SA555DTIC OSC MONO TIMING 500KHZ 8SOIC|STMICROELECTRONICS|Lead free|RoHS Compliant NA555DR SA555DTIC OSC MONO TIMING 500KHZ 8SOIC|STMICROELECTRONICS (VA)|Lead free|RoHS Compliant NA555DR SA555DTIC OSC MONO TIMING 500KHZ 8SOIC|STMICROELECTRONICS (VA)|Lead free|RoHS Compliant NA555DR