74LV4060-Q100 データシートの表示（PDF） - Nexperia B.V. All rights reserved

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74LV4060-Q100

14-stage binary ripple counter with oscillator

Nexperia B.V. All rights reserved 

Nexperia

74LV4060-Q100

14-stage binary ripple counter with oscillator

14. RC oscillator

14.1 Timing component limitations

The oscillator frequency is mainly determined by Rt  Ct, provided R2  2Rt and R2  C2

is much less than Rt  Ct. The function of R2 is to minimize the influence of the forward

voltage across the input protection diodes on the frequency. The stray capacitance C2

should be kept as small as possible. In consideration of accuracy, Ct must be larger than

the inherent stray capacitance. Rt must be larger than the ‘ON’ resistance in series with it,

which typically is 280  at VCC = 1.2 V, 130  at VCC = 2.0 V and 100  at VCC 3.0 V. The

recommended values for these components to maintain agreement with the typical

oscillation formula are: Ct > 50 pF, up to any practical value, 10 k < Rt < 1 M. In order

to avoid start-up problems, Rt  1 k.

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Typical formula for oscillator frequency:

Fig 14. Example of an RC oscillator

fosc = 2----.-5---------R1----t--------C----t

DDD



IRVF

+]







DDL

5W



IRVF

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DDL

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VCC = 1.2 V to 3.6 V; Tamb = 25 C

Rt curve: Ct = 1 nF; R2 = 2  Rt

Fig 15. RC oscillator frequency as a function of Rt



 

 

 

 

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VCC = 1.2 V to 3.6 V; Tamb = 25 C

Ct curve: Rt = 100 k; R2 = 200 k

Fig 16. RC oscillator frequency as a function of Ct

74LV4060_Q100

Product data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 1 — 25 July 2014

© Nexperia B.V. 2017. All rights reserved

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