Datasheet KA8601C Datasheet (Samsung)

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

BNM : Back Noise Monitor

ORDERING INFORMATION

INTRODUCTION

The KA8601C is a monolithic integrated circuit for use in high perfor­mance speaker phone system.
The KA860lC consists of speaker phone and speech network. Speaker
phone includes attenuators, amplifiers, level detectors, attenuator
control, hybrid amplifiers, regulator and AGC circuit. Speech network
includes transmit amp, receive amp, voltage regulator for dialer, side
tone control, and line equalizer.

FEATURES

• Speaker Phone

- Low Operating Voltage (3.0 ~ 6.5V)

- High Attenuator Gain Range (52dB)

- Improved Sensitivity (Four-point Signal Sensing)

- Chip Disable for Active or Standby Operation

- Microphone Amp Gain set by External Components

• Speech Network

- Low Operating Voltage (1.5V : speech)

- Regulated Voltage for Dialer (Typically 3.3V)

- Transmit, Receive, Side Tone Gains set by
External Components

- Mute Input for DTMF Dialing

KA8601C 48-SDIP-600

BLOCK DIAGRAM

TX1

RX1

DTO­48

GND

44

RX1

PD RXDETI

43

42

ATT

ATT

RXO

RXI

DTI
47

46

45

DETO

41

DETO

40

TX1

DETI

39

MICO

38

MICIMTVC

36

37

35

48-SDIP-600

Device Package Operating Temperature

- 25°C ~ + 75°C

TX2

RX2

RX2

CT

DETI

34

33

DETO

32

DETO

31

TX2

DETI

30

PD TXVB

29

ATT

ATT

DD

TXI

TXO

V

28

27

26

25

hybrid

amp 1

SPEAKER PHONE PART

hybrid

amp 2

1

2

3

DTO+CDFI

RX

FILTER

4

4

FO

Attenuator

5

MT

BNM

DC level

shift

6

VI

SPEECH NET-

WORK PART

8

7

VL

LC

level

detector

1.7Vreg

9

VR

10

MICI-

11

MICI+

mic

amp

12

GND

mic

amp

ATTENUATOR
CONTROLLER

TX

13

MICO

14

TXI

amp2

TX

15

AGC

AGC

AGC

amp1

level

detector

REC

amp

16

17

RXO+NCNC

BNM

sidetone

amp

20

18

19

RXI

RXO-

21

SUM

RXO

TX

Attenuator

RX

22

ZB

amp

3.3Vreg

POWER

23

24

CC

V

MS

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

PIN CONFIGURATION

1

DTO+

2

CD

3

FI

4

FO

5

R4

6

V

I

7

VL

8

L

C

9

VR

10

MICI-

MICI+

GND

MICO

AGC

RXO+

RXO-

RXI

RXO

SUM

V

KA8601C

11

12

13

14

TXI

15

16
17

NC

18

NC

19

20

21

22

Z

B

23

MS

24

CC

48

47

46

45
44

43

42

41

40

39

38

37

36

35

34

33
32

31

30

29

28

27

26

25

Fig. 2

PIN DESCRIPTION

Pin No Symbol Description

1 DTO+ Output of the second hybrid amplifier.
2 CD Chip Disable. A logic low (<0.8V) sets normal operation.
3 FI Filter input.
4 FO Filter output.
5 MT Mute input. A logic “1” sets normal speech mode.
6 V

7 V
8 L

9 V

I

L

C

R

10 MICI- Inverting differential input to the mic amp.
11 MICI+ Non-inverting differential input to the mic amp.
12 GND Ground pin for the speech network.
13 MICO Mic amp output.
14 TXI Input to the TX amp from the Mic amp.
15 AGC Loop current sensing input.

A resistor connected from this pin to VSS sets the AC terminating impedance.
Power supply for the speech network. Supply voltage is derived from loop current.
TX amp output operates on this pin.
Resistor at this pin set the DC characteristics of the circuit.
A 1.7 volt regulated output which can be used to bias the mic.

