Datasheet

UNISONIC TECHNOLOGIES CO., LTD
MC34018
LINEAR INTEGRATED CIRCUIT
VOICE SWITCHED
SPEAKER-PHONE CIRCUIT

DESCRIPTION
The UTC MC34018 speaker-phone integrated circuit includes
all the active circuitry and control functions to implement a high
quality hands-free telephone system. The circuit includes a
microphone amplifier, a speaker amplifier, level detectors, a
background sound level monitoring system in both the transmit and
receive channels and an attenuation system which can control the
transmit and receive levels as well as the background level.
The
applications
include
household
and
office
speaker-phones, intercom systems, hand free kit for mobile
phones, and others.

FEATURES
* Chip Select pin for Power conservation (active/standby mode).
* Integrated all necessary active circuitry for a hand-free telephone
into one single chip.
* Operating under wide dynamic range through signal compression
technology.
* Build-In voltage regulators illuminate external regulators for lining
operation.
* Monitoring system for background noise level.
* Background sound level compensation for transmit and
receive levels as well as the background level.
* Power audio amplifier for typical 100mW output (into 25Ω) with
peak limiting for speaker to minimize distortion.
* Volume control function for external volume control circuit.

ORDERING INFORMATION
Order Number
Lead Free
MC34018L-E28-T
-
Halogen Free
MC34018G-D28-T
MC34018G-E28-T
MC34018G-R28-T
MC34018G-R28-R
MC34018G-S28-T
MC34018G-S28-R
www.unisonic.com.tw
Copyright © 2014 Unisonic Technologies Co., Ltd
Package
Packing
DIP-28
SDIP-28
SSOP-28
SSOP-28
SOP-28
SOP-28
Tube
Tube
Tube
Tape Reel
Tube
Tape Reel
1 of 8
QW-R108-006.E
MC34018

LINEAR INTEGRATED CIRCUIT
MARKING
PACKAGE
MARKING
SOP-28
SSOP-28
DIP-28
SDIP-28

PIN CONFIGURATION
RR
RTX
TXI
TXO
TLI
TLO
RLI
RLO
MCI
MCO
CP1
CP2
XDI
SKG
1
2
3
4
5
6
7
8
9
10
11
12
13
14
UNISONIC TECHNOLOGIES CO., LTD
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28
27
26
25
24
23
22
21
20
19
18
17
16
15
RRX
RXI
RXO
ACF
VLC
XDC
GND
VB
VCC
SKI
CS
AGC
V+
SKO
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QW-R108-006.E
MC34018
LINEAR INTEGRATED CIRCUIT
PIN DESCRIPTION

