Nexperia

74HC240; 74HCT240

Octal buffer/line driver; 3-state; inverting

10. Dynamic characteristics

Table 7. Dynamic characteristics

GND = 0 V; for test circuit see Fig. 8.

25 °C

-40 °C to

+85 °C

-40 °C to

+125 °C

Symbol Parameter

Conditions

Min Typ Max Min

Max

Min

Max

Unit

74HC240

nAn to nYn; see Fig. 6

[1]

VCC = 2.0 V

-

30 100

-

125

-

150 ns

VCC = 4.5 V

-

11

20

-

25

-

30

ns

VCC = 5.0 V; CL = 15 pF

-

9

-

-

-

-

-

ns

tpd

propagation delay

VCC = 6.0 V

-

9

17

-

21

-

26

ns

nOE to nYn; see Fig. 7

[2]

VCC = 2.0 V

-

39 150

-

190

-

225 ns

VCC = 4.5 V

-

14

30

-

38

-

45

ns

ten

enable time

VCC = 6.0 V

-

11

26

-

33

-

38

ns

nOE to nYn or see Fig. 7

[3]

VCC = 2.0 V

-

41 150

-

190

-

225 ns

VCC = 4.5 V

-

15

30

-

38

-

45

ns

tdis

disable time

VCC = 6.0 V

-

12

26

-

33

-

38

ns

see Fig. 6

[4]

VCC = 2.0 V

-

14

60

-

75

-

90

ns

VCC = 4.5 V

-

5

12

-

15

-

18

ns

tt

transition time

VCC = 6.0 V

-

4

10

-

13

-

15

ns

CPD

power dissipation

capacitance

per buffer; VI = GND to VCC

[5]

-

30

-

-

-

-

-

pF

74HCT240

nAn to nYn; see Fig. 6

[1]

VCC = 4.5 V

-

11

20

-

25

-

30

ns

tpd

propagation delay

VCC = 5.0 V; CL = 15 pF

-

9

-

-

-

-

-

ns

ten

enable time

nOE to nYn; VCC = 4.5 V;

see Fig. 7

[2]

-

13

30

-

38

-

45

ns

tdis

disable time

nOE to nYn; VCC = 4.5 V;

see Fig. 7

[3]

-

13

25

-

31

-

38

ns

tt

transition time

VCC = 4.5 V; see Fig. 6

[4]

-

5

12

-

15

-

18

ns

CPD

power dissipation

capacitance

per buffer; VI = GND to VCC - 1.5 V [5] -

30

-

-

-

-

-

pF

[1] tpd is the same as tPHL and tPLH.

[2] ten is the same as tPZH and tPZL.

[3] tdis is the same as tPHZ and tPLZ.

[4] tt is the same as tTHL and tTLH.

[5] CPD is used to determine the dynamic power dissipation (PD in μW): PD = CPD × VCC 2 × fi × N + Σ (CL × VCC 2 × fo) where:

fi = input frequency in MHz;

fo = output frequency in MHz;

CL = output load capacitance in pF;

VCC = supply voltage in V;

N = number of inputs switching;

Σ (CL × VCC 2 × fo) = sum of outputs.

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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