MCP7940N-E/SN MCP7940N-E/SNVAO MCP7940N-I/MS MCP7940N-I/P MCP7940N-I/SN MCP7940N-I/SN 工控元件 MCP7940N-I/ST MCP7940NT-E/MS MCP7940NT-E/MSVAO MCP7940NT-E/SN