njw1128 - njr. · pdf filenjw1128 – 1 – ver.2.2 voice switched speakerphone...

NJW1128

– 1 –

Ver.2.2

Voice Switched Speakerphone Circuit with Speaker Amplifier

GENERAL DESCRIPTION PACKAGE OUTLINE

The NJW1128 is a Voice Switched Speakerphone Circuit. It includes all of functions

processing a high quality hands–free speakerphone system, such as the necessary amplifiers ( Mic , Receive ,Line, Speaker ), attenuators, level detectors functions.

The NJW1128 is controllable independently power-down of the speaker amplifier and the entire IC excluding the speaker amplifier. All external capacitors are sufficient small so that ceramic capacitors are applied.

APPLICATION

Video Door Phone Conference System Wireless Application Security System

FEATURES

Operating voltage range 3.9 to 5.5V Attenuator gain range between Transmit and Receive 52dB Speaker amplifier Microphone amplifier with mute function Force to Receive, Transmit, or Idle modes Mode –watching monitor Background noise monitor for each path 4-point signal sensing Chip disable Pin powers down the entire IC excluding

the speaker amplifier Speaker switch Pin power down the speaker amplifier Microphone and Receive Amplifiers pinned out for flexibility Package Outline LQFP48-R3

BLOCK DIAGRAM

NJW1128FR3

BIAS

Tx Atten uato r

AttenuatorControl

LevelDetector

BackgroundNoi seMon itor

Monitor

Speaker

Microphone

-1

Rx Attenuator-1

L evelDetector

Backgrou ndNo iseM onitor

V+

V+

Speaker Ampl ifier

L ine Amplifier

V +

Line Out

VLC

V+

M ICIN MICOUT TLI2 TLI1 TXO LII LiO- LiO+

V+

RTSW

CPR

TLO1

RLO1

GND

RLI2RXOSPISPO-SPO+

SPSW

CD

VREF

CPT

RLO2

TLO2

M UT

CT

VREF

C5 100n

C6 100n

C41u

C20 1

R1051k

R115.1k

C14100n

R125.1k

C8100n

R43k

R5300k

C9100n

R65.1k

R75.1k

C10100n

R85.1k

R951k

R135.1k

C13100n

C19100n

C20 100n

C21 1

C7 1

C121

C11100n

C2 1

C3 1

R2300k

R3300k

M icAmplifier

Receiv eAmpli fier

1.2A

CfL

CfS

V+ :Recive GND :Trensmit Open :idle

MUT V+ :MUTE GND :ACTIVE

SPSW V+ :ACTIVE GND :Power Down

V RE F

VREF

V RE F

RVL C

V+

R3300k

CD V+ :ACTIVE GND :Power Down

C1 1

SPGND

SPV+

C221SPV+

FIFORLI1

Recive In

C15100n

R145.1k

R155. 1k

C16100n

CfR

NJW1128

– 2 –

ABSOLUTE MAXIMUM RATING (Ta=25C) PARAMETER SYMBOL RATING UNIT

Power Supply Voltage V+ 7 V

Power Dissipation PD 1,330(Note1) mW

Operating Temperature Range Topr -40 ~ +85 C

Storage Temperature Range Tstg -40 ~ +125 C

Maximum Input Voltage VIMAX 0 ~ V+ (Note2) V (Note1) EIA/JEDEC STANDARD Test board (76.2x114.3x1.6mm, 2layer, FR-4) mounting OPERATING VOLTAGE

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Operating Voltage V+ - 3.9 5.0 5.5 V

ELECTRICAL CHARACTERISTICS (Ta=25C,V+=5V,MUT=CD=SPSW= ACTIVE ,RTSW=OPEN, RVLC=0, MIC Amplifier Gv=0dB, Receive Amplifier Gv=0dB) ●Power Supply

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT

Operating Current 1 ICC1 RX-mode (Receive) 2.0 3.5 6.0 mA

Operating Current 2 ICC2 TX-mode (Transmit) 2.0 3.5 6.0 mA

Operating Current 3 ICC3 Idle-mode (Standby) 2.0 3.5 6.0 mA

Operating Current 4 ICC4 Idle-mode (Standby) , SPSW=PD

1.0 2.5 4.0 mA

Operating Current 5 ICC5 CD=PD,SPSW=PD 0.5 1 1.5 mA

Reference Voltage VREF Idle-mode (Standby) 2.2 2.5 2.8 V

●Receive Attenuator(RxIN=200Vrms,Receive Amplifier Gv=0dB)


Receive Attenuator Gain 1 GR1 RX-mode (Receive) 3.0 6.0 9.0 dB

Receive Attenuator Gain 2 GR2 TX-mode (Transmit) -50 -46 -42 dB

Receive Attenuator Gain 3 GR3 Idle-mode (Standby), CRT=CPR=V+

-23 -20 -17 dB

Range R to T mode dGR RX-mode – TX-mode 47 52 57 dB

Dynamic DC offset GRDC RX-mode – TX-mode (DC) -50 - 50 mV

Volume control range GRVR RX-mode,RVLC=0-100k 35 45 55 dB

●Transmit Attenuator (TxIN=200Vrms,Mic.amplifier Gv=0dB)


Transmit Attenuator Gain 1 GT1 TX-mode (Transmit) 3.0 6.0 9.0 dB

Transmit Attenuator Gain 2 GT2 RX-mode (Receive) -50 -46 -42 dB

Transmit Attenuator Gain 3 GT3 Idle-mode, (Standby) CRT=CPR=V+

-23 -20 -17 dB

Range R to T mode dGT TX-mode – RX-mode 47 52 57 dB

Dynamic DC offset GTDC TX-mode – RX-mode (DC) -50 - 50 mV

NJW1128

– 3 –

●MIC Amplifier(TxIN=1mVrms,Gv=40dB,RL=5.1k)


