Philips Semiconductors Product specification
74F655A*
74F656A
Buffers/drivers
74F655A Octal buffer/driver with parity, inverting (3-State)
74F656A Octal buffer/driver with parity, non-inverting (3-State)
2
1991 Jul 17 853-0383 03305
* Discontinued part. Please see the Discontinued Products List.
FEA TURES
•Significantly improved AC performance over 74F655 and 74F656
•High impedance NPN base input for reduced loading
(40µA in High and Low states)
•Ideal in applications where high output drive and light bus loading
are required (I
IL
is 40µA vs. FAST std of 600µA)
•74F655A combines 74F240 and 74F280A functions in one
package
•74F656A combines 74F244 and 74F280A functions in one
package
•74F655A Inverting
•74F656A Non-inverting
•3-State outputs sink 64mA and source 15mA
•24-pin plastic Slim DIP (300mil) package
•Inputs on one side and outputs on the other side simplifies PC
board layout
•Combined functions reduce part count and enhance system
performance
•Industrial temperature range available (–40°C to +85°C)
DESCRIPTION
The 74F655A and 74F656A are octal buffers and line drivers with
parity generation/checking designed to be employed as memory
address drivers, clock drivers and bus-oriented
transmitters/receivers. These parts include parity generator/checker
to improve PC board density.
TYPE
TYPICAL
PROPAGATION
DELA Y
TYPICAL SUPPL Y CURRENT
(TOT AL)
74F655A 6.5ns 64mA
74F656A 6.5ns 64mA
ORDERING INFORMATION
DESCRIPTION
COMMERCIAL RANGE
V
CC
= 5V ±10%,
T
amb
= 0°C to +70°C
INDUSTRIAL RANGE
V
CC
= 5V ±10%,
T
amb
= –40°C to +85°C
PKG DWG #
24-pin Plastic Slim
DIP (300mil)
N74F656AN I74F656AN SOT222-1
24-pin Plastic SOL N74F656AD I74F656AD SOT137-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS DESCRIPTION
74F(U.L.)
HIGH/LOW
LOAD VALUE
HIGH/LOW
D0–D7 Data inputs 2.0/0.066 40µA/40µA
PI Parity input 1.0/0.033 20µA/20µA
OE0, OE1, OE2 Output Enable Inputs (active Low) 1.0/0.033 20µA/20µA
ΣE, ΣO Parity outputs 750/106.7 15mA/64mA
Q0–Q7 Data outputs (74F655A) 750/106.7 15mA/64mA
Q0–Q7 Data outputs (74F656A) 750/106.7 15mA/64mA
NOTE: One (1.0) FAST Unit Load (U.L.) is defined as: 20µA in the High state and 0.6mA in the Low state.