ꢀꢁ ꢂꢃ ꢄꢀ ꢅ ꢆ ꢇꢄ ꢈꢉ ꢀꢁꢂ ꢃꢄ ꢀ ꢅꢆ ꢊꢋ
ꢊ ꢉꢌ ꢍ ꢉꢊ ꢎ ꢉ ꢏꢄꢐꢄꢉꢀ ꢑꢒ ꢑꢓꢐꢌ ꢔꢀꢕ ꢖꢗ ꢒꢐ ꢘꢙ ꢒꢑ ꢚꢑ ꢔ ꢀ
ꢛ ꢘꢐ ꢜꢉ ꢝ ꢞꢀꢐꢄꢐ ꢑꢉ ꢌ ꢗꢐ ꢙꢗ ꢐꢀ
ꢟ
SDAS154A − D2822, DECEMBER 1983 − REVISED JANUARY 1990
• 4-Line to 1-Line Data Selectors/Multiplexers
That Can Select 1 of 16 Data Inputs Typical
Applications:
SN74AS850A, SN74AS851B . . . N PACKAGE
(TOP VIEW)
Boolean Function Generators
Parallel-to-Serial Converters
Data Source Selectors
V
D8
D9
D10
D11
D12
1
28
27
26
25
24
23
D7
D6
D5
D4
D3
D2
D1
D0
GY
G
CC
2
3
4
• Cascadable to n-Bits
5
• 3-State Bus Driver Outputs
6
• ’AS850A Offers Clocked Selects; ’AS851B
7
22 D13
21 D14
20 D15
Offers Enable-Controlled Selects
8
• Has a Master Output Control (G) for
Cascading and individual Output Controls
(GY, GW) for Each Output
9
10
11
12
13
14
19
Y
18 S0
17 S1
16 S2
15 S3
GW
†
• Package Option Includes 600-mil Standard
CLK/SC
Plastic DIPs
W
GND
• Dependable Texas Instruments Quality and
Reliability
†
CLK for ’AS850A or SC for ’AS851B
description
These four-line to one-line data selectors/multiplexers provide full binary decoding to select one-of-sixteen data
sources with complementary Y and W outputs. The ’AS850A has a clock-controlled select register allowing for
a symmetrical presentation of the select inputs to the decoder while the ’AS851B has an enable-controlled select
register allowing the user to select and hold one particular data line.
A buffered group of output controls (G, GY, GW) can be used to place the two outputs in either a normal logic
(high or low logic level) or a high-impedance state. In the high-impedance state, the outputs neither load nor
drive the bus lines significantly. The high-impedance third state and increased drive provide the capability to
drive the bus lines in a bus-organized system without the need for interface or pullup components.
The output controls do not affect the internal operations of the data selector/multiplexer. New data can be setup
while the outputs are in the high-impedance state.
The SN74AS850A and SN74AS851B are characterized for operation from 0°C to 70°C.
ꢙ
ꢙ
ꢔ
ꢌ
ꢯ
ꢏ
ꢪ
ꢗ
ꢓ
ꢨ
ꢐ
ꢩ
ꢘ
ꢣ
ꢌ
ꢡ
ꢁ
ꢢ
ꢏ
ꢄ
ꢐ
ꢄ
ꢠ
ꢡ
ꢫ
ꢢ
ꢣ
ꢩ
ꢤ
ꢥ
ꢦ
ꢦ
ꢧ
ꢧ
ꢠ
ꢠ
ꢣ
ꢣ
ꢡ
ꢡ
ꢠ
ꢨ
ꢨ
ꢬ
ꢩ
ꢪ
ꢤ
ꢤ
ꢫ
ꢫ
ꢡ
ꢧ
ꢦ
ꢥ
ꢨ
ꢨ
ꢣ
ꢢ
ꢬ
ꢐꢫ
ꢪ
ꢭ
ꢨ
ꢮ
ꢠ
ꢩ
ꢦ
ꢨ
ꢧ
ꢠ
ꢧ
ꢣ
ꢤ
ꢡ
ꢪ
ꢯ
ꢦ
ꢡ
ꢧ
ꢧ
ꢫ
ꢨ
ꢰ
Copyright 1990, Texas Instruments Incorporated
ꢤ
ꢣ
ꢩ
ꢧ
ꢣ
ꢤ
ꢥ
ꢧ
ꢣ
ꢨ
ꢬ
ꢠ
ꢢ
ꢠ
ꢩ
ꢫ
ꢤ
ꢧ
ꢱ
ꢧ
ꢫ
ꢤ
ꢣ
ꢢ
ꢲ
ꢦ
ꢘ
ꢡ
ꢥ
ꢫ
ꢨ
ꢧ
ꢦ
ꢡ
ꢯ
ꢦ
ꢤ
ꢯ
ꢳ
ꢦ
ꢧ ꢫ ꢨ ꢧꢠ ꢡꢵ ꢣꢢ ꢦ ꢮꢮ ꢬꢦ ꢤ ꢦ ꢥ ꢫ ꢧ ꢫ ꢤ ꢨ ꢰ
ꢤ
ꢤ
ꢦ
ꢡ
ꢧ
ꢴ
ꢰ
ꢙ
ꢤ
ꢣ
ꢯ
ꢪ
ꢩ
ꢧ
ꢠ
ꢣ
ꢡ
ꢬ
ꢤ
ꢣ
ꢩ
ꢫ
ꢨ
ꢨ
ꢠ
ꢡ
ꢵ
ꢯ
ꢣ
ꢫ
ꢨ
ꢡ
ꢣ
ꢧ
ꢡ
ꢫ
ꢩ
ꢫ
ꢨ
ꢨ
ꢦ
ꢤ
ꢠ
ꢮ
ꢴ
ꢠ
ꢡ
ꢩ
ꢮ
ꢪ
ꢯ
ꢫ
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443 • HOUSTON, TEXAS 77001