Output Offset Voltage VMOS R5=300k, VMOS=VMCI-VMCO -50 0.0 50 mV

Input Bias Current IMBIAS - 30 - nA

Voltage Gain 1 GVM1 f=1kHz - 40 - dB

Voltage Gain 2 GVM2 f=20kHz - 36 - dB

Maximum Output Voltage VMMAX THD=1% 1.0 - - Vrms

Maximum Attenuation GMMUTE MUT=MUTE -70 -73 - dB

●Receive Amplifier (RxIN=1mVrms,Gv=40dB,RL=5.1k)


Output Offset Voltage VROS R14=300k, VFOS=VFI-VFO -50 0.0 50 mV

Input Bias Current IRBIAS - 30 - nA

Voltage Gain 1 GVR1 f=1kHz - 40 - dB

Voltage Gain 2 GVR2 f=20kHz - 36 - dB

Maximum Output Voltage VRMAX THD=1% 1.0 - - Vrms

●Line Amplifier (LINEIN=50mVrms, GV=26dB,RL=1.2k)

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Output Offset Voltage VLOS R9=51k -50 0.0 50 mV

Input Bias Current IRBIAS - 30 - nA

Voltage Gain 1 GvL1 f=1kHz - 26 - nA

Voltage Gain 2 GvL2 f=20kHz - 25 - nA

Gain Bandwidth GLBW RL=600,LIO - 1.5 - MHz

Closed Loop Gain GLC RL=1.2k,LIO- to LIO+ -0.5 0 0.5 dB

Maximum Output Voltage VLMAX RL=1.2k,THD=1% 2.0 - - Vrms Total Harmonic Distortion THDLN GV=20dB, RL=1.2 - - 0.5 %

●Speaker Amplifier (SPIN=50mVrms, GV=26dB,RL=32)

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Output Offset Voltage VSPOS R10=51k -50 0.0 50 mV

Input Bias Current ISBIAS - 0 - nA

Voltage Gain 1 GVSP1 f=1kHz - 26 - dB Voltage Gain 2 GVSP2 f=20kHz - 24 - dB Voltage Gain 3 GVSP3 f=1kHz, GVSP=6dB,RL=8 - 6 - dB

Voltage Gain 4 GVSO4 f=20kHz, GVSP=6dB,RL=8 - 4 - dB

Closed Loop Gain GLC SPO- to SPO+ -0.6 0 0.6 dB

Maximum Output Power PoMAX1 f=1kHz, RL=32,THD=3% 200 300 - mW PoMAX2 f=1kHz, RL=8,THD=3% 300 500 - mW

Total Harmonic Distortion THDSP1

VIN=50mVrms,f=1KHz, RL=32,GVD=26dB

- 1.0 %

THDSP2 VIN=500mVrms,f=1KHz, RL=8,GVD=6dB

- - 1.0 %

NJW1128

– 4 –

●MONITOR TERMINAL (MON)


RX-mode Rx - V+-0.6 - V+ V

TX-mode Tx - GND - 0.6 V

Idle-mode Idle No Signal 2.4 2.5 2.6 V

Maximum Output Current IMON Rx-mode / Tx-mode - 0.9 - mA

LOGIC CONTROL ●SW CHARACTERISTICS 1 (CD,MUT,SPSW)


Low Level Input Voltage VIL1 - - - 0.3 V

High Level Input Voltage VIH1 - 1.5 - - V ●SW CHARACTERISTICS 2 (RTSW)


Low Level Input Voltage VIL2 - - - 0.3 V

High Level Input Voltage VIH2 - V+-0.3 - - V FUNCTION ●CD

INPUT VOLTAGE STATUS OPERATION

VIH ACTIVE NJW1128 is active.

VIL PD NJW1128 is shutdown except Speaker Amplifier. ●MUT


VIH MUTE The microphone input is mute.

VIL ACTIVE The microphone input is active. ●SPSW


VIH ACTIVE The Speaker Amplifier is Active.

VIL PD The Speaker Amplifier is Shutdown. ●RTSW


VIH Receive Force to Receive mode.

OPEN AUTO Receive mode and Transmit mode are automatically switched.

VIL Transmit Force to Transmit mode. ●RVLC (34pin)

IMPEDANCE STATUS OPERATION

0 VolMAM The Receive attenuator Volume is maximum.

100k VolMIN The Receive attenuator Volume is minimum.

NJW1128

– 5 –

APPLICATION CIRCUIT

C7220n

C81u

C10100n

R65.1k

R851k

C13100n

R95.1k

SP Out+

C51u

C281u

C27220n

R2051k

C22100n

R195.1k

R225.1k

C25100n

R10510

R125.1k

R18510

R155.1k

ReceiveIn

C191n

V+

R1300k

H:MUTEL:ACTIVE

H:ActiveL: PowerDown

MIC IN

H:ReciveL:TrensmitO:Auto

Rx-Mode :HTx-Mode :LIdle :HI-Z

1

2

3

4

5

6

7

8

9

10

11

12

13 14 15 16

48 43 42 41 40 39 38 37

36

35

34

33

32

31

30

29

RLI1

LIO-

LII

TXO

TLI1

RXO

SPI

NC

SPO+V+V+ V+ V+ NC

NC

NC

NC

LIO+

MCO

CT

NC

MCI FI

FO

VLC

NC

NC

TLO1RLO2

17 18 19 20 21 22

28

27

26

25

2423

SPO-GND SPO-

H:ACTIVEL:PowerDown

47 46 45 44

GND

TLO2 CPT SPSW CDMUT GND V+ MON RTSW CPRVREF RLO1

Line Out＋

C15100n

TLI2

RLI2

R135.1k

C161n

C141u

SPO+

V+

C1710u

NJW1128C211u

R165.1k

C26220n

C6220n

V+

C11u

C21u

C20100n

C291u

V+

C31u

R2300k

V+

C41u

R3300k

C12100p

TR1

V+

LED1R242.2k

R2351k

C301u

MON

SP Out－

Line Out－

TX OUT RXOUT

C23100p

++ C1810u

V+Open

SW1

SW2

SW3

SW4

VR1100k

2

13

LINE IN SP IN

C11

V+

+

C9R4

R5R70

R110

*R14

*R170

C24

R210

MIC OUT FO

*R14 : Dummy Load

*R11 : Jumper *R17 : Jumper

*R7 : Jumper

*R21 : Jumper

NJW1128

– 6 –

TYPICAL CHARACTERISTICS

Supply Current vs Supply VoltageNo Signal , Supply Current 1

0

1

2

3

4

5

6

0 1 2 3 4 5 6 7 8

Supply Voltage [V]

Supp

ly C

urre

nt [m

A]

-40degC

+25degC

+85degC


0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0 1 2 3 4 5 6 7 8

Supply Voltage [V]

Supp

ly C

urre

nt [m

A]

-40degC

+25degC

+85degC


0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0 1 2 3 4 5 6 7 8

Supply Voltage [V]

Supp

ly C

urre

nt [m

A]

-40degC

+25degC

+85degC

Supply Current vs TemperatureV+ =5.0V , No Signal

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Supp

ly C

urre

nt [m

A]

Supply Current 1

Supply Current 4

Supply Current 5

RxAtt Gain vs TemperatureV+ =5.0V , RecieveAmp : 0dB , RL=5.1k

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Gai

n [d

B]

Idle-Mode

RX-Mode

Tx-Mode

RxAtt Gain vs TemperatureV+ =5.0V , Rx-Mode , RecieveAmp : 0dB , RL=5.1k

30

32

34

36

38

40

42

44

46

48

50

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Vol

ume

Con

trol R

ange

[dB]

NJW1128

– 7 –


TxAtt Gain vs TemperatureV+ = 5.0V , MicAmp : 0dB , RL=5.1k

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

5

10

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Gai

n [d

B]

Idle-Mode

TX-Mode

RX-Mode

RecieveAmp Maximum Output Voltage vs TemperatureV+ = 5.0V , f = 1kHz Rf = 300k , Gv=40dB , RL=5.1k , THD+N = 1% , BW=400Hz-30kHz

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Max

imum

Out

put V

olta

ge [V

rms]

MicAmp Maximum Output Voltage vs TemperatureV+ =5.0V , f = 1kHz , Rf = 300k , Gv=40dB , RL=5.1k, THD+N = 1% , BW=400Hz-30kHz

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Max

imum

Out

put V

olta

ge [V

rms]

MicAmp Mute Range vs TemperatureV+ =5.0V , Rf = 300k , Gv=40dB , RL=5.1k , A-Weighting

70

71

72

73

74

75

76

77

78

79

80

-50 -30 -10 10 30 50 70 90 110 130 150

LineAmp THD vs TemperatureV+ =5.0V , f = 1kHz , Rf = 51k , Gv=26dB , Vin = 50mVrms , RL=1.2k , BW=400Hz-30kHz

0

0.05

0.1

0.15

0.2

0.25

0.3

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

THD

+N [%

]

LineAmp Maximum Output Voltage vs TemperatureV+ =5.0V , f = 1kHz , Rf = 51k , Gv=26dB , RL=1.2k , THD+N = 1% , BW=400Hz-30kHz

2

2.1

2.2

2.3

2.4

2.5

2.6

2.7

2.8

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Max

imum

Out

put V

olta

ge [V

rms]

NJW1128

– 8 –


Speaker Amp Maximum Output Pow er vs TemperatureV+ =5.0V , f = 1kHz , THD+N = 3% , BW=400Hz-30kHz

0

100

200

300

400

500

600

700

800

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

Max

imum

Oup

ut P

ower

[mW

]

8 / 6dB

32 / 26dB

Speaker Amp THD vs TemperatureV+ =5.0V , f = 1kHz , BW=400Hz-30kHz

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

-50 -30 -10 10 30 50 70 90 110 130 150

Temperature [degC]

THD

+N [%

]

8 / 6dB

32 / 26dB

Receive Amp THD+N vs Input VoltageV+ = 5.0V , f = 1kHz Rf = 3k, Ri=3k, Ci = 1F , Gv=0dB , RL=5.1k , BW=400Hz-30kHz

0.001

0.01

0.1

1

10

0.01 0.1 1 10

Input Voltage [%]

THD

+N [%

]

-40degC

+25degC

+85degC

Receive Amp THD+N vs Input VoltageV+ = 5.0V , f = 1kHz Rf = 300k, Ri=3k , Ci = 1F , Gv=40dB , RL=5.1k ,

BW=400Hz-30kHz

0.1

1

10

0.0001 0.001 0.01 0.1

Input Voltage [Vrms]

THD

+N [%

]

-40degC

+25degC

+85degC

Mic Amp THD+N vs Input Voltagef = 1kHz Rf = 3kohm , Ri=3kohm , Ci = 1uF , Gv=0dB , RL=5.1kohm ,BW=400Hz-30kHz

Ta = -40degC

0.001

0.01

0.1

1

10

0.01 0.1 1 10

THD+N [Vrms]

THD

+N [%

]

-40degC

+25degC

+85degC

Mic Amp THD+N vs Input VoltageV+ = 5.0V , f = 1kHz Rf = 300k , Ri=3k , Ci = 1F , Gv=40dB , RL=5.1k ,

BW=400Hz-30kHz

0.1

1

10

0.0001 0.001 0.01 0.1


THD

+N [%

]

-40degC

+25degC

+85degC

NJW1128

– 9 –


Line Amp THD+N vs Input Voltage

f = 1kHz Rf = 51kohm , Ri=5.1kohm , Ci = 1uF , Gv=26dB , RL=1.2kohm ,BW=400Hz-30kHz

Ta = -40degC

0.1

1

10

0.001 0.01 0.1 1


THD

+N [%

]

-40degC

+25degC

+85degC

Speaker Amp THD+N vs Output Pow erV+ = 5.0V , f = 1kHz Rf = 51k , Ri=5.1k , Ci = 1F , Gv=26dB , RL=32 ,BW=400Hz-30kHz

0.1

1

10

0.001 0.01 0.1 1

Output Pow er [Wrms]

THD

+N [%

]

-40 degC

+25 degC

+85 degC

Speaker Amp THD+N vs Output Pow erV+ = 5.0V , f = 1kHz Rf = 5.1k , Ri=5.1k , Ci = 1F , Gv=26dB , RL=8 ,BW=400Hz-30kHz

0.1

1

10

0.001 0.01 0.1 1

Output Pow er [Wrms]

THD

+N [%

]

-40degC

+25degC

+85degC

Receive Amp Maximum Output Voltage vs Load ImpedanceV+ = 5.0V ,Rf = 300k , Ta=25degC

0

1

2

3

4

5

6

100 1000 10000 100000

Load Impedance []

Max

imum

Out

put V

olta

ge [V

]

Mic Amp Maximum Output Voltage vs Load ImpedanceV+ = 5.0V ,Rf = 300k , Ta=25degC

0

1

2

3

4

5

6

100 1000 10000 100000

Load Impedance []

Max

imum

Out

put V

olta

ge [V

]

NJW1128

– 10 –


Rx Att Maximum Output Voltage vs Load ImpedanceV+=5.0V , Ta=25degC

0

1

2

3

4

5

6

100 1000 10000 100000

Load Impedance []

Max

imum

Out

put V

olta

ge [V

]

Tx Att Maximum Output Voltage vs Load ImpedanceV+=5.0V , Ta=25degC

0

1

2

3

4

5

6

100 1000 10000 100000

Load Impedance []

Max

imum

Out

put V

olta

ge [V

]

Line Amp Maximum Output Voltage vs Load ImpedanceV+ = 5.0V ,Rf = 51k , Ta=25degC

0

1

2

3

4

5

6

100 1000 10000 100000

Load Impedance []

Max

imum

Out

put V

olta

ge (L

IO+

to L

IO-)

[V]

Monitor out Maximum Output Voltage vs Load ImpedanceV+=5.0V , Ta=25degC

0

1

2

3

4

5

6

100 1000 10000 100000

Load Impedance []

Max

imum

Out

put V

olta

ge [V

]

NJW1128

– 11 –


Pd vs Output PowerV+=5.0V , f=1kHz , Gv=6dB , BW=400Hz-30kHz , Ta=25degC

0

100

200

300

400

500

600

700

0 100 200 300 400 500 600 700

Output Power [mW]

Pd

[mW

]

THD=1%THD=3%

RecieveAmp Voltage Gain vs FrequencyVin = 100mVrms , Rf = 3k , Ri = 3k , Ci = 1F , Gv=0dB , RL=5.1k

-10

-8

-6

-4

-2

0

2

10 100 1000 10000 100000

Frequency [Hz]

Gai

n [d

B]

V+ =3.9V to 5.5VTa = -40degC to +85degC

RecieveAmp Voltage Gain vs FrequencyVin = 1mVrms , Rf = 300k , Ri = 3k , Ci = 1F , Gv=40dB , RL=5.1k

10

15

20

25

30

35

40

45

10 100 1000 10000 100000

Frequency [Hz]

Gai

n [d

B]


Mic Amp Voltage Gain vs FrequencyVin = 1mVrms , Rf = 300k , Ri = 3k , Ci = 1F , Gv=40dB , RL=5.1k

10

15

20

25

30

35

40

45

10 100 1000 10000 100000

Frequency [Hz]

Gai

n [d

B]


Mic Amp Voltage Gain vs FrequencyVin = 100mVrms , Rf = 3k, Ri = 3k , Ci = 1F , Gv=0dB , RL=5.1k

-10

-8

-6

-4

-2

0

2

10 100 1000 10000 100000

Frequency [Hz]

Gai

n [d

B]


NJW1128

– 12 –


Line Amp Voltage Gain vs FrequencyVin = 50mVrms , Rf = 51k , Ri = 5.1k , Ci = 1F , Gv=26dB , RL=1.2k

12

14

16

18

20

22

24

26

28

10 100 1000 10000 100000

Frequency [Hz]

Gai

n [d

B]


Speaker Amp Voltage Gain vs FrequencyVin = 50mVrms , Rf = 51k , Ri = 5.1k , Ci = 1F , Gv=26dB , RL=32

12

14

16

18

20

22

24

26

28

10 100 1000 10000 100000

Frequency [Hz]

Volta

ge G

ain

[dB]

V+ =3.7V , 5,0V , 5.5VTa = -40 , +25 , +85 degC

Speaker Amp Voltage Gain vs FrequencyVin = 500mVrms , Rf = 5.1k , Ri = 5.1k , Ci = 1F , Gv=6dB , RL=8

-10

-8

-6

-4

-2

0

2

4

6

8

10

10 100 1000 10000 100000

Frequency [Hz]

Gai

n [d

B] V+ =3.9V to 5.5VTa = -40degC to +85degC

Supply Current vs CD Pin VoltageV+ = 5.0V , SPSW = PD , RTSW = Open , no Signal

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5

CD Pin Voltage [V]

Supp

ly C

urre

nt [m

A]

+85 degC

+25 degC

-40 degC

Supply Current vs SPSW Pin VoltageV+ = 5.0V , CD = Active , RTSW = Open , no Signal

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0 0.5 1 1.5 2 2.5

SPSW Pin Voltage [Hz]

Supp

ly C

urre

nt [m

A]

+85 degC

+25 degC

-40 degC

NJW1128

– 13 –


Mic Amp Mute attenuate Range vs MUT Pin VoltageV+ = 5.0V , Vin = 1mVrms , Rf = 300kohm , Ri = 3kohm , Ci = 1uF , Gv=40dB , RL=5.1kohm

A-Weighting

-80

-70

-60

-50

-40

-30

-20

-10

0

10

0 0.5 1 1.5 2 2.5

MUT Pin Voltage [V]

Supp

ly C

urre

nt [m

A]

+85 degC

+25 degC

-40 degC

TX , RX attenuator Gain vs RTSW Pin Voltage

V+ = 5.0V , f = 1kHz , Vin = 200mVrms

-50

-40

-30

-20

-10

0

10

20

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

RTSW Voltage [V]

Gain [dB]

TX Att.

RX Att.

+85degC

+25degC-40degC

+85degC

+25degC-40degC

TX-Mode RX-ModeAuto(Idle)-Mode

RX Att.

