74VHC245 Octal Bidirectional Transceiver with 3-STATE Outputs
November 1992
Revised March 1999
74VHC245
Octal Bidirectional Transceiver with 3-STATE Outputs
General Description
The VHC245 is an advanced high speed CMOS octal bus
transceiver fabricated with silicon gate CMOS technology.
It achieves high speed operation similar to equivalent Bipo-
lar Schottky TTL while maintaining the CMOS low power
dissipation. The VHC245 is intended for bidirectional asyn-
chronous communication between data busses. The direc-
tion of data transmission is determined by the level of the
T/R input. The enable input can be used to disable the
device so that the busses are effectively isolated. All inputs
are equipped with protection circuits against static dis-
charge.
Features
s
High Speed: t
PD
=
4.0 ns (typ) at V
CC
=
5V
s
High Noise Immunity: V
NIH
=
V
NIL
=
28% V
CC
(Min)
s
Power Down Protection is provided on all inputs
s
Low Noise: V
OLP
=
0.9V (typ)
s
Low Power Dissipation:
I
CC
=
4
碌A(chǔ)
(Max) @ T
A
=
25擄C
s
Pin and Function Compatible with 74HC245
Ordering Code:
Order Number
74VHC245M
74VHC245SJ
74VHC245MTC
74VHC245N
Package Number
M20B
M20D
MTC20
N20A
Package Description
20-Lead Small Outline Integrated Package (SOIC), JEDEC MS-013, 0.300鈥?Wide
20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
20-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide
20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300鈥?Wide
Surface mount packages are also available on Tape and Reel. Specify by appending the suffix letter 鈥淴鈥?to the ordering code.
Logic Symbol
IEEE/IEC
Connection Diagram
Pin Description
Pin
Names
OE
T/R
A
0
鈥揂
7
B
0
鈥揃
7
Output Enable Input
Transmit/Receive Input
Side A Inputs or 3-STATE Outputs
Side B Inputs or 3-STATE Outputs
Description
Truth Table
Inputs
OE
L
L
H
T/R
L
H
X
Bus B Data to Bus A
Bus A Data to Bus B
HIGH-Z State
Outputs
H
=
HIGH Voltage Level L
=
LOW Voltage Level X
=
Immaterial
Any unused bus terminals during HIGH-Z State must be held HIGH or
LOW.
漏 1999 Fairchild Semiconductor Corporation
DS011520.prf
www.fairchildsemi.com
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