EPC9509

Demonstration System EPC9509 Quick Start Guide EPC2108 and EPC2036 6.78 MHz, ZVS Class-D Wireless Power AmplifierQUICK START GUIDE Demonstration System EPC9509 DESCRIPTION Table 1: Performance Summary (T = 25C) EPC9509 A The EPC9509 is a high efficiency, Zero Voltage Switching (ZVS), class-D Symbol Parameter Conditions Min Max Units wireless power amplifier demonstration board that operates at 6.78 MHz Also used in (Lowest ISM band). The purpose of this demonstration system is to sim- Bus Input Voltage Range V bypass mode 17 24 V IN Pre-Regulator Mode plify the evaluation process of wireless power amplifier technology using for logic supply Amp Input Voltage Range eGaN FETs by including all the critical components on a single board V 0 52 V IN Bypass Mode that can be easily connected into an existing system. Switch-Node Output V 52 V OUT Voltage The amplifier board features the enhancement-mode, half-bridge field Switch-Node Output I 1* A effect transistor (FET), the 60 V rated EPC2108 eGaN FET with integrated OUT Current (each) synchronous bootstrap FET. The amplifier can be set to operate in either External Oscillator Input V Input Low -0.3 0.8 V extosc Threshold differential mode or single-ended mode and includes the gate driver/s, Input High 2.4 5 V oscillator, and feedback controller for the pre-regulator that ensures Pre-Regulator Disable operation for wireless power control based on the A4WP standard. This V Floating -0.3 5.5 V Pre Disable Voltage Range allows for testing compliant to the A4WP class 3 standard over a load Pre-Regulator Disable I Floating -10 10 mA Pre Disable Current range as high as 50j . The pre-regulator features the 100 V rated 65 m Oscillator Disable Open Drain/ EPC2036 as the main switching device for a SEPIC converter. V -0.3 5 V Osc Disable Voltage Range Collector Oscillator Disable Open Drain/ For more information on the EPC2108 eGaN FETs please refer to the data- I -25 25 mA Osc Disable Current Collector sheet available from EPC at www.epc-co.com. The datasheet should be Differential or Single-Select Open Drain/ V -0.3 5.5 V sgnDiff read in conjunction with this quick start guide. Voltage Collector Differential or Single-Select Open Drain/ I -1 1 mA sgnDiff Current Collector DETAILED DESCRIPTION * Maximum current depends on die temperature actual maximum current will be subject to switching frequency, bus voltage and thermals. The Amplifier Board (EPC9509) Figure 1 shows the system block diagram of the EPC9509 ZVS class-D amplifier with pre-regulator and figure 2 shows the details of the ZVS class-D amplifier section. The pre-regulator is used to control the ZVS class-D wireless power amplifier based on three feedback parameters 1) the magnitude of the coil current indicated by the green LED, 2) the DC power drawn by the amplifier indicated by the yellow LED and 3) a maximum supply voltage to the amplifier indicated by the red LED. Only one parameter at any time is used to control the pre-regulator with the highest priority being the maximum voltage supplied to the amplifier followed by the power delivered to the amplifier and lastly the magnitude of the coil current. The maximum amplifier supply voltage is pre-set to 52 V and the maximum power drawn by the amplifier is pre-set to 16 W. The coil current magnitude is pre-set to 800 mARMS but can be made adjustable using P25. The pre-regulator comprises a SEPIC converter that can operate at full power from 17 V through 24 V. The pre-regulator can be bypassed by connecting the positive supply EPC9509 amplifier board photo directly to the ZVS class-D amplifier supply after removing jumper JP1 at location JP1 and connecting the main positive supply to the bottom pin. JP1 can also be removed and replaced with a DC ammeter to directly The amplifier comes with its own low supply current oscillator that is measure the current drawn by the amplifier. When doing this observe pre-programmed to 6.78 MHz 678 Hz. It can be disabled by placing a low impedance connection to ensure continued stable operation of a jumper into JP70 or can be externally shutdown using an externally the controller. Together with the Kelvin voltage probes (TP1 and TP2) controlled open collector / drain transistor on the terminals of JP70 (note connected to the amplifier supply, an accurate measurement of the which is the ground connection). The switch needs to be capable of power drawn by the amplifier can be made. The EPC9509 is also provided sinking at least 25 mA. An external oscillator can be used instead of the internal with a miniature high efficiency switch-mode 5 V supply to power the logic oscillator when connected to J70 (note which is the ground connection) circuits on board such as the gate drivers and oscillator. and the jumper (JP71) is removed. 2 EPC EFFICIENT POWER CONVERSION CORPORATION WWW.EPC-CO.COM COPYRIGHT 2017