TX Att.

NJW1128

– 14 –

■APPLICATION NOTES ■GENERAL DESCRIPTION

The NJW1128 is a Voice Switched Speakerphone Circuit. The NJW1128 includes all of functions processing a high quality hands–free speakerphone system, such as the necessary amplifiers ( Microphone amplifier , Receive amplifier, Line amplifier ,and speaker Amplifier), attenuators, level detectors .

The NJW1124 detects a signal to judges which path is talking. After that, the one side path is active, another path is attenuated. This is half-duplex system. Appropriate operating keeps closed loop gain less than 0dB, and that prevents acoustic coupling.

All external capacitors are sufficient small so that ceramic capacitors are applied. The resister and capacitor values in Fig.0.1 below are references. For correct operating, check in

actual condition as possible as you can. And adjust the levels input each detectors. On this application notes, Base unit is defined as the unit included the NJW1128.

The resistance and capacitor value above is just one example. Certain Half-duplex operation are not guaranteed. Best value depends on your microphone, speaker, and chassis. Understand NJW1128 operation and select appropriate value.

BIAS

Tx Attenuator

AttenuatorControl

LevelDetector

BackgroundNoiseMonitor

Monitor

Speaker

Microphone

-1

Rx Attenuator-1

LevelDetector


V+

V+

Speaker Amplifier

Line Amplifier

V+

Line Out

VLC

V+

MICIN MICOUT TLI2 TLI1 TXO LII LiO- LiO+

V+

RTSW

CPR

TLO1

RLO1

GND

RLI2RXOSPISPO-SPO+

SPSW

CD

VREF

CPT

RLO2

TLO2

MUT

CT

VREF

C5 100n

C6 100n

C41u

C20 1

R1551k

R165.1k

C21100n

R185.1k

C10100n

R63k

R8300k

C13100n

R95.1k

R105.1k

C14100n

R125.1k

R1351k

R195.1k

C20100n

C27100n

C26 100n

C38 1

C8 1

C1 1

C15100n

C2 1

C3 1

R2300k

R3300k

MicAmplifier

ReceiveAmplifier

1.3A

CfL

CfS

V+ :R ecive GND :Trensmit Open :idle



VREF

VREF

VREF

RVLC

(VR1)

V+

R1300k

CD V+ :ACTIVE GND :Power Down

C1 1

GND(SP)

SPV+(SP)

C17,181V+(SP)

FIFORLI1

Recive In

(4pins)

C22100n

R205.1k

R225.1k

C25100n

(2pins)

Fig.0.1 NJW1128 Block diagram

NJW1128

– 15 –

<Evaluation-Board Circuit>

C7330n

C81u

C10100n

R65.6k

R856k

C13100n

R933k

SP Out+

C51u

C281u

C27330n

R2056k

C22100n

R1933k

R225.6k

C25100n

R103.3k

R1251k

R183.3k

R1551k

ReceiveIn

V+

R1300k

H:MUTEL:ACTIVE

H:ActiveL: PowerDown

MIC IN

H:ReciveL:TrensmitO:Auto

Rx-Mode :HTx-Mode :LIdle :HI-Z

1

2

3

4

5

6

7

8

9

10

11

12

13 14 15 16

48 43 42 41 40 39 38 37

36

35

34

33

32

31

30

29

RLI1

LIO-

LII

TXO

TLI1

RXO

SPI

NC

SPO+V+V+ V+ V+ NC

NC

NC

NC

LIO+

MCO

CT

NC

MCI FI

FO

VLC

NC

NC

TLO1RLO2

17 18 19 20 21 22

28

27

26

25

2423

SPO-GND SPO-

H:ACTIVEL:PowerDown

47 46 45 44

GND

TLO2 CPT SPSW CDMUT GND V+ MON RTSW CPRVREF RLO1

Line Out＋

C15100n

TLI2

RLI2

R1351k

C140.1u

SPO+

V+

C1710u

NJW1128C21100n

R1651k

C26330n

C6330n

V+

C11u

C21u

C20100n

C291u

V+

C31u

R2300k

V+

C41u

R3300k

C12510p

TR1

V+

LED1R242.2k

R2351k

C301u

MON

SP Out－

Line Out－

TX OUT RXOUT

C23510p

++ C1810u

V+Open

SW1

SW2

SW3

SW4

VR1100k

2

13

LINE IN SP IN

C11 12n

V+

+

C9R4

R5R7

5.1k

R110

*R14

*R170

C24 12n

R215.1k

MIC OUT FO

*R14 : Dummy Load

*R11 : Jumper *R17 : Jumper

*R7 : Jumper

*R21 : Jumper

Fig.0.2 NJW1128 Evaluation-board circuit

Control the sensitivity of transmit and receive

shift

Control speed of conversation switch

and stability

Control the time to shift to Back ground noise

monitor mode

Generate the Voltage used Gain control

Control speed of conversation

switch and stability

NJW1128

– 16 –

<Power Supply Wiring layout> 42pin is sensitive for power supply ripple. Thus, ripple should be less than 10mVp-p. Please use regulator for stable power supply. 1,42pin, other V+ pin, and 43pin(GND) should have lower common impedance as possible. 2,Large capacitor between 42pin and 43pin, in case of that common impedance couldn’t be lower and power supply has larger ripple. And, adding coil in front of bypass capacitor of 42pin is also effective for ripple rejection. Supply same power source to 42pin and 14,15,22,23 pin. They are not able to use on different voltage. Connect de-coupling capacitor to 14,15,22,23 pin. 43pin and 18,19pin should be connected to GND. All V+pin and GND pin should be connected for normal operating. Don’t be Open. Wire lower impedance GND side of capacitor connected to VREF,CPT,CPR,TL01,TL02,RL01,RL02,and CTpin as possible.

1

2

3

4

5

6

7

8

9

10

11

12

13 14 15 16

48 43 42 41 40 39 38 37

36

35

34

33

32

31

30

29

17 18 19 20 21 22

28

27

26

25

2423

47 46 45 44

GND V+

NJW1128

++

V+ V+ V+ V+GND GND

RegulatorVOUT

GND

VIN

VREF CPR RLO1

TLO1

CPTTLO2

RLO2

CT

1,Be lower common impedance.

