- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄360459 > 74HC257 (NXP Semiconductors N.V.) Quad 2-input multiplexer 3-state PDF資料下載
參數(shù)資料
| 型號： | 74HC257 |
| 廠商： | NXP Semiconductors N.V. |
| 英文描述： | Quad 2-input multiplexer 3-state |
| 中文描述： | 四2輸入復用器三態(tài) |
| 文件頁數(shù)： | 2/13頁 |
| 文件大小： | 80K |
| 代理商： | 74HC257 |
1998 Sep 30
2
Philips Semiconductors
Product specification
Quad 2-input multiplexer; 3-state
74HC/HCT257
FEATURES
Non-inverting data path
3-state outputs interface directly with system bus
Output capability: bus driver
I
CC
category: MSI
GENERAL DESCRIPTION
The 74HC/HCT257 are high-speed Si-gate CMOS devices
and are pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The 74HC/HCT257 have four identical 2-input multiplexers
with 3-state outputs, which select 4 bits of data from two
sources and are controlled by a common data select
input (S).
The data inputs from source 0 (1I
0
to 4I
0
) are selected
when input S is LOW and the data inputs from source 1
(1I
1
to 4I
1
) are selected when S is HIGH. Data appears at
the outputs (1Y to 4Y) in true (non-inverting) form from the
selected inputs.
The “257” is the logic implementation of a 4-pole,
2-position switch, where the position of the switch is
determined by the logic levels applied to S. The outputs
are forced to a high impedance OFF-state when OE is
HIGH.
The logic equations for the outputs are:
1Y = OE.(1I
1
.S
+
1I
0
.S)
2Y = OE.(2I
1
.S
+
2I
0
.S)
3Y = OE.(3I
1
.S
+
3I
0
.S)
4Y = OE.(4I
1
.S
+
4I
0
.S)
The “257” is identical to the “258” but has non-inverting
(true) outputs.
QUICK REFERENCE DATA
GND = 0 V; T
amb
= 25
°
C; t
r
= t
f
= 6 ns
Notes
1.
C
PD
is used to determine the dynamic power dissipation (P
D
in
μ
W):
P
D
= C
PD
×
V
CC2
×
i
+ ∑
(C
L
×
V
CC2
×
f
o
) where:
f
i
= input frequency in MHz
f
o
= output frequency in MHz
∑
(C
L
×
V
CC2
×
f
o
) = sum of outputs
C
L
= output load capacitance in pF
V
CC
= supply voltage in V
For HC the condition is V
I
= GND to V
CC
For HCT the condition is V
I
= GND to V
CC
1.5 V
2.
SYMBOL
PARAMETER
CONDITIONS
TYPICAL
UNIT
HC
HCT
t
PHL
/ t
PLH
propagation delay
nI
0
, nI
1
to nY
S to nY
input capacitance
power dissipation capacitance per multiplexer
C
L
= 15 pF; V
CC
= 5 V
11
14
3.5
45
13
17
3.5
45
ns
ns
pF
pF
C
I
C
PD
notes 1 and 2
相關PDF資料 |
PDF描述 |
|---|---|
| 74HCT257 | 3-state |
| 74HCT533LC | 8-Bit D-Type Latch |
| 74HCT534D | Octal D-Type Flip-Flop |
| 74HCT534D-T | Octal D-Type Flip-Flop |
| 74HCT534N | Octal D-Type Flip-Flop |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| 74HC257D | 功能描述:編碼器、解碼器、復用器和解復用器 QUAD 2-IN MUX 3STATE RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量（輸入/輸出）:2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray |
| 74HC257D,652 | 功能描述:編碼器、解碼器、復用器和解復用器 QUAD 2-IN MUX 3STATE RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量（輸入/輸出）:2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray |
| 74HC257D,653 | 功能描述:編碼器、解碼器、復用器和解復用器 QUAD 2-IN MULTIPLEXER 3-S RoHS:否 制造商:Micrel 產(chǎn)品:Multiplexers 邏輯系列:CMOS 位數(shù): 線路數(shù)量（輸入/輸出）:2 / 12 傳播延遲時間:350 ps, 400 ps 電源電壓-最大:2.625 V, 3.6 V 電源電壓-最小:2.375 V, 3 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:QFN-44 封裝:Tray |
| 74HC257D/AUJ | 制造商:NXP Semiconductors 功能描述:74HC257D/SO16/REEL13//AU - Tape and Reel 制造商:NXP Semiconductors 功能描述:IC DATA SELECTOR/MUX SGL 16SOIC |
| 74HC257D/S410,118 | 制造商:NXP Semiconductors 功能描述:- Tape and Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復。