Philips Semiconductors
Versatile telephone transmission circuit
with dialler interface
Product specification
TEA1068
FEATURES
• Voltage regulator with adjustable static resistance
• Provides supply for external circuitry
• Symmetrical high-impedance inputs (64 kΩ) for
dynamic, magnetic or piezoelectric microphones
• Asymmetrical high-impedance input (32 kΩ) for electret
microphone
• Dual-Tone Multi-Frequency (DTMF) signal input with
confidence tone
• Mute input for pulse or DTMF dialling
• Power down input for pulse dial or register recall
• Receiving amplifier for magnetic, dynamic or
piezoelectric earpieces
• Large gain setting range on microphone and earpiece
amplifiers
• Line current-dependent line loss compensation facility
for microphone and earpiece amplifiers
• Gain control adaptable to exchange supply
• DC line voltage adjustment facility.
GENERAL DESCRIPTION
The TEA1068 is a bipolar integrated circuit performing all
speech and line interface functions required in fully
electronic telephone sets. It performs electronic switching
between dialling and speech.
QUICK REFERENCE DATA
SYMBOL
VLN
Iline
ICC
VCC
Gv
∆Gv
Vexch
Rexch
Tamb
PARAMETER
CONDITIONS
line voltage
line current
Iline = 15 mA
TEA1068
normal operation
TEA1068T
normal operation
internal supply current
power down; input LOW
power down; input HIGH
supply voltage for peripherals
Iline = 15 mA;
MUTE = HIGH
voltage gain
Ip = 1.2 mA
Ip = 1.7 mA
microphone amplifier
receiving amplifier
line loss compensation gain control range
exchange supply voltage
exchange feeding bridge resistance range
ambient operating temperature
MIN. TYP. MAX. UNIT
4.2 4.45 4.7 V
10 −
140 mA
10 −
100 mA
−
0.96 1.3 mA
−
55 82 µA
2.8 3.05 −
V
2.5 −
−
V
44 −
17 −
5.5 5.9
24 −
0.4 −
−25
60 dB
39 dB
6.3 dB
60 V
1
kΩ
+75 °C
ORDERING INFORMATION
TYPE
NUMBER
TEA1068
TEA1068T
NAME
DIP18
SO20
PACKAGE
DESCRIPTION
plastic dual in-line package; 18 leads (300 mil)
plastic small outline package; 20 leads; body width 7.5 mm
VERSION
SOT102-1
SOT163-1
1996 Apr 23
2