2,Be larger capacitor when common impedance couldn’t be lower and power supply has larger ripple. Adding coil is also effective for ripple rejection.

NJW1128

– 17 –

[Operating mode] NJW1128 equips operating modes below. Fig.0.4 shows simple NJW1128 diagram. <Tx mode> signal input to mic. In(Transmit side) Tx Attenuator sets +6dB, signal go route.1 though mic in to line amp. At same time, route.2 sets –46dB to stop signal. <Rx mode> signal input to Receive. In(Receive side) Rx Attenuator sets +6dB, signal go route.2 though mic in to line amp. At same time, route.1 sets –46dB to stop signal. <Slow idle mode> environmental noise input or no signal input continuous signal input to mic.input or receive input, or both input no signal Rx attenuator and Tx attenuator set both –20dB. Then, shifting transmit mode or receive mode to half conversation(both route -20dB) gradually. <Fast idle mode> Transmit and Receive input at the same time. To Mic.input and Receive input signal input at the same time, Rx attenuator and Tx attenuator set both –20dB. route1 and 2 shift half conversation(both route –20dB). Shifting transmit mode or receive mode to half conversation(both route -20dB) sharply. We recommend forming filter of mic.amp and receive amp. to filtering some frequency we don’t need. That realizes to stable conversation.

TxAttenuator

AttenuatorControl

LevelDetector


Speaker output

Mic. Input

RxAttenuator

Speaker AMP

LineAmplifier

Transmit to Satellite Unit

MICIN MICOUT TLI2 TLI1 TXO LII LiO- LiO+

RLI2RXOSPISPO-SPO+

MIC

AMP

ReceiveAMP

FIFORLI1

Receive from satellite Unit

LevelDetector


1,Transmit route

2,Receive route

The circuits control 4 mode.

NJW1128

– 18 –

[2wire-4wire convert circuit] NJW1128 2wire application should be mixed or isolated by 2wire-4wire convert circuit Fig0.5 shows conceptual diagram of 2wire - 4wire convert circuit. Each impedance meeting this condition doesn’t transmit VIN1toVout1 and VIN2toVout2. That means transmit side signal doesn’t leak to receive side, opposite side too. This circuit enable to transmit and receive by 2wire.

11

131214 Z

ZZZ

21

232224 Z

ZZZ

Fig.6 shows 2wire –4wire convert circuit consisted of line amp of NJW1128 and Hybrid transformer. Impedance matching Z1 and Z2 enable to operate normally..

More details about equal circuit consisted of Tr or power supply superimposed circuit , refer to other technical

book on phone line.

Z11 Z13

Z12 Z14

Z21

Z22

Z23

Z24

VIN1

VOUT1

VIN2

VOUT2

Fig.0.5 2wire-4wire convert circuit Conceptual diagram

Fig.0.6 2wire –4wire convert circuit consisted of line amp of NJW1128 and Hybrid transformer

-1Line Amplifier

TXO LII LiO- LiO+

VREF

Receive In

to Hybrid Network

Z1

Z2

ReceiveAmplifier

VREF

FIFO

Z1 and Z2 impedance matching makes TXO output signal doesn’t leak to receive side

NJW1128

– 19 –

[Thermal Design] Notice of thermal design on Speaker Amplifier. Fig.0.7 shows Maximum power dissipation of NJW1128(LQFP48-R3) and Ambient temperature Ta. Test condition is EIA/JEDEC STANDARD Test board (76.2x114.3x1.6mm, 2layer, FR-4) mounting and EIA/JEDEC STANDARD Test board (76.2x114.3x1.6mm, 4layer, FR-4) mounting. Calculate appropriate PD to be lower than Pdmax(maximum Power dissipation). Fig.0.8 shows PD and Speaker output power . Actual Pdmax depends on your PCB type, PCB size, wiring. Consider appropriate thermal design.

Pd vs Output PowerV+=5.0V , f=1kHz , Gv=6dB , BW=400Hz-30kHz , Ta=25degC

0

100

200

300

400

500

600

700

0 100 200 300 400 500 600 700

Output Power [mW]

PD

[mW

]

THD=1%THD=3%

Fig.0.8 NJW1128 PD and Speaker output power

0

250

500

750

1000

1250

1500

1750

2000

2250

-40 -20 0 20 40 60 80 100 120Ta (Ambient temperature) [degC]

PDm

ax (M

axim

um p

ower

dis

sipa

tion)

[mW

]

JEDEC 2-Layer Boad

JEDEC 4-Layer Boad

Fig.0.7 NJW1128(LQFP48-R3) PDmax and Ta

NJW1128

– 20 –

1.Receive Attenuator Receive Attenuator has 3 modes depending on base and satellite unit condition.

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Receive Attenuator Gain 1 GR1 RX-mode (Receive) 3.0 6.0 9.0 dB Receive Attenuator Gain 2 GR2 TX-mode (Transmit) -43 -46 -50 dB

Receive Attenuator Gain 3 GR3 Idle-mode (Standby),CPT=CPR=V+ -17 -20 -23 dB

1.Receive Attenuator Gain 1 , (Receive mode :Gain=+6dB) Condition: Receive the signal from satellite unit, and no transmit the signal to satellite unit. 2. Receive Attenuator Gain 2 , (Transmit mode :Gain=-46dB) Condition: Transmit the signal to satellite unit, and no receive signal from satellite unit. 3. Receive Attenuator Gain 3 , (Idle mode :Gain=-20dB) Condition: Both lines are attenuated (-20dB). Receive attenuator mode depends on level controller detection mode. Volume Control Receive Attenuator includes Volume Control. Volume is controlled by resister value connected to VCL pin. Fig.2 shows Volume attenuate vs. Resister value. Volume max.(0dB) : 0, Volume min. (-40dB): 100k .

