SDFS065A − D2932, MARCH 1987 − REVISED OCTOBER 1993
2−3
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
POST OFFICE BOX 1443 • HOUSTON, TEXAS 77251−1443
recommended operating conditions
SN54F257 SN74F257
MIN NOM MAX MIN NOM MAX
VCC Supply voltage 4.5 5 5.5 4.5 5 5.5 V
VIH High-level input voltage 2 2 V
VIL Low-level input voltage 0.8 0.8 V
IIK Input clamp current −18 −18 mA
IOH High-level output current −3 −3 mA
IOL Low-level output current 20 24 mA
TAOperating free-air temperature −55 125 0 70 °C
electrical characteristics over recommended operating free-air temperature range (unless
otherwise noted)
SN54F257 SN74F257
MIN TYP†MAX MIN TYP†MAX
VIK VCC = 4.5 V, II = −18 mA −1.2 −1.2 V
IOH = − 1 mA 2.5 3.4 2.5 3.4
VOH VCC = 4.5 V IOH = − 3 mA 2.4 3.3 2.4 3.3 V
VCC = 4.75 V, IOH = − 1 mA to −3 mA 2.7
IOL = 20 mA 0.3 0.5
VOL VCC = 4.5 V IOL = 24 mA 0.35 0.5 V
IOZH VCC = 5.5 V, VO = 2.7 V 50 50 µA
IOZL VCC = 5.5 V, VO = 0.5 V −50 −50 µA
IIVCC = 5.5 V, VI = 7 V 0.1 0.1 mA
IIH VCC = 5.5 V, VI = 2.7 V 20 20 µA
IIL VCC = 5.5 V, VI = 0.5 V − 0.6 − 0.6 mA
IOS‡VCC = 5.5 V, VO = 0 −60 −150 −60 −150 mA
ICCH
Condition A 9 15 9 15
ICCL VCC = 5.5 V,
Condition B 14.5 22 14.5 22 mA
ICCZ
Condition C 15 23 15 23
†All typical values are at VCC = 5 V, TA = 25°C.
‡Not more than one output should be shorted at a time, and the duration of the short circuit should not exceed one second.
NOTE 2: ICC is measured with the outputs open under the following conditions:
A. A/B and all B inputs at 4.5 V, other inputs grounded
B. All B inputs at 4.5 V, other inputs grounded
C. OE and all B data inputs at 4.5 V, other inputs grounded