MC54HC157A Motorola, MC54HC157A Datasheet - Page 4

• Manufacturer Part Number: MC54HC157A
• Description: Quad 2-Input Data Selectors / Multiplexers
• Manufacturer: Motorola

MOTOROLA
INPUTS
A0, A1, A2, A3 (Pins 2, 5, 11, 14)
ferred to the outputs when the Select input is at a low level
and the Output Enable input is at a low level. The data is
presented to the outputs in noninverted form.
B0, B1, B2, B3 (Pins 3, 6, 10, 13)
ferred to the outputs when the Select input is at a high level
and the Output Enable input is at a low level. The data is
presented to the outputs in noninverted form.
OUTPUTS
Y0, Y1, Y2, Y3 (Pins 4, 7, 9, 12)
MC54/74HC157A
Nibble A inputs. The data present on these pins is trans-
Nibble B inputs. The data present on these pins is trans-
Data outputs. The selected input Nibble is presented at
INPUT A OR B
OUTPUT Y
t PLH
t r
t TLH
10%
Figure 1. HC157A
50%
10%
50%
90%
90%
OUTPUT Y
OUTPUT
ENABLE
t f
t PHL
* Includes all probe and jig capacitance
t PHL
SWITCHING WAVEFORMS
t THL
t THL
PIN DESCRIPTIONS
DEVICE
Figure 4. Test Circuit
UNDER
GND
V CC
TEST
10%
Figure 3. HC157A
50%
90%
90%
50%
t r
10%
4
OUTPUT
these outputs when the Output Enable input is at a low level.
The data present on these pins is in its noninverted form. For
the Output Enable input at a high level, the outputs are at a
low level.
CONTROL INPUTS
Select (Pin 1)
transferred to the outputs. A low level on this input selects
the A inputs and a high level selects the B inputs.
Output Enable (Pin 15)
selected input data to be presented at the outputs. A high
level on this input sets all outputs to a low level.
Nibble select. This input determines the data word to be
Output Enable input. A low level on this input allows the
TEST POINT
SELECT
OUTPUT Y
t f
C L *
t PLH
t TLH
Figure 2. Y versus Select, Noninverted
t PLH
t r
V CC
GND
t TLH
10%
50%
10%
90%
50%
90%
High–Speed CMOS Logic Data
t f
DL129 — Rev 6
t PHL
t THL
GND
V CC