Fig.2 Volume vs. Resister

Rx Attenuator VolumeControl Attenuation vs RVLCV+=5.0V, f=1kHz, Vin = 200mVrms, Rx-Mode, RecieveAmp = 0dB,

Ta=25degC

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

0 20 40 60 80 100

RVLC [k]

Atte

nuat

ion

[dB

]

NJW1128

– 21 –

2.Transmit Attenuator Transmit Attenuator has 3 modes depending on base and satellite unit condition.

PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT Transmit Attenuator Gain 1 GT1 RX-mode (Receive) 3.0 6.0 9.0 dB Transmit Attenuator Gain 2 GT2 TX-mode (Transmit) -43 -46 -50 dB

Transmit Attenuator Gain 3 GT3 Idle-mode (Standby),CPT=CPR=V+ -17 -20 -23 dB

1.Transmit Attenuator Gain 1 , (Transmit mode :Gain=+6dB) Condition: Transmit the signal to satellite unit, and No receive the signal from satellite unit. 2. Transmit Attenuator Gain 2 , (Transmit mode :Gain=-46dB) Condition: No Transmit the signal to satellite unit, and Receive the signal from satellite unit. 3. Transmit Attenuator Gain 3 , (Idle mode :Gain=-20dB) Condition: Both lines are attenuated (-20dB) Transmit attenuator mode depends on level controller detection mode. Transmit Attenuator doesn’t equip Volume Control.

NJW1128

– 22 –

3.Microphone Amplifier(Transfer Block) Microphone Amplifier is an operational Amplifier amplifying the signal from microphone to line level. Fig.3 shows Block Diagram of Mic.Amp.. Non-inverting input keeps reference voltage inside. Mic.Amp is used as inverting amplifier. The Gain should be 40dB or less. Mic.amp equips Mute function. GND to 0.3V:Active 1.5V to V+:Mute

Microphone

V+

MICIN MICOUT

VREFR2 MicAmplifier

C2


External Parts

Purpose Recommend

value Explanation Note

C10 DC decoupling 100n～10F - C10 and R6 create LPF

(fc=1/2R6*C10) R8 Gain Setting 3k～300k Gv = R8/R6

Input impedance=R6 Recommend Gv<40dB R6 R2

Pop-noise reduction 10k～300k MUTE/ACTIVE swithing

pop-noise reduction C2 100n～1F

MUTE pin Voltage Condition VIH >1.5V MUTE VIL <0.3V ACTIVE

Microphone

V+

MICIN MICOUT

VREFR2 MicAmplifier

C10100n

R856k

C2


R75.1k

C12560p

C1112n

Mic amp is also used creating multiple feedback LPF,HPF,BPF.Fig.3 shows Block Diagram of Mic.Amp (Gv=20dB,fc=4kHz LPF). Frequency except Conversation band should be remove by mic amp filter for stable operating. Refer note.2 about Filter value at the end of this application note.

Fig.3.1 mic amp application example

Fig.3.2 mic amp application example(Gv=20dB,fc=4kHz LPF)

Table.3.1 mic amp application external parts

Table 3.2 mic. amp mute logic

NJW1128

– 23 –

4.Receive Amplifier(Receive Block) Receive Amplifier is an operational Amplifier receiving the signal from satellite unit. Fig.4 shows Block Diagram of Mic.Amp Block Non-inverting input keeps reference voltage inside. Receive Amp is used as inverting amplifier. The Gain should be 40dB or less. Receive Amplifier doesn’t equip Mute function.

FIFO

Recive InR20 R22 C25

ReceiveAmplifier

VREF

External Parts

Purpose Recommend

Value Explanation Note

C25 DC-decoupling 100n to 10F - C25 and R22 create LPF

(fc=1/2R22*C25) R20 Gain setting 3k to 300k Gv = R20/R22

Input impedance=R22 Recommend Gv<40dB R22

Receive amp is also used creating multiple feedback LPF,HPF,BPF. Fig.4.2 shows application example of Receive amplifier (Gv=20dB,fc=4kHz LPF,-40dB/deg). Frequency except Conversation band should be remove by mic amp filter for stable operating.

FIFO

Recive In

R2056k

R225.6k

C25100n

ReceiveAmplifier

VREF

C23510p

R215.1k

C2412n

Fig.4.1 Receive amplifier application example

Fig.4.2 Receive amplifier application example (Gv=20dB,fc=4kHz LPF)

Table.4.1 Recieve amp external parts

NJW1128

– 24 –

5.Line Amplifier(Transfer Block) Line Amplifier transmits the signal from Tx attenuator to satellite unit. Line Amplifier consists of two operational Amplifiers. First Amplifier non-inverting input keeps reference voltage inside. First Amplifier is used as inverting amplifier. Second Amplifier includes –1 fixed Gain. These two amplifiers enable to differential output from single-ended signal.

-1

Line Amplifier

Line Out

TXO LII LiO- LiO+

R12 R13C15

CfL

VREF

External Parts

Purpose Recommend



(fc=1/2R12*C15) R13

Gain setting 3k to 300k Gv=R13/R12 Input impedance=R12

Recommend Gv<40dB R12

CfL Prevent oscillation 10p to100pF Need when oscillate due to wire length and inductance. Normally not required.

-

Line Amplifier may oscillates, long transmission path becoming large capacitive load. In this case, add ceramic capacitor (10p to 100p) between LII and LIO-. LIO+,LIO- should not be short to GND. LIO+,LIO- terminal are biased to V+/2).

Line amp differential output enable to create hybrid circuit. Refer to 2wire-4wire convert circuit.

Fig.5.2 show forbidden circuit example. Line output must not be connected with GND even AD coupling.

-1

Line Amplifier

TXO LII LiO- LiO+

R85.1k

R951k

C11100n

CfL

VREF

LINE Cable

Fig.5.1 Line Amplifier Block

Table.5.1 Line amp external parts

Fig.5.2 Forbidden Circuit

Do not connect to GND.

NJW1128

– 25 –

6.Speaker Amplifier(Receive Block) Speaker Amplifier amplifies the signal from Rx attenuator and drives speaker on Receive block . Speaker Amplifier consists of two operational Amplifiers. First Amplifier’s non-inverting input keeps reference voltage inside. First Amplifier is used as inverting amplifier. Second Amplifier includes –1 fixed Gain. These two amplifiers enable to differential output(BTL output) from single-ended signal. Speaker impedance should be more than 8.