DTO­DTI

ATT

RXO
RXI

ATT

GND
PD

RX

DETIRX1
DETO
DETOTX1
DETI

TX1

MICO
MICI
MT
V

C

CT
DETIRX2
DETO
DETO
DETI

TX2

PD

TX

V

B

TXI

ATT

TXO

ATT

V

DD

RX1

RX2

TX2

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

PIN DESCRIPTION (continued)

Pin No Symbol Description

16 RXO+ RX amp non-inverting differential output.
17 NC No connection.
18 NC No connection.
19 RXO- RX amp inverting differential output.
20 RXI Input to the RX amp.
21 RXO
22 Z

SUM

B

23 MS
24 V
25 V
26 TXO
27 TXI
28 V
29 PD

CC

DD

ATT

ATT

B

TX

30 DETITX2 Input to the TX level detector on the mike/speaker side.
31 DETOTX2 Output of the TX level detector on the mike/speaker side.
32 DETORX2 Output of the RX level detector on the mike/speaker side.
33 DETIRX2 Input to the RX level detector on the mike/speaker side.
34 C
35 V

T

C

36 MT
37 MICI Input and summing node of the mic amp.

38 MICO Output of the mic amp is set by external resistors.
39 DETTX1 Input to the TX level detector on the line side.
40 DETOTX1 Output of the TX level detector on the line side.
41 DETORX1 Output of the RX level detector on the line side.
42 DETIRX1 Input to the RX level detector on the line side.
43 PD

RX

44 GND Ground pin for the speaker phone part.
45 RXI
46 RXO

ATT

ATT

47 DTI Input and summing node of the mic amp.
48 DTO - Output of the first hybrid amplifier.

Summed output of the RX current amp.
Input to the RX current amp.
Mode select input. A logic “1” → pulse dialing, A logic “0” → tone (DTMF) dialing.
A supply voltage pin for the speaker phone part.
A regulated 3.3 volt output for an external dialer.
Output of the TX attenuator.
Input to the TX attenuator.
This voltage is a system AC ground, and biases the volume control. A filter cap is required.
An RC at this pin sets the time constant for the TX background monitor.

This pin sets the response time for the circuit to switch modes.
Volumn control input.
Mute input. A logic low (<0.8V) sets normal operation. A logic high (>2.0V) mutes the
mic amp.

A RC at this pin sets the time constant for the RX background monitor.

Input to the RX attenuator and dial tone detector.
Output of the RX attenuator.

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

ABSOLUTE MAXIMUM RATINGS

Characteristic Symbol Value Unit

Supply Voltage

Speaker

Phone

Voltage at V

C

Voltage at CD,MT
Voltage at TXI, RXI, HFI
Supply Voltage

Speech

Network

Supply Voltage for dialer
Voltage at MTS, MS
Current Through VL, L
Current into Z

B

C

Operating Temperature T
Storage Temperature T

ELECTRICAL CHARACTERISTICS (Ta = 25°C)

Characteristic Symbol Test Conditions Min Typ Max Unit

SPEECH NETWORK (Ta = 25°C, unless otherwise noted)

Line Voltage V

VR Voltage V

MF Operating Voltage

MF Operating Current (Max) I

MICO Bias Voltage V
TXI Bias Voltage V
MIC Amp Gain G
MIC Common Mode
Rejection Ratio
MIC Gain Reduction

TX Gain

TX Distortion THD

RX Gain

RX Distortion THD
Side Tone Gain G

L

R

V

DD (MF)

DD MF (MAX)IL

BIAS (MPO)IL

BIAS (TxTs)IL

V (MIC)IL

CMRR

(MIC)

∆G

V (MIC)

G

V (TX)

TXIL

G

V (RX)

RXIL

V (ST)

V

CC

V

I (VC)