PIN NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
PIN NAME
DESCRIPTION
RR
A resistor to ground provides a reference current for the transmit and receive attenuators
A resistor to ground determines the nominal gain of the transmit attenuator, the transmit
RTX
channel gain is inversely proportional to RTX resistance.
TXI
Transmit Attenuator Input, Input resistance is nominally 5.0kΩ.
Transmit Attenuator Output, The TXO output signal drivers the input of transmit level
TXO
detcetor, as well as the external circuit which drivers the telephone line.
Transmit Level detector Input. An external resistor ac coupled to The TLI pin sets the
TLI
detection level. Decreasing this resistor increases the sensitivity to transmit channel
signals.
Transmit Level detector Output. The external resistor and capacitor set the time the
TLO
comparator will hold the system in the transmit mode after speech ceases.
Receive Level detector Input. An external resistor ac coupled to The RLI pin sets the
RLI
detection level. Decreasing this resistor increases the sensitivity to receive channel signals.
Receive Level detector Output. The external resistor and capacitor set the time the
RLO
comparator will hold the system in the receive mode after speech ceases.
Microphone amplifier input. Input impedance is nominally 10kΩ and the dc bias voltage is
MCI
approximately equal to VB
MCO
Microphone amplifier output. The MIC amp gain is internally set at 34dB (50V/V).
A parallel resistor and capacitor connected between this pin and VCC holds a voltage
CP1
corresponding to the background noise level. The transmit detector compares the CP1
voltage with the speech signal from CP2.
A capacitor at this pin peak detects the speech signals for comparison with the background
CP2
noise level held at CP1.
Input to the transmit detector system. The microphone amplifier output is ac coupled to the
XDI
XDI pin through an external resistor.
High current ground pin for the speaker amplifier output stage. The SKG voltage should be
SKG
within 10mV of the ground voltage at pin 22.
Speaker amplifier output. The SKO pin will source and sink up to 100mA when ac coupled
SKO
to the speaker. The speaker amplifier gain is internally set at 34dB (50V/V).
Input DC supply voltage. V+ can be powered from Tip and Ring if an ac decoupling inductor
V+
is used to prevent loading ac line signals. The required V+ voltage is 6.0V to 11V (7.5V
nominal) at 7.0mA.
A capacitor from this pin to VB stabilizes the speaker amplifier gain control loop, and
additionally controls the attack and decay time of this circuit. The gain control loop limits the
AGC
speaker amplifier input to prevent clipping at SKO. The internal resistance at AGC pin is
nominally 110kΩ.
Digital chip select input. When at a logic "0" (<0.7V) the VCC regulator is enabled. When at
a logic "1" (>1.6V),the chip is in the standby mode drawing 0.5mA.An open CS pin is a logic
"0".Input impedance is nominally 140k ohms. The input voltage should not exceed 11V.
CS
SKI
Input to the speaker amplifier. Input impedance is nominally 20kΩ.
A 5.4V regulated output which powers all circuits except the speaker amplifier output stage.
VCC can be used to power external circuitry such as a microprocessor(3.0mA max.) A filter
capacitor is required. The UTC MC34018 can be powered by a separate regulated supply
VCC
by connecting V+ and VCC to a voltage between 4.5V and 6.5V while maintaining CS at a
logic "1".
An output voltage equal to approximately VCC/2 which series as an analog ground for the
VB
speakerphone system. Up to 1.5mA of external load current may be sourced from VB.
Output impedance is 250 ohms. A filter capacitor is required.
GND
Ground pin for the IC(except the speaker amplifier)
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3 of 8
QW-R108-006.E
MC34018

PIN DESCRIPTION(Cont.)
PIN NO.
PIN NAME
23
XDC
24
VLC
25
ACF
26
RXO
27
RXI
28
RRX
DESCRIPTION
Transmit detector output. A resistor and capacitor at his pin hold the system in the transmit
mode during pauses between words or phrases. When the XDC pin voltage decays to
ground, the attenuators switch from the transmit mode to idle mode. The internal resistor at
XDC is nominally 2.6k ohms(see Fig.1).
Volume control input>connecting this pin to the slider of a variable resistor provides receive
mode volume control. The VLC pin voltage should be less than or equal to VB.
Attenuator control filter. A capacitor connected to this pin reduces noise transient as the
attenuator control switches level of attenuation.
Receive attenuator Output. Normally this pin is ac coupled to the input of the speaker
amplifier.
Receive attenuator Input. Input impedance is nominally is 5.0kΩ.
A resistor to ground determines the nominal gain of the receive attenuator. The receive
channel gain is directly proportional to the RRX resistance.
BLOCK DIAGRAM
Speaker

LINEAR INTEGRATED CIRCUIT
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QW-R108-006.E
MC34018

LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATINGS (TA=25C, Voltage referred to pin 22.)
PARAMETER
SYMBOL
RATINGS
UNIT
V+ terminal Voltage (pin 16)
+12, -1.0
V
CS (pin 18)
+12, -1.0
V
Speaker amplifier Ground(pin 14)
+3.0, -1.0
V
VLC(pin 24)
+VCC, -1.0
V
Storage temperature
TSTG
-65 ~ +150
C
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.

RECOMMENDED OPERATION CONDITIONS
PARAMETER
V+ Terminal Voltage (pin 16)
CS (pin 18)
VLC (pin 24)
Receive Signal(pin 27)
Microphone Signal(pin 9)
Speaker Amplifier Ground (pin 14)
ICC (pin 20)
Ambient Temperature

SYMBOL
TA
UNIT
V
V
V
mVrms
mVrms
mVdc
mA
C
TYP CHANGE
-0.2
-0.4
+0.1
±0.003
±0.24
±0.001
±0.4
+0.4
±0.2
UNIT
%/C
%/C
%/C
dB/C
%/C
dB/C
dB/C
%/C
nA/C
TEMPERATURE CHARACTERISTICS (-20 ~+60C)
PARAMETER
V+ Supply Current ( V+ 11V,Pin 18 = 0.7V )
V+ Supply Current(V+ 11V,Pin 18 = 1.6V )
VCC Voltage( V+ = 7.5V )
Attenuator Gain ( Max and Min Setting )
Delta RXO,TXO Voltage
Speaker AMP Gain
Microphone AMP Gain
Microphone Amp Input Resistance
Tx-Rx Switching Threshold (20A)

