MC74HCT138A屬于集成電路（IC）的信號開關多路復用器解碼器。由安森美半導體公司制造生產的MC74HCT138A信號開關，多路復用器，解碼器邏輯型信號開關、多路復用器和編碼器 IC 可用于對以數字格式表示數據的電信號進行路由和選擇。這些器件與設計用于模擬信號的類似產品有所不同，它們保留的信息表示為兩個電狀態(tài)之一，而不是兩個外部界限內的無窮變化量。

The MC74HCT138A is identical in pinout to the LS138. The HCT138A may be used as a level converter for interfacing TTL or

NMOS outputs to High Speed CMOS inputs. The HCT138A decodes a three?bit Address to one?of?eight active?lot outputs. This device features three Chip Select inputs, two active?low and one active?high to facilitate the demultiplexing, cascading, and chip?selecting functions. The demultiplexing function is accomplished by using the Address inputs to select the desired

device output; one of the Chip Selects is used as a data input while the other Chip Selects are held in their active states.

Features

? Output Drive Capability: 10 LSTTL Loads

? TTL/NMOS Compatible Input Levels

? Outputs Directly Interface to CMOS, NMOS, and TTL

? Operating Voltage Range: 4.5 to 5.5 V

? Low Input Current: 1.0 A

? In Compliance with the Requirements Defined by JEDEC Standard

No. 7A

? Chip Complexity: 122 FETs or 30.5 Equivalent Gates

? Pb?Free Packages are Available*