V

I (CM)

V

I (TRH)

V

CC

V

DD

V

I (MS)

I

I (VL, LC)

I

I (ZB)

OPR

STG

- 1.0 ~ + 7.0

- 1.0 ~ VCC + 0.5

-1.0 ~ VCC + 1.0

- 0.5 ~ VCC + 0.5

- 1.0 ~ + 12

- 1.0 ~ + 6.0

- 1.0 ~ VDD + 0.5
130

3

- 25 ~ + 75

- 65 ~ + 150

V
V
V
V
V
V

V
mA
mA

°C
°C

Speech Mode IL = 30mA 3.0 3.9 4.7
Pulse Mode IL = 120mA 8 9.8 11.5
Tone Mode IL = 30mA 4.4 5.1 6.5
IL = 30mA Speech Mode 1.55 1.7 1.85 V

VL = 4.5V Tone Mode 3.0 3.3 3.8
Tone Mode IDD = 1.6mA 3.0 3.3 3.8

Speech Mode 0.5 1.1 2.0

= 30mA Pulse Mode 2 2.8 4

mA

Tone Mode 2 2.8 4

= 30mA Speech Mode 0.8 1.08 1.4 V
= 30mA Speech Mode 0.04 0.086 0.2 V
= 30mA Speech Mode 27 30 33 dB

-

30 64

-

dB
MT = 0V -10 -60 - dB

Speech Mode

IL = 30mA 30 34.8 60
IL = 80mA 28 31 34

dB

= 30mA Speech Mode - - 2 %

Speech Mode

IL = 30mA -15 -10.5 -2
IL = 80mA -17 -14 -10

dB

= 30mA Speech Mode - - 2 %

IL = 30mA Speech Mode - 10 15 dB

V

V

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

ELECTRICAL CHARACTERISTICS (Continued)

Characteristic Symbol Test Condition Min Typ Max Unit

Side Tone Rejection RST 20 25 - dB
MUTE Input Impedance Z
MUTE Input Low Voltage
MUTE Input High Voltage

MS Input Low Voltage
MS Input High Voltage

LC Level Shift

I (MUTE)

V

IL (MUTE)

V

IH (MUTE)

V

IL (MS)

V

IH (MS)

∆ V

LC

IL = 30mA Pulse Mode 2.1 2.9 3.5

SPEAKER PHONE (Ta = 25°C, VCC = 5.0V, unless otherwise noted)

Operating Current

Reference Voltage V

I

CC

REF

VCC = 6.5V

VCC = 3.5V - 1.3 ­VC = V

B

RX Attenuator Gain G

ATT (RX)

VCC = 3.5V, VC = V

VCC = 2.8V, VC = V
RX Attenuator Gain Change
RX Attenuator AGC Gain Change
RX Attenuator Gain (Idle Mode) G
RX Attenuator Gain Range G
RX Volume Control Range G
RX DC Output Voltage V
RX DC Output Voltage Change
RX DC Output High Voltage V
RX DC Output Low Voltage
(with respect to VB)

∆G

∆G

ATT AGC (RX)

ATT RX (IM)

V CTL (RX)

∆V

V

ATT (RX)

ATT (RX)

O (RX)

OH (RX)

OL (RX)

RX Mode Distortion THD

O (RX)

VCC = 3.5V, to 5.0V -0.5 0 +0.5 dB

VCC = 2.8V, to 5.0V - -25 -15 dB

VC = V

B

VC = VB (RX to TX Mode) 49 52 54 dB

VC = 0.1V

B

RX to TX Mode -

V

= 3.5V 3.7 - - V

RXI

V

= 1V

RXI

RX

RX Mode - +240 ­CT Voltage (with respect to VB) V

CT

Idle Mode - 0 - mV

TX Mode - -240 ­Dial Tone Detector Threshold V
TX Attenuator Gain G
TX Attenuator Gain Range G
TX Output DC Voltage V
TX Output DC Voltage Change

