常用74系列芯片特性分类及中文名称资料(国外英文资料).docVIP

常用74系列芯片特性分类及中文名称资料(国外英文资料) The 74 series of integrated circuits can be broadly divided into 6 major categories: 74 * * (standard type); 74LS * * (low power Schottky); 74S * * (Schottky); 74ALS x (advanced low power Schottky barrier); 74AS * * (advanced schottky barrier); 74F * x (high speed). In recent years, the 74 series of high-speed CMOS circuits have emerged. The series can be divided into 3 major categories: HC is the COMS operating level; HCT is the working level of TTL and can be used interchangeably with 74LS series; HCU is CMOS in the buffer circuit. The 9 74 series products have the same logic function and pin arrangement as long as the label is the same. Users should choose different types of 74 series products according to different conditions and requirements. For example, when the supply voltage of the circuit is 3V, 74HC series products should be selected. Series level typical transmission delay ns maximum drive current (-Ioh/Lol) mA AHC CMOS 8.5 -8/8 AHCT COMS/TTL 8.5 -8/8 HC COMS 25 -8/8 HCT COMS/TTL 25 -8/8 ACT COMS/TTL 10 -24/24 F TTL 6.5 -15/64 ALS TTL 10 -15/64 LS TTL 18 -15/24 LVC AC S LC Explain： 1) LS is low power Schottky, HC is high-speed COMS; LS is faster than HC; HCT input and output are compatible with LS; but power consumption is low; F is high-speed Schottky circuit; 2) LS is the TTL level, and the HC is the COMS level; 3) the LS input is open to high, and the HC input is not allowed to open. The HC generally requires a pull-down resistor to determine the level at which the input is not valid. The LS does not have this requirement; 4) LS output drop-down, strong pull up weak, HC pull down the same; 5) work voltage is different: LS can only use 5V, and HC is generally 2V to 6V; 6) the level is different: LS is the TTL level, its low level and high level are 0.8 and V2.4, and CMOS at the operating voltage is 5V, respectively 0.3V and 3.6V, so CMOS can drive TTL, but the reverse is not; 7) driving ability is different: LS general high