器件名称:
MC74AC157N
功能描述:
QUAD 2-INPUT MULTIPLEXER
文件大小:
165.68KB 共6页
简 介:
MC74AC157 MC74ACT157 Quad 2Input Multiplexer The MC74AC157/74ACT157 is a high-speed quad 2-input multiplexer. Four bits of data from two sources can be selected using the common Select and Enable inputs. The four outputs present the selected data in the true (noninverted) form. The MC74AC157/74ACT157 can also be used as a function generator. Outputs Source/Sink 24 mA ′ACT157 Has TTL Compatible Inputs QUAD 2-INPUT MULTIPLEXER VCC 16 E 15 I0c 14 I1c 13 Zc 12 I0d 11 I1d 10 Zd 9 N SUFFIX CASE 648-08 PLASTIC PIN NAMES I0a–I0d I1a–I1d E S Za–Zd Source 0 Data Inputs Source 1 Data Inputs Enable Input Select Input Outputs 1 S 2 I0a 3 I1a 4 Za 5 I0b 6 I1b 7 Zb 8 GND D SUFFIX CASE 751B-05 PLASTIC TRUTH TABLE Inputs E H L L L L S X H H L L I0 X X X L H I1 X L H X X Outputs Z L L H L H LOGIC SYMBOL E I0a I1a I0b I1b I0c I1c I0d I1d S Za Zb Zc Zd H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial FACT DATA 5-1 MC74AC157 MC74ACT157 FUNCTIONAL DESCRIPTION The MC74AC157/74ACT157 is a quad 2-input multiplexer. It selects four bits of data from two sources under the control of a common Select input (S). The Enable input (E) is active-LOW. When E is HIGH, all of the outputs (Z) are forced LOW regardless of all other inputs. The MC74AC157/ 74ACT157 is the logic implementation of a 4-pole, 2-position switch where the position of the switch is determined by the logic levels supplied to the Select input. The logic equations for the outputs are shown below: Za = E……