TH (DET)

ATT (TX)

ATT (TX)

∆V

O (TX)

O (TX)

VC = VB, V

RXI

Speech Mode 2.1 2.9 3.5

Tone Mode 3.4 4.3 5.2

CD = 0.8V - 5.5 8.0
CD = 2V - 0.6 0.8

IL = 1.0mA 1.5 1.7 1.9

B

B

= 3.0V 10 15 20 mV

- 60 -

-

V

DD

1.0

-

-0.3

-

2.0

0.8

-

1.8 2.1 2.4

4.0 6.0 8.0

4.0 6.0 8.0 dB

- -19 -11

-22 -20 -17 dB

27 35 - dB

- V

- V

B

± 10 ±150

-

-1.5 -1.0 V

- 0.5 3 %

4.0 6.0 8.0 dB
49 52 54 dB

- V

-

± 30 ±150

- V

B

KΩ

V

V

mA

V

mV

mV

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

ELECTRICAL CHARACTERISTICS (Continued)

Characteristic Symbol Test Conditions Min Typ Max Unit

TX Output High Voltage V
TX Output Low Voltage V

OH (TX)

OL (TX)

TX Mode Distortion THD
MIC Voltage Gain G
MIC Output Offset Voltage V
MIC Output High Voltage V
MIC Output Low Voltage V
MIC Input Bias Current I
Muting (Gain) G

V (MIC)

OO (MIC)

OH (MIC)

OL (MIC)

BIAS (MIC)

V (MUTE)

MIC Amp Distortion THD
MUTE Input High Voltage V
MUTE Input Low Voltage V
Open Loop Gain (Hybrid Amp) G
DTO-Output High Voltage V
DTO-Output Low Voltage V
DTO+Output High Voltage V
DTO+Output Low Voltage V

IH (MUTE)

IL (MUTE)

V (HA)

OH (DTO -)

OL (DTO -)

OH (DTO +)

OL (DTO +)

DTO Distortion THD
Filter Offset Voltage V
Filter Input Bias Current V

IO (F)

BIAS (F)

DTO

TX

MIC

V

= 3.5V 3.7 - - V

TXI

V

= 1.0V - 0.5 1 V

TXI

- 0.8 3 %

70 80 - dB

-50 0 +50 mV

V

= 1.0V 3.7 - - V

MIC

V

= 3.0V - - 200 mV

MIC

- -40 - nA

VMT = 2V, f = 1KHz -55 - - dB

- 0.15 - %

0.3KHz ≤ f ≤ 10KHz

2.0 - V

CC

0 - 0.8 V

60 80 - dB

3.7 - - V

- - 250 mV
IO = -5mA 3.7 - - V
IO = 5mA - - 250 mV
IO = -5mA - 0.3 - %
IO = 5mA -22 -90 0 mV

0 -50 - mA

V

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

APPLICATION INFORMATION
FUNCTION DESCRIPTION

SPEECH NETWORK

1. MICROPHONE AMPLIFIER

This microphone amplifier is equipped with a fixed gain (30dB). Its basic configuration is shown in figure 3.

MICI+

MIC-

20K 20K

Fig .3

This amplifier has a mute function. If a mute signal from the dialer is inputted when the speech network is in the mute
mode, the microphone amplifier will be muted.

2. VOLTAGE REGULATOR (DIALER INTERFERENCE)

This voltage regulator has a minimum output voltage of 3.1 volts. When the dialer is not in motion, its minimum current
is 1.0mA, where as when the dialer is moving the minimum current is 2.2mA.

3. VOLTAGE REFERENCE

Generally when in the voltage reference mode, the microphone's bias voltage is used, but when in the TXl
DC bias voltage is used. The output voltage of the voltage reference is a minimum of 1.6 volts.

