KK34118 Datasheet, PDF (1/14 Pages) KODENSHI KOREA CORP. – Voice Switched Speakerphone Circuit

TECHNICAL DATA
Voice Switched Speakerphone Circuit
KK34118
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.
ORDERING INFORMATION
KK34118N Plastic
KK34118DW SOIC
T_A = -25° to 70° C for all packages
• 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
PIN ASSIGNMENT
1