Nexperia

74HC240; 74HCT240

Octal buffer/line driver; 3-state; inverting

5. Pinning information

5.1. Pinning

74HC240

74HCT240

1OE

VCC

1A0

2OE

2Y0

1Y0

1A1

2A0

2Y1

1Y1

1A2

2A1

2Y2

1Y2

1A3

2A2

2Y3

1Y3

GND

2A3

001aag233

1

2

3

4

5

6

7

8

9

10

12

11

14

13

16

15

18

17

20

19

Fig. 4. Pin configuration SOT163-1 (SO20) and

SOT360-1 (TSSOP20)

001aag234

74HC240

74HCT240

Transparent top view

1Y3

1A3

2Y3

GND(1)

2A2

2Y2

1Y2

1A2

2A1

2Y1

1Y1

1A1

2A0

2Y0

1Y0

1A0

2OE

9

12

8

13

7

14

6

15

5

16

4

17

3

18

2

19

terminal 1

index area

(1) This is not a ground pin. There is no electrical or

mechanical requirement to solder the pad. In case

soldered, the solder land should remain floating or

connected to GND.

Fig. 5. Pin configuration SOT764-1 (DHVQFN20)

5.2. Pin description

Table 2. Pin description

Symbol

Pin

Description

1OE, 2OE

1, 19

output enable input (active LOW)

1A0, 1A1, 1A2, 1A3

2, 4, 6, 8

data input

2Y0, 2Y1, 2Y2, 2Y3

3, 5, 7, 9

bus output

GND

10

ground (0 V)

2A0, 2A1, 2A2, 2A3

17, 15, 13, 11

data input

1Y0, 1Y1, 1Y2, 1Y3

18, 16, 14, 12

bus output

VCC

20

supply voltage

6. Functional description

Table 3. Function table

H = HIGH voltage level; L = LOW voltage level; X = don’t care; Z = high-impedance OFF-state.

Input

Output

nOE

nAn

nYn

L

L

H

L

H

L

H

X

Z

74HC_HCT240

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© Nexperia B.V. 2021. All rights reserved

Product data sheet

Rev. 6 — 2 September 2021

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