SN74S85是TI公司的一款数字比较器产品，SN74S85是4 位二进制或 BCD 幅度比较器，本页介绍了SN74S85的产品说明、应用、特性等，并给出了与SN74S85相关的TI元器件型号供参考。
SN74S85 - 4 位二进制或 BCD 幅度比较器 - 数字比较器 - 特殊逻辑 - TI公司（Texas Instruments，德州仪器）
These four-bit magnitude comparators perform comparison of straight binary and straight BCD (8-4-2-1) codes. Three fully decoded decisions about two 4-bit words (A, B) are made and are externally available at three outputs. These devices are fully expandable to any number of bits without external gates. Words of greater length may be compared by connecting comparators in cascade. The A > B, A < B, and A = B outputs of a stage handling less-significant bits are connected to the corresponding A > B, A < B, and A = B inputs of the next stage handling more-significant bits. The stage handling the least-significant bits must have a high-level voltage applied to the A = B input. The cascading paths of the '85, 'LS85, and 'S85 are implemented with only a two-gate-level delay to reduce overall comparison times for long words. An alternate method of cascading which further reduces the comparison time is shown in the typical application data.
