5.6 Switching Characteristics

over recommended operating free-air temperature range, VCC = 5 V ± 0.5 V (unless otherwise noted) (see Section Parameter

Measurement Information section)

PARAMETER

TEST CONDITIONS

TA = 25°C

SN54AHCT240

–40°C to 85°C

SN74AHCT240

–40°C to 125°C

SN74AHCT240

UNIT

TYP

MAX

MIN

MAX

MIN

MAX

MIN

MAX

tPLH

Propagation delay

time

(low-to-high output)

A-to-Y

CL = 15 pF

5.4(1)

7.4(1)

1(1)

8.5(1)

1

8.5

1

9.5

ns

tPHL

Propagation delay

time

(high-to-low output)

5.4(1)

7.4(1)

1(1)

8.5(1)

1

8.5

1

9.5

tPZH

Enable time

(to the high level)

OE-to-Y

CL = 15 pF

7.7(1)

10.4(1)

1(1)

12(1)

1

12

1

13

ns

tPZL

Enable time

(to the low level)

7.7(1)

10.4(1)

1(1)

12(1)

1

12

1

13

tPHZ

Disable time

(from high level)

OE-to-Y

CL = 15 pF

8.3(1)

10.4(1)

1(1)

12(1)

1

12

1

13

ns

tPLZ

Disable time

(from low level)

8.3(1)

10.4(1)

1(1)

12(1)

1

12

1

13

tPLH

Propagation delay

time

(low-to-high output)

A-to-Y

CL = 50 pF

5.9

8.4

1

9.5

1

9.5

1

10.5

ns

tPHL

Propagation delay

time

(high-to-low output)

5.9

8.4

1

9.5

1

9.5

1

10.5

tPZH

Enable time

(to the high level)

OE-to-Y

CL = 50 pF

8.2

11.4

1

13

1

13

1

14

ns

tPZL

Enable time

(to the low level)

8.2

11.4

1

13

1

13

1

14

tPHZ

Disable time

(from high level)

OE-to-Y

CL = 50 pF

8.8

11.4

1

13

1

13

1

14

ns

tPLZ

Disable time

(from low level)

8.8

11.4

1

13

1

13

1

14

tsk(o)

Skew (time), output

CL = 50 pF

1(2)

1

1

1

ns

(1)

On products compliant to MIL-PRF-38535, this parameter is not production tested.

(2)

On products compliant to MIL-PRF-38535, this parameter does not apply.

5.7 Noise Characteristics

VCC = 5 V, CL = 50 pF, TA = 25°C(1)

PARAMETER

SN74AHCT240

UNIT

MIN

TYP

MAX

VOH(V)

Quiet output, minimum dynamic VOH

4.1

V

VIH(D)

High-level dynamic input voltage

2

V

VIL(D)

Low-level dynamic input voltage

0.8

V

(1)

Characteristics are for surface-mount packages only.

5.8 Operating Characteristics

VCC = 5 V, TA = 25°C

PARAMETER

TEST CONDITIONS

TYP

UNIT

Cpd

Power dissipation capacitance

No load, f = 1 MHz

10

pF

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