MC74HC244 ONSEMI [ON Semiconductor], MC74HC244 Datasheet - Page 4

• Manufacturer Part Number: MC74HC244
• Description: Octal 3-State Noninverting Buffer/Line Driver/Line Receiver
• Manufacturer: ONSEMI [ON Semiconductor]

INPUTS
A1, A2, A3, A4, B1, B2, B3, B4
(Pins 2, 4, 6, 8, 11, 13, 15, 17)
form on the corresponding Y outputs, when the outputs are
enabled.
CONTROLS
Enable A, Enable B (Pins 1, 19)
to these pins, the outputs are enabled and the devices
DATA INPUT
Data input pins. Data on these pins appear in noninverted
Output enables (active–low). When a low level is applied
YA OR YB
OUTPUT
A OR B
*Includes all probe and jig capacitance
t PLH
DEVICE
UNDER
t r
TEST
Figure 3. Test Circuit
t TLH
10%
10%
50%
50%
90%
90%
OUTPUT
Figure 1.
TEST POINT
C L *
t f
t PHL
SWITCHING WAVEFORMS
t THL
V CC
GND
PIN DESCRIPTIONS
http://onsemi.com
TEST CIRCUITS
MC74HC244A
4
OUTPUT Y
OUTPUT Y
DEVICE
UNDER
function as noninverting buffers. When a high level is
applied, the outputs assume the high impedance state.
OUTPUTS
YA1, YA2, YA3, YA4, YB1, YB2, YB3, YB4
(Pins 18, 16, 14, 12, 9, 7, 5, 3)
output–enable pins, these outputs are either noninverting
outputs or high–impedance outputs.
TEST
ENABLE
A OR B
Device outputs. Depending upon the state of the
*Includes all probe and jig capacitance
OUTPUT
50%
Figure 4. Test Circuit
TEST POINT
50%
50%
t PZL
t PZH
C L *
Figure 2.
1 k
t PHZ
t PLZ
CONNECT TO V CC WHEN
TESTING t PLZ AND t PZL .
CONNECT TO GND WHEN
TESTING t PHZ AND t PZH .
10%
90%
V CC
GND
HIGH
IMPEDANCE
V OL
V OH
HIGH
IMPEDANCE