RATINGS
+6.0 ~ +11
0 ~ +11
0.55VB ~ VB
0 ~ 250
0 ~ 5.0
-10 ~ +10
0 ~ 3.0
-20 ~ +60
PIN
16
16
20
4,26
15,19
9,10
9
5,7
ELECTRICAL CHARACTERISTICS (Referred to Fig.1)
PARAMETER
SUPPLY VOLTAGES
VCC Voltage
Line Regulation
Dropout Voltage
VB Voltage
SYMBOL
VCC
VCCLN
VD
VB
V+ Supply Current
IV+
Output Resistance
ROUT
ROUT
Output Resistance
ATTENUATORS
Receive Attenuator Gain
(1.0kHz)
Rx Mode, Pin 24= VB
Pin 27 = 250Mvrms
Range (Rx to Tx Modes)
Idle Mode, Pin 27= 250mVrms
TEST CONDITIONS
V+=7.5V
6.5V<V+<11V
V+=5.0V
V+=7.5V
V+=11V, Pin 18=0.7V
TYP
MAX
UNIT
4.9
5.4
65
80
2.9
5.9
150
300
3.3
9.0
Vdc
mV
mV
Vdc
mA
800
20
μA
Ω
2.5
V+=11V, Pin 18=1.6V
ICC=3mA
6.0
IB=1.7mA
250
Ω
GRX
2.0
6.0
10
dB
GRX
40
44
48
dB
GRI
-20
-16
-12
dB
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MIN
5 of 8
QW-R108-006.E
MC34018

LINEAR INTEGRATED CIRCUIT
ELECTRICAL CHARACTERISTICS (Cont.)
PARAMETER
RXO Voltage (Rx Mode)
Delta RXO Voltage
(Switch from Rx to Tx Mode)
RXO Sink Current (Rx mode)
RXO Source Current (Rx mode)
RXI Input Resistance
Volume Control Range
SYMBOL
VRXO
MIN
1.8
TYP
2.3
VRXO
IRXOL
IROXH
RRXI
VCR
ATTENUATORS
TXO Voltage (Tx mode)
Delta TXO Voltage (switch from Tc
to Rx Mode)
TEST CONDITIONS
75
1.0
3.5
Rx Attenuator Gain, Rx Mode,
0.6VB<Pin 24<VB
VTXO
5.0
24.5
1.8
2.3
VTXO
Rx Mode
Tx Mode
Idle Mode
MAX
3.2
UNIT
mV
100
mV
3.0
8.0
μA
mA
kΩ
32.5
dB
3.2
Vdc
100
mV
8.0
48
mV
mV
mV
dB
dB
-8.5
dB
ACF Voltage (VCC-Pin 25 Voltage)
VACF
Transmit Attenuator Gain(1.0kHz)
Tx Mode, Pin 3 = 250mVrms
Range, (Tx to Rx Mode)
Idle Mode, Pin 3 = 250Mvrms
TXO Sink Current (Tx mode)
TXO Source Current (Tx mode)
TXO Input Resistance
SPEAKER AMPLIFIER
Speaker Amp Gain
SKI Input Resistance
SKO Voltage
GTX
GTX
4.0
40
150
6.0
75
6.0
44
GTXI
-16.5
-13
ISINK
75
1.0
3.5
5.0
3.0
8.0
μA
mA
kΩ
33
15
2.4
34
22
3.0
35
37
3.6
dB
kΩ
Vdc
ISOURCE
RIN
GSPK
RIN
VO(SKO)
High
VSKOH
Low
VSKOL
SKO Voltage
Pin 19 = 20mVrms
Pin 19 =Cap couple to GND
Pin 19 = 0.1V, -100mA Load at
Pin 15
Pin 19=0.1V
+100mA Load at Pin 15
MICROPHONE AMPLIFIER
Pin 9 = 10mVrms,1KHz
Microphone Amp Gain
GMCI
Microphone Amp Input Resistance
RMCI
LOGAMPS
RLO
Pin 8 = VB+1.0V
Leakage Current
ILEAK
TLO
Pin 6 = VB+1.0V
Ratio of ITLI to IRLI - at 20A -to
Transmit-Receive Switching
ITH
Switch Tx-Rx Comparator)
Threshold
TRANSMIT DETECTOR
Idle Mode
XDC Voltage
VXDC
Tx Mode
CP2 Current Source
ICP2
Distortion
Rx Mode, RXI to SKO
RXD
Pin 27 = 10mVrms,1KHz
Tx Mode, MCI to TXO
TXD
Pin 9 = 5mVrms,1KHz
Note 1: V+=7.5V, CS =0.7V except where noted.
Note 2: Rx mode: Pin7=-100μA,Pin5=+100μA, except where noted.
Tx mode: Pin 5,13=-100A, pin 7=+100μA, Pin 11=0V.
Idle mode: Pin 5=-100μA, pin 7, 13=+100μA.
Note 3: Current into a pin designed as +, current out of a pin designed
Note 4: Voltage referred to pin 22, TA=25C.
UNISONIC TECHNOLOGIES CO., LTD
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5.5
32.5
6.5
Vdc
34
10
0.8
5.0
600
mV
35
16
dB
kΩ
2.0
2.0
μA
μA
1.2
0
4.0
10
1.5
2.0
13
Vdc
Vdc
μA
%
%
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QW-R108-006.E
MC34018
LINEAR INTEGRATED CIRCUIT
TEST CIRCUIT
TRANSMIT
OUTPUT
DC line input
0.068 F
4.7k
10
VB
MIC
9
0.1 F
2k
MCO
12k
10k
0.05
F
13
12
XDI
11
CP2
23
CP1
18
XDC
59k
16
CS
V+
Vcc
transmit
detector comp
VCC
regulator
2.6k
MCI
Receive input
1000 F
200k
47 F
47 F
4.7 F
100k

