MC33215 Ver la hoja de datos (PDF) - Motorola => Freescale

Número de pieza

componentes Descripción

Lista de partido

MC33215

Telephone Line Interface and Speakerphone Circuit

Motorola => Freescale 

Freescale SMeCm3i3c2o15nductor, Inc.

Table 3. Logic Table for Switch–Over

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁTÁÁÁÁÁÁSE>11000ÁÁÁÁÁÁRSÁÁÁÁÁÁE ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁTSEÁÁÁÁÁÁ>TÁÁÁÁÁÁBXXX10NÁÁÁÁÁÁ+13ÁÁÁÁÁÁmVÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁRÁÁÁÁÁÁSE>ÁÁÁÁÁÁXX100VDÁÁÁÁÁÁDT ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁRSÁÁÁÁÁÁE>RÁÁÁÁÁÁBXXX10NÁÁÁÁÁÁ+13ÁÁÁÁÁÁmVÁÁÁÁÁÁÁÁÁÁÁÁTIRRIddreellaeeccÁÁÁÁÁÁneesiimvveeÁÁÁÁÁÁit MÁÁÁÁÁÁodeÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

The resistors for the sensitivity setting have to be coupled

capacitively to the pins for dc decoupling, and also to create

a high pass filter to suppress low frequent background noises

like footsteps and 50 Hz.

The switch–over timing is performed by charging and

discharging the CSWT capacitor. The switch–over from

transmit to receive or vice versa is fast, on the order of

milliseconds, and is proportional to the value of CSWT. The

switch–over to idle mode is slow, in the order of a few

seconds, and is proportional to the product of the values of

RSWT and CSWT. Figure 16 depicts a typical switch–over

behavior when applying transmit and receive stimuli.

The electrical characteristics and the behavior of the

MC33215 are not the only factor in designing a handsfree

speakerphone. During the design the acoustics have to be

taken into account from the beginning. The choice of the

transducers and the design of the cabinet are of great

influence on the speakerphone performance. Also, to

achieve a proper handsfree operation, the fine tuning of the

components around the duplex controller have to be done

with the final choice of the cabinet and the transducers.

100.0E–3

10.0E–3

1.0E–3

100.0E–6

Figure 15. Compression Range of the Signal Monitors

Upper Limit of

Compression

100.0E–3

Dial Tone

Threshold

10.0E–3

Lower Limit of

Compression

1.0E–3

Upper Limit of

Compression

Lower Limit of

Compression

10.0E–6

100

1000

10000

RRSA (Ω)

A. Receive Monitor

100.0E–6

100000

100

1000

10000

RTSA (Ω)

B. Transmit Monitor

Figure 16. Switch–Over Behavior

100000

Receive

Transmit

SWT

VMC + 0.5

VMC – 0.5

16

For More Information On This ProdMuOcTtO, ROLA ANALOG IC DEVICE DATA

Go to: www.freescale.com

Share Link: