MC33219AP DIP24 (MOTOROLA) Voice switched speakerphone

The Motorola MC33219A 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. The

volume control can be implemented with a potentiometer.

The MC33219A can be operated from a power supply, or from the

telephone line, requiring typically 3.2 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.

The MC33219A is available in a 24 pin narrow body DIP, and a wide body

SOIC package.

• Supply Voltage Range: 2.7 to 6.5 V

• Attenuator Range: 53 dB

• Background Noise Monitor for Each Path

• 2 Point Signal Sensing

• Volume Control Range: Typically 40 dB

• Microphone and Receive Amplifiers Pinned Out for Flexibility

• Microphone Amplifier can be Muted

• Mute and Chip Disable are Logic Level Inputs

• Chip Deselect Pin Powers Down the Entire IC

• Ambient Operating Temperature: –40 to +85°C

• 24 Pin Narrow Body (300 mil) DIP and 24 Pin SOIC