Philips Semiconductors
Speech and handsfree IC
Product specification
TEA1098
FEATURES
Line interface
• Low DC line voltage
• Voltage regulator with adjustable DC voltage
• Symmetrical high impedance inputs (70 kΩ) for
dynamic, magnetic or electret microphones
• DTMF input with confidence tone on earphone and/or
loudspeaker
• Receive amplifier for dynamic, magnetic or
piezo-electric earpieces (with externally adjustable gain)
• Automatic Gain Control (AGC) for true line loss
compensation.
Supplies
• Provides a strong 3.35 V regulated supply for
microcontrollers or diallers
• Provides filtered power supply, optimized according to
line current
• Filtered 2.0 V power supply output for electret
microphone
• PD logic input for power-down.
Handsfree
• Asymmetrical high input impedance for electret
microphone
• Loudspeaker amplifier with single-ended rail-to-rail
output and externally adjustable gain
• Dynamic limiter on loudspeaker amplifier to prevent
distortion
• Logarithmic volume control on loudspeaker amplifier via
linear potentiometer
• Duplex controller consisting of:
– Signal and noise envelope monitors for both
channels (with adjustable sensitivities and timing)
– Decision logic (with adjustable switch-over and Idle
mode timing)
– Voice switch control (with adjustable switching range
and constant sum of gain during switching).
APPLICATIONS
• Line powered telephone sets.
GENERAL DESCRIPTION
The TEA1098 is an analog bipolar circuit dedicated to
telephony applications. It includes a line interface, handset
(HS) microphone and earpiece amplifiers, handsfree (HF)
microphone and loudspeaker amplifiers and a duplex
controller with signal and noise monitors on both channels.
This IC provides a 3.35 V supply for a microcontroller or
dialler and a 2.0 V filtered voltage supply for an electret
microphone.
ORDERING INFORMATION
TYPE
NUMBER
TEA1098TV
TEA1098H
NAME
VSO40
QFP44
TEA1098UH
−
PACKAGE
DESCRIPTION
plastic very small outline package; 40 leads
plastic quad flat package; 44 leads (lead length 1.3 mm);
body 10 × 10 × 1.75 mm
bare die; on foil
VERSION
SOT158-1
SOT307-2
−
1999 Oct 14
2