EPC EPC9112 Skrócona instrukcja obsługi - Strona 5

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QUICK START GUIDE

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. See Pre-Cautions when operating in the bypass mode

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.

NOTE. 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 (J2 and J3 as shown in Figure 3).

SWITCHING BETWEEN SINGLE-ENDED

AND DIFFERENTIAL MODE OPERATION

The ZVS class-D amplifier can be operated in either single-ended or

differential mode operation by changing the jumper setting of J75.

When inserted the amplifier operates in the single-ended mode. Using

an external pull down with floating collector/ drain connection will have

the same effect. The external transistor must be capable of sinking 25 mA

and withstand at least 6 V.

THERMAL CONSIDERATIONS

The EPC9112 demonstration system showcases the EPC2007C and

EPC2038 eGaN FETs in a wireless energy transfer application. Although

the electrical performance surpasses that of traditional silicon devices,

Class 3

Coil

Figure 3: Diagram of the A4WP Class 3 Source Coil

EPC – EFFICIENT POWER CONVERSION CORPORATION |

Bypass Mode

Connection

Pre-

Regulator

J50

Pre-

Regulation

Connection

Figure 2: Diagram of EPC9507 Amplifier Board

Matching

Impedance

Network

Coil

Connection

Source Coil

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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.

NOTE. The EPC9112 demonstration system has limited current and thermal protection

only when operating off the Pre-Regulator. When bypassing the pre-regulator there is no

current or thermal protection on board and care must be exercised not to over-current or

over-temperature the devices. Wide coil coupling and load range variations can lead to

increased losses in the devices.

Pre-Cautions

The EPC9112 demonstration system has no controller or enhanced

protections systems and therefore should be operated with caution.

Some specific precautions are:

1. Never operate the Source Coil within 6 inches in any direction of any

solid metal objects as this will shift the tuning of the coil. Please con-

tact EPC should the tuning of the coil be required to change to suit

specific conditions so that it can be correctly adjusted for use with the

ZVS class-D amplifier.

2. There is no heat-sink on the devices and during experimental

evaluation it is possible present conditions to the amplifier that may

cause the devices to overheat. Always check operating conditions and

monitor the temperature of the EPC devices using an IR camera.

Pre-Regulator

Jumper

AMP

JP60

Coil

Connection

ZVS12

ZVS2

ZVS1

ZVS2

Matching

Impedance

Network

Cat. 3

Coil

Device Board

Figure 4: Basic Schematic of the A4WP Category 3 Device Board

Demonstration System EPC9112

Single

Ended

Operation

Jumper

Un-Regulated

DC output

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