Nexperia

74HC390; 74HCT390

Dual decade ripple counter

10.1. Waveforms and test circuit

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tW

VI

GND

VOH

VOL

10 %

90 %

90 %

10 %

VM

VM

1/fmax

tPLH

tPHL

tTLH

tTHL

nCPn input

nQn output

Measurement points are given in Table 9.

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

Fig. 5. The clock input (nCPn) to output (nQn) propagation delays, output transition time, clock pulse width and

maximum clock frequency

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tPHL

tW

trec

VM

VI

GND

nCPn input

VOH

VOL

nQn output

VM

VM

GND

nMR input

VI

Measurement points are given in Table 9.

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

Fig. 6. The master reset (nMR) pulse width, master reset to output (nQn) propagation delays and master reset to

clock (nCPn) recovery time

Table 9. Measurement points

Input

Output

Type

VM

VM

74HC390

0.5VCC

0.5VCC

74HCT390

1.3 V

1.3 V

74HC_HCT390

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© Nexperia B.V. 2021. All rights reserved

Product data sheet

Rev. 5 — 18 October 2021

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