LM139DT by STMicroelectronics Design and production,in Hong Kong QX Electronics Limited Spot sales,And can pass Hong Kong QX Electronics Limited Purchasing。LM139DT Price reference $ 0.249400。LM139DT - 。You can download Chinese information、Pin map、DatasheetData sheet function specification,In the information LM139DT Detailed pin diagram and function application circuit diagram voltage and usage method and tutorial