© 1999 Scenix Semiconductor, Inc. All rights reserved. - 5 - www.scenix.com SX18AC  / SX20AC / SX28AC 2.3    Part Numbering   Table 2-1.  Ordering Information Device Pins I/O EE/Flash (Words) RAM (Bytes) SX18AC/SO 18 12 2K 136 SX18AC/DP 18 12 2K 136 SX20AC/SS 20 12 2K 136 SX28AC/SO 28 20 2K 136 SX28AC/DP 28 20 2K 136 SX28AC/SS 28 20 2K 136 Figure 2-1. Part Number Reference Guide SX18ACXX-LI/SO Package Type Extended Temperature Low Voltage Memory Size Feature Set Pin Count SceniX A = 512 word B = 1k word C = 2k word D = 4k word Speed Blank = 50 MHz 75 = 75 MHz 100 = 100 MHz DP = DIP SO = SOP SS = SSOP TQ = Thin PQFP PQ = PQFP Blank = 2.5V - 5.5V L = Low Voltage (TBD) Blank = 0°C to +70°C I = -40°C to +85°C