BU8874 Ver la hoja de datos (PDF) - ROHM Semiconductor

Número de pieza

componentes Descripción

Fabricante

BU8874

DTMF receiver for telephones

ROHM Semiconductor 

Communication ICs

FApplication example

BU8874 / BU8874F

FSelecting attachment components

(1) Power supply components

(2) Oscillation components

C502 : This is the VDD bypass capacitor, and is normally

100µF.

JP501 : This is normally shorted. To test the current con-

sumption of the IC (at the point where the power

down mode is entered), insert a DC ammeter in

place of JP501.

X501 :

Use a crystal or ceramic resonator with an os-

cillation frequency of 4.194304MHz. If using a

ceramic resonator, there may be problems with

the precision of the oscillation frequency, so we

recommend using one of the ceramic resona-

tors listed below.

C591 :

If you are using a dedicated resonator X501de-

signed for DTMF receivers, capacitor C591

should be left open. If you are injecting an exter-

nal clock, X501 should be omitted and DC

blocking capacitor C591 used in its place. Typi-

cally, this capacitor should be 47µnF.

208

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