Nexperia

74HC240; 74HCT240

Octal buffer/line driver; 3-state; inverting

10.1. Waveforms and test circuit

nAn input

nYn output

tPHL

tPLH

GND

VI

VM

VM

VM

VM

VOH

VOL

90 %

10 %

10 %

90 %

tTHL

tTLH

mgu781

Measurement points are given in Table 8.

VOL and VOH are typical voltage output levels that occur with the output load.

Fig. 6. Input (nAn) to output (nYn) propagation delays and output transition times

001aae014

tPLZ

tPHZ

outputs

disabled

outputs

enabled

VY

VX

outputs

enabled

nYn output

LOW-to-OFF

OFF-to-LOW

nYn output

HIGH-to-OFF

OFF-to-HIGH

nOE input

VI

VOL

VOH

VCC

VM

GND

GND

tPZL

tPZH

VM

VM

Measurement points are given in Table 8.

VOL and VOH are typical voltage output levels that occur with the output load.

Fig. 7. 3-state enable and disable times

Table 8. Measurement points

Input

Output

Type

VM

VM

VX

VY

74HC240

0.5 × VCC

0.5 × VCC

0.1 × VCC

0.9 × VCC

74HCT240

1.3 V

1.3 V

0.1 × VCC

0.9 × VCC

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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