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Freescale Semiconductor, Inc.
this document by MC33218A/D
Advance Information
Voice Switched Speakerphone
with Microprocessor Interface
The Motorola MC33218A Voice Switched Speakerphone Circuit
incorporates the necessary amplifiers, attenuators, level detectors, and
control algorithm to form the heart of a high quality hands–free
speakerphone system. Included are a microphone amplifier with mute,
transmit and receive attenuators, a background monitoring system for both
the transmit and receive paths, and level detectors for each path. An AGC
system reduces the receive gain on long lines where loop current and power
are in short supply. A dial tone detector prevents fading of dial tone. A Chip
Disable pin permits conserving power when the circuit is not in use.
Additionally, the MC33218A has a serial data port which permits
microprocessor control of the receive volume level, microphone mute,
attenuator range, and selection of transmit, receive, idle or normal modes.
The data port can be operated at up to 1.0 MHz.
The MC33218A can be operated from a power supply, or from the
telephone line, requiring typically 4.6 mA. It can be used in conjunction with a
variety of speech networks. Applications include not only speakerphones,
but intercoms and other voice switched devices.
•
Supply Voltage Range: 2.7 to 6.5 V
MC33218A
VOICE SWITCHED
SPEAKERPHONE WITH
µPROCESSOR
INTERFACE
SEMICONDUCTOR
TECHNICAL DATA
Freescale Semiconductor, Inc...
24
1
P SUFFIX
PLASTIC PACKAGE
CASE 724
•
•
•
24
1
Attenuator Range: 53 or 27 dB (Selectable)
2 Point Sensing with Background Noise Monitor in Each Path
Microprocessor Port for Control of:
Volume Control (40 dB Range over 16 Levels)
Mute Microphone Amplifier
Force to Receive, Transmit, or Idle Modes
Attenuator Range Selection (27 or 53 dB)
Chip Disable Pin Powers Down the Entire IC
24 Pin Narrow Body (300 mil) DIP and 24 Pin SOIC
DW SUFFIX
PLASTIC PACKAGE
CASE 751E
•
•
PIN CONNECTIONS
CP2
XDI
CPT
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
VCC
TAO
MCO
MCI
POR
DR
DATA
CLK
RXI
RXO
RAO
GND
Simplified Block Diagram
Microphone
Transmit
Out
VB
Receive
In
TLI
TLO
VB
CT
CD
VB
NC
CPR
RLI
VB
BNM
CLK
DATA
POR
DR
CD
VCC
VB
Serial
Port
Tx Attenuator
Attenuator Control
DTD
Rx Attenuator
BNM
VB
RLO
(Top View)
Reg.
MC33218A
ORDERING INFORMATION
Device
MC33218ADW
Operating
Temperature Range
TA = – 40° to +85°C
Package
SO–24L
Plastic DIP
Speaker
Speaker Amplifier
This device contains 610 active transistors.
MC33218AP
This document contains information on a new product. Specifications and information herein are
subject to change without notice.
©
Motorola, Inc. 1995
MOTOROLA ANALOG IC DEVICE DATA
For More Information On This Product,
Go to: www.freescale.com
1
FREESCALE [ FREESCALE SEMICONDUCTOR, INC ]
