Microsemi1KWRFE類發(fā)生器方案

Microsemi公司的 1KW RF E類發(fā)生器采用DRF1200驅(qū)動器/MOSFET混合模塊。DRF1200可產(chǎn)生過1KW 的輸出功率，它包括了MOSFET 驅(qū)動器，大功率MOSFET和內(nèi)部旁路電容。而 E類放大器具有線性電路設(shè)計所不能達(dá)到的高效率，但是它的設(shè)計高度復(fù)雜。采用DRF1200/CLASS-E參考設(shè)計，工程師就會很快克服高壓E類放大器設(shè)計的難處。本文介紹了DRF1200的主要性能，簡化電路和測試電路以及DRF1200/CLASS-E參考板的主要性能，整體電路圖，PCB 布局和所用的元器件列表。

13.56 MHz, CLASS-E, 1KW RF Generator using a Microsemi DRF1200 Driver/MOSFET Hybrid

CLASS-E amplifiers offer a degree of efficiency unavailable with linear designs. The trade-off has been the high level of design complexity that engineers have either shied away from or spent months discovering the fundamentals of practical CLASS-E amplifier design. With the DRF1200/CLASS-E reference design kit an engineer can rapidly overcome the pitfalls of high voltage CLASS-E design. It demonstrates fundamental design techniques that can save months of countless design iterations.



This application note discusses the design procedures and test results for a 13.56MHz, 1KW, CLASS-E generator ideal for ISM applications. To achieve high efficiency and low cost, a Microsemi DRF1200 Driver/MOSFET was selected. The DRF1200 can generate over 1KW of output power and consists of a MOSFET driver, high power MOSFET and internal bypass capacitors in an air cavity flangeless package. The flangeless package was designed to optimize reliability, provide increased flexibility while still providing a low cost solution. A reference design board (DRF1200/CLASS-E) is available for purchase to facilitate the immediate evaluation of the principles of this application note.

To optimize efficiency performance, a CLASS-E RF generator was chosen. It is essential that care is taken to use adequate circuitry, clean PCB layout and good ground connections on the PCB to ensure proper output waveforms.

The DRF1200 hybrid includes a high power gate driver and the power MOSFET. The driver output can be confi gured as Inverting and Non-Inverting. It was designed to provide the system designer increased fl exibility and lowered cost over a non-integrated solution.

主要特性：
Switching Frequency: DC TO 30MHz
Low Pulse Width Distortion
Single Power Supply
1V CMOS Schmitt Trigger Input 1V Hysteresis
Inverting Non-Inverting Select
RoHS Compliant
Switching Speed 3-4ns
BVds = 1Kv
Ids = 13A avg.
Rds(on) ≤ 0.90 Ohm
PD = 624W

典型應(yīng)用：
Class C, D and E RF Generators
Switch Mode Power Amplifi ers
Pulse Generators
Ultrasound Transducer Drivers
Acoustic Optical Modulators



圖1. DRF1200 簡化電路圖



圖2.DRF1200 測試電路圖



圖3.整體電路圖



圖4.PCB 布局

下表為1KW RF E類發(fā)生器所用元器件