Unit LoadingFan Out

54F74F

Pin Names

Description

UL

HIGHLOW

Side A Data Inputs

1010

Side B Data Inputs

1010

Common Select Inputs

1010

Side A Output Enable Input (Active LOW)

1010

Side B Output Enable Input (Active LOW)

1010

TRI-STATE Outputs

15040(333)

b

3 mA24 mA (20 mA)

Functional Description

This device contains two identical 4-input multiplexers with

TRI-STATE outputs They select two bits from four sources

which when HIGH force the outputs to a high impedance

(High Z) state This device is the logic implementation of a

2-pole 4-position switch where the position of the switch is

determined by the logic levels supplied to the two select

inputs The logic equations for the outputs are shown below

If the outputs of TRI-STATE devices are tied together all

but one device must be in the high impedance state to avoid

high currents that would exceed the maximum ratings De-

signers should ensure that Output Enable signals to TRI-

STATE devices whose outputs are tied together are de-

signed so that there is no overlap

Truth Table

Select

Data Inputs

Output

Output

Inputs

Enable

OE

Z

X

X

XXXX

H

Z

L

L

L

XXX

L

L

L

L

H

XXX

L

H

H

L

XLX

X

L

L

H

L

XHX

X

L

H

L

H

X

XLX

L

L

L

H

X

XHX

L

H

H

H

XXX

L

L

L

H

H

XXX

H

L

H

Logic Diagram

TLF9505 – 4

Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays

2