MMBT3904 by STMicroelectronics Design and production,in Shenzhen Tuoyue Electronics Co., Ltd. Spot sales,And can pass Shenzhen Tuoyue Electronics Co., Ltd. Purchasing。MMBT3904 Price reference $ 0。MMBT3904 - 。You can download Chinese information、Pin map、DatasheetData sheet function specification,In the information MMBT3904 Detailed pin diagram and function application circuit diagram voltage and usage method and tutorial