Other Parts Discussed in Thread: LMG1210
中文版本(Chinese version)：
我的目的是使用LMG1210驱动由GaN Systems的GS61008P组成的半桥电路。我按照LMG1210 EVM进行原理图和印制板设计。我期望LMG1210工作在IIM模式，所以我将DLH引脚连接到LMG1210内部LDO的5V输出端，同时将DHL引脚直接连接到GND。在测试中，我向LMG1210的HI引脚和LI引脚输入了互补的PWM信号，用示波器查看了LO、HO与HB的信号。结果显示，只有LO输出了LI相同的波形。另外，虽然自举电容的电压已经被抬升至5V，但HO仍然没有任何输出。请问是什么影响了HO引脚的输出？
非常感谢您的解答！末尾附有一些图片，它们能支持我的说明。(我重新焊接了多次，我可以确信不是焊接问题。)
English version:
I’m using LMG1210 to drive a half bridge circuit. The power switches used here is GS61008P. The manufacturer is GaN Systems. I designed my SCH and PCB according to LMG1210 EVM files. I want LMG1210 to work in the IIM mode, so I connected DLH pin to the VDD pin of the internal LDO, and the DHL pin to GND. In my experiment, I input a pair of complimentary PWM signals(there is 40ns deadtime between them) to the LI and HI pins. Then I checked signals of LO, HO, and HB pins using my oscilloscope. The result is that, the waveform at the LO pin is the same as LI. However, the waveform at the HO pin is keeping low. I checked the bootstrap capacitor. The voltage of CBST is well at 5V. What affects the output of the HO pin? Thank you very much for your answer! At the end are some pictures to support my explanation. (I re-soldered the board many times and I'm pretty sure it wasn't a soldering issue.)
图1 PCB layout of “LMG1210 EVM”
图2 PCB layout in my design
图3 My PCB Board
图4 OSC Screenshot1 (There is no HO waveform here, but I can tell you there’s no output at HO)
图5 My SCH
图6 My PCB-1
图7 My PCB-2
reference link: www.ti.com.cn/.../LMG1210EVM-012
