Speech/handsfree. TEA1099H Datasheet
Speech and handsfree IC with
auxiliary inputs/outputs and analog
Supersedes data of 1998 Jun 11
File under Integrated Circuits, IC03
1999 Apr 08
Speech and handsfree IC with auxiliary
inputs/outputs and analog multiplexer
• Low DC line voltage
• Voltage regulator with adjustable DC voltage
• Symmetrical high impedance inputs (70 kΩ) for
dynamic, magnetic or electret microphones
• Dual Tone Multi-Frequency (DTMF) input with
confidence tone on earphone and/or loudspeaker
• Receive amplifier for dynamic, magnetic or
piezo-electric earpieces (with externally adjustable gain)
• AGC: Automatic Gain Control for true line loss
• Provides a strong 3.35 V regulated supply for
microcontroller or dialler
• Provides filtered power supply, optimized according to
line current and compatible with external voltage or
• Filtered 2.0 V power supply output for electret
• Compatible with a ringer mode
• Power-Down (PD) logic input for power-down.
• Asymmetrical high-impedance input for electret
• Loudspeaker amplifier with single-ended rail-to-rail
output and externally adjustable gain
• Dynamic limiter on loudspeaker amplifier to prevent
• Logarithmic volume control on loudspeaker amplifier via
• 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
– Voice switch control (with adjustable switching range
and constant sum of gain during switching).
• General auxiliary output for transmit and receive
• Auxiliary transmit input with high signal level capability
dedicated to line transmission
• Auxiliary receive input with high signal level capability
• Integrated multiplexer for channels selection.
• Line powered telephone sets
• Cordless telephones
• Fax machines
• Answering machines.
The TEA1099H is an analog bipolar circuit dedicated for
telephone applications. It includes a line interface, handset
(HS) microphone and earpiece amplifiers, handsfree (HF)
microphone and loudspeaker amplifiers, some specific
auxiliary Inputs/Outputs (I/Os) and an analog multiplexer
to enable the right transmit and/or receive channels.
The multiplexer is controlled by a logic circuit which
decodes four logic inputs provided by a microcontroller.
Thirteen different application modes have been defined
and can be accessed by selecting the right logic inputs.
An application mode is a special combination of transmit
and receive channels required by telephone applications.
This IC can be supplied by the line and/or by the mains if
available (in a cordless telephone or an answering
machine for example). It provides a 3.35 V supply for a
microcontroller or dialler and a 2.0 V filtered voltage supply
for an electret microphone. The IC is designed to facilitate
the use of the loudspeaker amplifier during ringing phase.
1999 Apr 08