ET- IL34118
Voice Switched Speakerphone Circuit
The IL34118 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 adjustable gain and MUTE control, Transmit and Receive
attenuators which operate in a complementary manner, level detectors
at both input and output of both attenuators, and background noise
monitors for both the transmit and receive channels. A Dial Tone
Detector prevents the dial tone from being attenuated by the Receive
background noise monitor circuit. Also included are two line driver
amplifiers which can be used to form a hybrid network in conjunction
with an external coupling transformer. A high pass filter can be used
to filter out 60 Hz noise in the reseive channel, or for other filtering
functions. A Chip Disable pin permits powering down the entire
circuit to conserve power on long loops where loop current is at a
minimum.
The IL34118 may be operated from a power supply, or it can be
ORDERING INFORMATION
powered from the telephone line, requiring typically 5.0 mA. The
IL34118N Plastic
IL34118 can be interfaced directly to Tip and Ring (through a
IL34118DW SOIC
coupling transformer) for stand-alone operation, or it can be used in
T
A
= -25° to 70° C for all packages
conjunction with a handset speech network and or other features of a
featurephone.
•
Improved Attenuator Gain Range: 52 dB Between Transmit and
Receive
•
Low Voltage Operation for Line-Powered Applications (3.0-
6.5 V)
•
4 Point Signal Sensing for Improved Sensitivity
•
Background Noise Monitors for Both Transmit and Receive
Paths
•
Microphone Amplifier Gain Set by External Resistors - Mute
Function Included
•
Chip Disable for Active Standby Operation
•
On Board Filter Pinned-Out for User Deined Function
•
Dial Tone Detector to Inhibit Receive Idle Mode During Dial
Tone Presence
PIN ASSIGNMENT
1
BEIJING ESTEK ELECTRONICS CO.,LTD
ESTEK [ Estek Electronics Co. Ltd ]
