EPC EPC9112 Посібник із швидкого старту - Сторінка 4

Переглянути онлайн або завантажити pdf Посібник із швидкого старту для Материнська плата EPC EPC9112. EPC EPC9112 13 сторінок. 6.78 mhz, zvs class-d wireless power system using epc2007c / epc2038

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QUICK START GUIDE

Where:

Δt

= Voltage transition time [s]

= Operating frequency [Hz]

= Charge equivalent device output capacitance [F].

OSSQ

Note that the amplifier supply voltage V

equation as it is accounted for by the voltage transition time.

The charge equivalent capacitance can be determined using the

following equation:

∫

∙

OSSQ

AMP

To add additional immunity margin for shifts in coil impedance, the

value of L

can be decreased to increase the current at turn off

ZVS

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 (C

) are doubled.

OSSQ

QUICK START PROCEDURE

The EPC9112 demonstration system is easy to set up and evaluate the

performance of the eGaN FET in a wireless power transfer application.

Refer to Figure 1 to assemble the system and Figures 5 and 7 for proper

connection and measurement setup before following the testing

procedures.

The EPC9507 can be operated using any one of two alternative methods:

a. Using the pre-regulator

b. Bypassing the pre-regulator

a. Operation using the pre-regulator

The pre-regulator is used to supply power to the amplifier in this mode

and will limit the DC current to the amplifier based on the setting. The

pre-regulator also monitors the temperature of the amplifier and will limit

the current in the event the temperature exceeds 85°C.

1. Make sure the entire system is fully assembled prior to making electrical

connections and make sure jumper (JP60 is set to pre-regulator

– right 2 pins).

2. With power off, connect the main input power supply bus to +V

(J50). Note the polarity of the supply connector.

3. With power off, connect the control input power supply bus to +V

(J90). Note the polarity of the supply connector.

4. Select and connect an applicable load resistance to the device board.

5. Make sure all instrumentation is connected to the system.

6. Turn on the control supply – make sure the supply is between 7 V and

12 V (7.5 V is recommended).

7. Turn on the main supply voltage to the required value (it is

recommended to start at 8 V and do not exceed the absolute

maximum voltage of 32 V).

4 |

is absent from the

AMP

V AMP

(2)

(v) ∙ dv

OSS

| EPC – EFFICIENT POWER CONVERSION CORPORATION |

The Source Coil

Figure 3 shows the schematic for the source coil which is Class 3 A4WP

compliant. The matching network includes both series and shunt tuning.

The matching network series tuning is differential to allow balanced

connection and voltage reduction for the capacitors.

The Device Board

Figure 4 shows the basic schematic for the device coil which is Category 3

A4WP compliant. The matching network includes both series and shunt

tuning. The matching network series tuning is differential to allow balanced

connection and voltage reduction for the capacitors.

The device board comes equipped with a kelvin connected output DC

voltage measurement terminal and a built in shunt to measure the output

DC current.

Two LEDs have been provided to indicate that the board is receiving power

with an output voltage greater than 4 V (green LED) and that the board

output voltage limit has been reached (greater than 36 V using the red LED).

8. 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.

9. 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.

b. Operation bypassing the pre-regulator

In this mode, the pre-regulator is bypassed and the main power is

connected directly to the amplifier. This allows the amplifier to be

operated using an external regulator or to test at higher voltages.

In this mode there is no current or thermal protection for the eGaN FETs.

1. Make sure the entire system is fully assembled prior to making electri-

cal connections and remove the jumper JP60 and insert it into J51 to

place the EPC9507 amplifier in bypass mode. Never connect the main

power positive (+) to J50 when operating in bypass mode.

2. With power off, connect the main input power supply ground to the

ground terminal of J50 (-) and the positive (+) to the center pin of JP60.

3. With power off, connect the control input power supply bus to +V

(J90). Note the polarity of the supply connector.

4. Select and connect an applicable load resistance to the device board.

5. Make sure all instrumentation is connected to the system.

6. Turn on the control supply – make sure the supply is between 7 V and

12 V range (7.5 V is recommended).

7. Turn on the main supply voltage to the required value (it is recom-

mended to start at 2 V and do not exceed the absolute maximum

voltage of 80 V).

Demonstration System EPC9112