infineon公司的IGT40R070D1 E8220是400V Cool增强模式氮化镓高迁移率晶体管(GaN HEMT).该器件通过在体二极管的零反向恢复电荷和非常小的线性输入和输出电容,克服了技术阻挡层如线性和功率损耗.CoolGaN™由于具有低/线性Coss,零Qrr和常开开关,理想的D类音频放大器提供0%失真和100%效率.D类放大器线性和功率损耗是高度依赖于开关器件的开关特性. Infineon公司的CoolGaN™通过引入体二极管的零反向恢复电荷和非常小的线性输入和输出电容,打破了这种技术壁垒.此外,增强模式提供了快速开合和关断速度,以及在单个芯片或封装内更好的集成通路.这种特性使得CoolGaN™和IRS20957SPBF D类控制器配对时更简便,能是客户更快的设计和更早走向市场.本文介绍了IGT40R070D1 E8220主要特性,电感负载开关时间测试电路以及采用IRS20957SPBF + IGT40R070D1 E8220评估板EVAL_AUDAMP24主要特性,主板和子板电路图,材料清单和PCB设计图.
The CoolGaN™ 400V e-mode GaN HEMT is a derivative of the industry benchmark CoolGaN™ 600V technology. This enhancement-mode power transistor (IGT40R070D1 E8220) overcomes the technology barriers, such as linearity and power loss, by introducing zero reverse recovery charge in the body diode and very small, linear input and output capacitances. The IGT40R070D1 E8220 is optimized for class D audio amplifie r applications where it provides excellent audio experience.
400V CoolGaN™ enhancement-mode Power Transistor
The 400V CoolGaNTM family is the derivative of industry benchmark 600V CoolGaNTM technology, optimized for Class-D Audio amplifier applications.
CoolGaN™ enables smoother switching and more linear class D output stage by offering
low/linear Coss, zero Qrr, and normally-off switch. Ideal class D audio amplifiers offer zero percent distortion and 100 percent efficiency. What impairs the linearity and power loss is highly dependent on switching characteristics of the switching device. Infineons CoolGaN™ breaks through the technology barrier by introducing zero reverse recovery
charge in the body diode and very small, linear input and output capacitances.
In addition, the enhancement-mode concept offers fast turn-on and turn-off speed as well as a better path towards integration either on a chip or package level. This feature also simplifies pairing CoolGaN™ with the IRS20957SPBF class D controller and therefore
enables faster design-in and time-to-market for our customers.
CoolGaN™ for class D audio
CoolGaN™ 400 V is tailored for premium HiFi home audio, professional, and aftermarket
car audio systems where end users demand every detail of their high-resolution soundtracks. These have been conventionally addressed by bulky linear or tube amplifiers. With CoolGaN™ 400 V as class D output stage, audio designers are able to deliver the best listening experience to their prospective audio fans.
Infineons CoolGaN™ 400 V device, IGT40R070D1 E8220 in HSOF-8-3 (TO-leadless) package has been tested in class D audio amplifier applications on 200 W + 200 W dual channel system designs. Please refer to EVAL_AUDAMP24 for more details.
››Ultralow and linear Coss 400 V power device
››Enhancement-mode transistor –normally-off switch
››Capable of reverse conduction
››Low gate charge, low output charge
››Superior commutation ruggedness
››Qualified according to JEDEC standards (JESD47 and JESD22)
››Outstanding audio quality
››Clean switching performance
››Narrow dead time for better THD
››Improves efficiency due to best figure of merit (FOM) in the 400 V class
››Easy to use: compatible with the IRS20957SPBF class D controller
· Class-D Audio Amplifier
图1. IGT40R070D1 E8220电感负载开关时间测试电路
图2. IGT40R070D1 E8220反向通路特性图
IRS20957SPBF + IGT40R070D1 E8220评估板EVAL_AUDAMP24
The EVAL_AUDAMP24 GaN e-mode High Electron Mobility Transistor (HEMT) evaluation board is a two-channel, 225 W/ch (4 Ω at ±43 V) or 250 W/ch (8 Ω at ±63 V) half-bridge class D audio power amplifier for Hi-Fi audio systems. This evaluation board demonstrates how to use the CoolGaN™ gallium nitride transistor, IRS20957S controller IC, implement protection circuits, and design an optimum PCB layout using the IGT40R070D1 E8220, CoolGaN™ gallium nitride transistor. The reference design provides all the required housekeeping power supplies for ease of use. The two-channel design is scalable for power and the number of channels.
The EVAL_AUDAMP24 features a two-channels self-oscillating type PWM modulator for the lowest component count, highest performance and robust design. This topology represents an analog version of a second-order sigma-delta modulation, having a class D switching stage inside the loop. The benefit of the sigma-delta modulation, in comparison to the carrier-signal based modulation, is that all the error in the audible frequency range is shifted to the inaudible upper-frequency range by nature of its operation. Also, sigma-delta modulation enables the designer to apply sufficient error correction.
· Output power:
− 225 W x 2 channels (1 percent THD+N, 4 Ω at ±43 V)
− 250 W x 2 channels (1 percent THD+N, 8 Ω at ±63 V)
· Multiple protection features:
− Over-Current Protection (OCP), high-side and low-side CoolGaN™ transistors
− Over-Voltage Protection (OVP)
− Under-Voltage Protection (UVP), high-side and low-side CoolGaN™ transistors
− Over-Temperature Protection (OTP)
· PWM modulator:
− Self-oscillating half-bridge topology with optional clock synchronization
· Hi-Fi amplifiers
· AV receivers
· Home theater systems
· Powered speakers
· Musical instrument amplifiers
The EVAL_AUDAMP24 self-oscillating topology consists of the following essential functional blocks:
· Front-end integrator
· PWM comparator
· Level shifters
· Gate drivers and CoolGaN™ HEMTs
· Output LPF
图10. 评估板EVAL_AUDAMP24 PCB设计图:主板正面
图11. 评估板EVAL_AUDAMP24 PCB设计图:主板背面
图12. 评估板EVAL_AUDAMP24 PCB设计图:子板正面
图13. 评估板EVAL_AUDAMP24 PCB设计图:子板背面