Vcc
5.4V
MIC AMP
VB
3.3k
5
VB
TLO
GND
VB
AGC
peak
limiter
Vcc
RTI
1.0 F
17
Vcc
RECEIVE/TRANSMIT
COMP
7
22
56k
Attenuator
control
TRANSMIT
LOG AMP
2.2M
1.0 F
33k
500
0.068 F
6
Vth
(36mV)
VB
TLI
47 F
20
transmit
attenuator
Speaker
amp
receive
attenuator
500
VB
regulator
4.7k
VB
RECEIVE
AMP
RLO
0.068 F
VB
8
VLC ACF
21
24
25
TXI
3
RTX RR
2
1
TXO
4
RXI
RRX
27
28
RXO
26
SKI
SKG
19
SKO
14
15
VB
4.7 F
Vcc
30k
18k
0.1 F
24k
2.2M
91k
20k
47 F
1.0 F
47 F
4.3k
0.1 F
0.01
F
0.05
F
25
Fig 1 Test circuit
BASIC LINE POWERED SPEAKERPHONE

S1
F
T
47k
F
470k
0.01
Vcc
TXI
13
4
5
MCO
XDI
TXO
TLI
F
0.1
1.0
11
25
17
16
18
7
27
CP1
ACF
AGC
V+
CS
RLI
RXI
9 MCI
2k
UTC MC34018
15 SKO
47
F
14 SKG
VB
Vcc
RTX
RR
RRX
RXO
SKI
CP2
XDC
TLO
RLO
GND
24
21
20
2
1
28
26
19
12
23
6
8
22
F
47
18k
4.7
F
4.7
F
2.2M
F
30k
F
24k
2.2M
1.0
91k
47
200k
F
4.3k
1.0
VB
Volume 20k
Control
0.05
F
VLC
0.01
F
Speaker
F
F
10
4.7
100k
0.068
mF
F
S2
3.3k
F
3.3k
0.068
4.7k
F
3
F
0.05
MIC
0.1
F
VB
47
VB
47k
F
15k
1000
F
2.2k
F
10
33k
47k
8.2k
0.01
F
8.2k
47k
F
470k
0.068
0.1
8.2k
4700pF 4700pF
6.8k
R
0.068
2.7k
22k
68k
470k
0.01 F
220k
Hook
Switch
F
0.05
0.01
4.7k
Fig 2
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QW-R108-006.E
MC34018
LINEAR INTEGRATED CIRCUIT
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
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