... many thanks for the hints I received until now. Meanwhile I started on asking especially chip suppliers who have many die maps available. I just want to clarify that the one fact I definitely know is that it is NOT XR2206. I mailed my pictures to the EXAR technicians and they told me that it is definitely not XR2206. Before we opened the unlabeled IC, some facts (pin number, power supply pins, circuitry round the IC) made us hope it would be XR2206. Many thanx, regards Matthias Mansfeld ----------------------------------------------- Matthias Mansfeld Elektronik * Printed Circuit Board Design and Assembly Am Langhoelzl 11, D-85540 Haar, GERMANY Phone: +49-89-4620 0937, Fax: +49-89-4620 0938 E-Mail: [log in to unmask] Internet: http://www.mansfeld-elektronik.de ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################