Combined datasheet for the SMBTA42 and MMBTA42, surface-mount versions of the high-voltage A42 NPN transistor, in a 525 KB PDF. These SOT-23 parts are often found in display drivers, telephone lines and power supply start-up circuits where collector voltage is high. The sheet should list voltage and current ratings, hFE, marking code and package drawing. Technicians use the marking code to identify an unlabelled SMD transistor and confirm pin order before testing with a meter or replacing it with a suitable equivalent.
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