Bootstrap Power Supply
6.8 Ω
R4
Figure 6: EPC9065 - Gate Driver Schematic
5 VHS
Hin
U1
L M5113TM
C5
100 nF, 25 V
4.7 V
D3
SDM03U40
C2
100 nF, 25 V
5V
1
2
5V
1
2
Q4
EPC8010
QUICK START GUIDE
EPC9065
|PAGE 7
Osc
.1" Male Ve rt.
1
2
J90
V7 in
Logic Supply
7.5 VDC - 12 VDC
C75
DNP 100 pF, 25 V
OSC
R75
10 K
Oscillator Output
.1" Male Vert.
1
2
1
2
VDD
OSC
OSC
OSC
OSC
B
B
A
C73
100 nF, 25 V
Y
U74
NC7SZ00L6X
U73
NC7SZ08L6X
U72
NC7SZ00L6X
IN
OUT
Logic Supply Regulator
C90
1 μF, 25 V
5V
5V
5V
Y
U90
5.0 V 250 mA DF N
C74
100 nF, 25 V
5V
5V
B
A
C72
100 nF, 25 V
5V
A
C71
100 nF, 25 V
5V
B
A
U71
NC7SZ08L6X
470 Ω
R7 1
2
390 Ω
R7 2
2
390 Ω
R7 3
2
470 Ω
R7 4
2
C91
1 μF, 25 V
D74
40 V, 30 mA
SDM03U40
DNP 1K
P74
Deadtime Left
1
D73
40 V, 30 mA
SDM03U40
DNP 1K
P73
Deadtime Right
1
D72
40 V, 30 mA
SDM03U40
DNP 1K
P72
Deadtime Left
1
D71
40 V, 30 mA
SDM03U40
DNP 1K
P71
Deadtime Right
1
C92
1 μF, 25 V
5V
H_Sig2
L _Sig2
L _Sig1
H_Sig1
H_Sig2
2
L _Sig1
1
GND
GL H
GL L
5V
GUR
GND
VCC
5V
OUT
3
Osc
C60
100 nF, 25 V
5V
U60
Pgm Osc.
Gate Driver
2
HighEffGateDrvr_r1_0.SchDoc
L in
Hi n
GUH
GUL
5 VHS
Gate Driver
Oscillator
OE
GND
GL H
GL L
5V
GUR
1
HighEffGateDrvr_r1_0.SchDoc
L in
Hi n
GUH
GUL
5 VHS
GL H2
GL L2
5V
OutB
GRH2
GRL2
5 VHS2
GL H1
GL L1
5V
OutA
GRH1
GRL 1
5 VHS1
Figure 7: EPC9065 – ZVS Class D Schematic
Oscillator Disable
2
R6 0
47 k
5V
C47
22 pF, 50 V
R7 7
0Ω
C43
22 pF, 50 V
L _Sig2 1
.1" Male Vert.
1
2
J60
C46
22 pF, 50 V
1
R7 6
0Ω
C42
22 pF, 50 V
H_Sig1
1
2
J71
G ND
4
2
R2
2Ω2
1
TP2
2 GRL 1
Q1
EPC2007C
2 GL L1
Q2
EPC2007C
Main Amplifier
R1
2Ω2
2 GRL2
Q11
EPC2007C
2
GLL2
Q12
EPC2007C
1
GP2
EMPTY
R12
2Ω2
Secondary Amplifier
R11
2Ω2
Ground Post
.1" Male Vert.
GL H2 1
GRH2 1
Ground Post
.1" Male Vert.
1
GP1
EMPTY
SMD probe loop
GL H1 1
GRH1 1
Vamp
SMD probe loop
1
TP1
OutB
Vamp
OutA
Vamp
Vamp
Czvs2
1 μF, 50 V
PH1
ProbeHole
Main Supply
0 V ~ 80 V 4 A max
1
2
J50
.156" Male Vert.
L zvs2b
390 nH
L zvs1b
390 nH
1
PAGE 8 |
PH2
ProbeHole
1
5V
Vamp
C4
10 nF, 100 V
Vamp
C3
10 nF, 100 V
C6
2.2 μF, 100 V
Vamp
C5
2.2 μF, 100 V
Vamp
HS 2
ZVS
Tank
Circuit
J1
SM A Board Edge
Vamp
C14
10nF, 100 V
Vamp
C13
10 nF, 100 V
C12
10 nF, 100 V
C11
10 nF, 100 V
C16
2.2 μF, 100 V
Vamp
C15
2.2 μF, 100 V
Vamp
HS- 15 mm x 15 mm WMount
Vamp
Vamp
L zvs2a
DNP 270 nH
Czvs1
1 μF, 50 V
L zvs1a
DNP 270 nH
C2
10 nF, 100 V
C1
10 nF, 100 V
HS 1
HS- 15 mm x 15 mm WMount
Vamp
Vamp
EPC9065
| EPC – EFFICIENT POWER CONVERSION CORPORATION | WWW.EPC-CO.COM | COPYRIGHT 2016
For More Information:
Please contact info@epc-co.com
or your local sales representative
Visit our website:
www.epc-co.com
Sign-up to receive
EPC updates at
bit.ly/EPCupdates
or text “EPC” to 22828
EPC Products are distributed through Digi-Key.
www.digikey.com
Demonstration Board Notification
The EPC9065 board is intended for product evaluation purposes only and is not intended for commercial use. As an evaluation tool, it is not designed for compliance with the European
Union directive on electromagnetic compatibility or any other such directives or regulations. As board builds are at times subject to product availability, it is possible that boards may contain
components or assembly materials that are not RoHS compliant. Efficient Power Conversion Corporation (EPC) makes no guarantee that the purchased board is 100% RoHS compliant. No
Licenses are implied or granted under any patent right or other intellectual property whatsoever. EPC assumes no liability for applications assistance, customer product design, software
performance, or infringement of patents or any other intellectual property rights of any kind.
EPC reserves the right at any time, without notice, to change said circuitry and specifications.
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