UBA2050 Ver la hoja de datos (PDF) - Philips Electronics
Número de pieza
componentes Descripción
Fabricante
UBA2050 Datasheet PDF : 52 Pages
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Philips Semiconductors
One-chip telephone ICs with speech,
dialler and ringer functions
Product specification
UBA2050(A); UBA2051(A;C)
handbook, full pagewidth
Zline
GND
LN
RCC
Z bal
RSLPE
Im
IR
Zir
Rast1
RA
SLPE
MGT047
Fig.17 Equivalent circuit of an anti-sidetone network in a Wheatstone bridge configuration.
Dialler and ringer parts
SUPPLY VOLTAGE (PIN VDD)
The power supply must be maintained for repertory
memory retention (standby supply voltage) and may drop
down to 1.0 V, being the minimum value of the memory
retention voltage VMR. Applying a large capacitor across
the supply terminals can retain the memory when power
connections are broken.
The minimum operating voltage is 2.0 V (the Power-on
reset voltage VPOR has its maximum value). Below this
value, the internal Power-on reset disables the IC.
A memory integrity check is performed at each start-up.
In the event of a failing check, the memory is cleared.
By connecting a capacitor with a value of a few pico-farad
in parallel with the resonator, the oscillator frequency can
be decreased. By connecting a capacitor with a value of a
few ten pico-farad in series with the resonator, the
oscillator frequency can be increased. The oscillator starts
when VDD reaches the operating voltage level VPOR and
pin CE/FDI or pin CE/CSI goes HIGH.
Recommended resonator types: Murata
CSA 3.58MG300FGA or CSAC 3.58MGC300FGA.
OSCILLATOR (PIN XTAL)
The UBA205xx uses an on-chip oscillator as the master
timing source. It needs to be completed by an external
3.579545 MHz quartz crystal or ceramic resonator
connected between pins XTAL and GND. When using an
external ceramic resonator, additional components may
be required depending upon the ceramic resonator
specifications (refer to the product type specification).
2000 May 19
17
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