SPEAKER PHONE

1. MICROPHONE AMPLIFIER

This device amplifies outside microphone signals, which are inputted while in the inverting mode. As it alters elements,
the microphone amplifier allows for them to be modulated. Its open loop gain is 80dB, while the band width is typically

1.0KHz. It has a mute function, and when operating in the mute mode at least 2.0V, the microphone amplifier gain
is reduced to around 40dB. If the mute mode is not used, it must connected with the ground.

+

-

30dB

Rf

MT

MICO

ATT

mode,

MIC

Fig. 4

Ri

Bias Voltage

-

+

MICO

MT

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

2. VOLUME CONTROL

The volume control can only be applied in the receive mode. If the voltage of the VC mode is the same as the VB, the
receive attenuator gain is maximized and the transmit gain is minimized. At the same time, if the VC mode voltage is
less than the VB, the receive attenuator gain is reduced.

V

B

V

KA8601C

Fig. 5

3. VOICE DETECTION FUNCTION

The voice detection function compares the microphone amplifier output level with the outside audio amplifier level
and the transmit attenuator output level with the receive attenuator input level, after which they are inputted into the
control box. The block diagram of the voice detection function is as follows:

C

VOLUME

DETIRX1

DETORX1

A1

Log Amp

PD

Comparator

RX

Background
Noise Monitor

PD

TX

Comparator

DETOTX1

A3

Log Amp

DETI

TX

1

C1 C2

DETITX1

Log Amp

A2

DETOTX1

CO1 CO2

Attenuator Control Box

CO4CO3

DETOTX1

Log Amp

A4

DETI

1

RX

Fig. 6

It is useful to use a background noise monitor when high background noise occurs. When the input signals to the
background noise monitor are increased, voltage for the PDRX (PDTX) mode is stably increased. The increase time
is determined by 100KΩ and 47µF.

4. ATTENUATOR CONTROL BOX

In figure 6, each signal coming into the log amplifier is amplified and then inputted into the comparator (C1, C2). The
comparator compares the amplified signal levels, after which they are inputted into the attenuator control box. The
attenuator control box processes these signals (CO1, CO2, CO3, CO4) as logic signals, and which are put into one
of the following modes:

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

1. Receive Mode

2. Transmit Mode

3. Slow Idle Mode

4. Fast Idle Mode
Which of the above modes is to be determined depending on the following conditions:

1) Receive Mode

DETOTX1 < DETORX1, DETOTX2 < DETORX2, PDTX, X, PDRX : 1

2) Transmit Mode

DETOTX1 > DETORX1, DETOTX2 > DETORX2, PDTX : 1, PDRX : X

3) Slow Idle Mode

DETOTX1 > DETORX1, DETOTX2 > DETORX2, PDTX : 0, PDRX : X
DETOTX1 < DETORX1, DETOTX2 < DETORX2, PDTX : 0, PDRX : X
DETOTX1 < DETORX1, DETOTX2 > DETORX2, PDTX : 0, PDRX : X
DETOTX1 > DETORX1, DETOTX2 < DETORX2, PDTX : 0, PDRX : X

4) Fast Idle Mode

DETOTX1 > DETORX1, DETOTX2 < DETORX2, PDTX : 0, PDRX : 0
DETOTX1 < DETORX1, DETOTX2 > DETORX2, PDTX : Y, PDRX : Y
* "<" and ">" refer to voltage level : "X" refers to "It doesn't matter : "Y" is not zero

5. SWITCHING TIME

The switching time of the speaker phone is determined by the CT and RT of the outside elements.

1. Idle Mode → RX or TX Mode
ST = 4,000 X C

2. TX or RX Mode → Fast Idle Mode
ST = 2,000 X C

3. TX or RX Mode → Slow Idle Mode
ST = RT X C

* CT, RT refer to the capacitor and resistor between Pin 34 and VCC.

T

T

T

KA8601C SPEAKER PHONE WITH SPEECH NETWORK

APPLICATION CIRCUIT