TECHNICAL DATA
Voice Switched Speakerphone Circuit
The
KK34118
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 receive 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
KK34118
may be operated from a power supply, or it can be powered
from the telephone line, requiring typically 5.0 mA. The
KK34118
can be
interfaced directly to Tip and Ring (through a coupling transformer) for
stand-alone operation, or it can be used in conjunction with a handset
speech network and or other features of a feature phone.
•
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 Defined Function
•
Dial Tone Detector to Inhibit Receive Idle Mode During Dial Tone
Presence
KK34118
ORDERING INFORMATION
KK34118N
Plastic
KK34118DW
SOIC
T
A
= -25° to 70° C for all packages
PIN ASSIGNMENT
1
KODENSHI [ KODENSHI KOREA CORP. ]