Speaker

-1V+

SPISPO-SPO+

SPSW

R1551k

R165.1k

C20100n

C3

R3

CfS


VREF

RXO

External Parts

Purpose Recommend



(fc=1/2R16*C20) R15

Gain setting 3k to 300k Gv=R16/R15 Input impedance=R12 Recommend Gv<40dB

R16

CfL Prevent oscillation 10p to 100pF Need when oscillate due to wire length and inductance. Normally not required.

-

Reducing pop-noise on Power-on, first start up on Power Down mode , after 1 to 3 sec later, activate SPSW. Adding capacitor and resistor in series between SPO- and SPO+ for phase compensation may improve oscillation characteristics depending on speaker type and inductance of wiring. Resistor should be 10 to 20capacitor should be 1 to 100nF.

Speaker

-1V+

SPISPO-SPO+

SPSW

R15 R16 C20

C3

R3

10~20

VREF

RXO

10n~100n

Fig. 6.1Speaker amplifier application.

Fig.6.2 improve oscillation circuit

Phase compensation

NJW1128

– 26 –

Fig.6.3 shows forbidden circuit example. Speaker Amplifier output must not be connect to GND even AC-couplung.

Speaker

-1

SPISPO-SPO+

VREF

7.Monitor Terminal Monitor Terminal switches Voltage mode depends on NJW1124 condition. Fig.7 shows Monitor terminal Block diagram Receive mode:SW-R is on,SW-T is off. Monitor output is Hi(V+). Transmit mode:SW-R is off,SW-T is on. Monitor output is Lo(GND) Idle mode: mode:SW-R is off,SW-T is off. Monitor output is Hi-impedance.

Fig.7 shows test circuit block diagram. SW-R,SW-T include 300 (typ.V+=5V). Refer to typical characteristics data on datasheet about output level vs.

Load impedance.

Fig.7 Monitor terminal test circuit block diagram

Fig.6.3 Forbidden Circuit

Do not connect to GND

AttenuatorControl

V+V+

MON4.7k

4.7k

190Voltmeter

measuringcircuit

SW-R

SW-T

Mode SW-R SW-TTx Mode OFF ONRx Mode ON OFF

FAST Idle Mode OFF OFFSLOW Idle Mode OFF OFF

Table7.1 Monitor terminal condition

NJW1128

– 27 –

8.Level Detector Block The NJW1124 includes Level Detector Block on transmit block and receive block. Level Detector Block consists of two same detectors and back ground noise monitor. Fig.8(a) shows Level Detector block. The signal(S1 to S4) output each detector transmits to attenuator controller to change the mode. Next 8.1 and 8.2 explain each detector and Background Noise Monitor operation details. About S1 to S4 signals, refer to 8 part., Level detector Compare mic.amp output level(Transmit side) with receive attenuator output level or speaker output(Receive side) Compare Receive amp output level(Receive side) with Transmit attenuator output level or speaker output (Transmit side) Mic amp output level LI2 Receive attenuator RLI2 Receive amo output RLI1 Transmit attenuator TLI1 NJW1128 detects these 4point to judge transmit or receive, and input or no signal. Comparator include 18mV hysteresis. Logic switches being level difference more than 18mV. Fig.8(b) shows hysteresis of the comparator.

Fig.8 Level detector

Table8 Truth table

S1 ：Result comparing RLO2 and TLO2 (RLI2 and TLI2Detecting Base Unit side) RLO2>TLO2 [Rx] TLO2>RLO2 [Tx] S2 ：Result comparing RLO1and TLO1 (RLI1 and TLI1Detecting Satellite Unit side) RLO1>TLO1 [Rx] TLO1>RLO1 [Tx] S3＆S4 ：Output Background Noise Monitor [1]:Detecting signal [0]:Judging noise [x]：Don.t Care [y]：Both C3 and C4 is not 0.

S1 S2 S3 S4 ModeTx Tx 1 X Tx ModeTx Rx y y FAST Idle ModeRx Tx y y FAST Idle ModeRx Rx X 1 Rx ModeTx Tx 0 X SLOW Idle ModeTx Rx 0 0 SLOW Idle ModeRx Tx 0 0 SLOW Idle ModeRX Rx X 0 SLOW Idle Mode

Tx：RLO2Rx：TLO1

Tx : TLI2Rx : RLI1

Level Detector

Level Detector


Tx : RLI2Rx : TLI1

Tx : TLO2Rx : RLO1

Tx : S3Rx : S4

Tx : S1Rx : S2

COMP

18mV12mV

RLO1

TLO1

18mV12mV

RLO2

TLO2

(a) block diagram (b) hysteresis of the comparator

NJW1128

– 28 –

8.1.Level Detector Circuit Level detector circuit detects sound signal on each detecting point.Fig.8.1 shows level detector circuit. Equation 8.1.1 shows voltages on each detecting point Vin and Vo(Voltage difference between Ref).

6

6

1054.0

1054.0026.0 Ri

Vin

LnVo [unit : Volt] ・・・ (8.1.1)

For example, Vin=200mVrms(283mVpeak),Ri=10kVo=103mV. Equation 8.1.1 shows input impedance Ri decides sensitivity level. Choose appropriate value Ci creating HPF with Ri. Cut off frequency is decided Ci and Ri. Isink=Vin/Ri(input current to detect circuit) should be less than 1mA. Minimum Ri value is more than 1kRecommend more than 5k Unwanted frequency signal should be cut by LPF,HPF,BPF created by mic.amp or receive amp.. Refer to note:2 part about more detail. The capacitor connected to TLO1.2,RLO1.2 retains detected voltage level Vo. The charging completes immediately. The discharge completes slowly I3=0.3A. Equation below defines Vo discharge

CoVo /103 7 [unit : V/sec] ・・・ (8.1.2) For example, Co=0.33F, Vc=-0.909V/sec. Level detector is half wave rectifier. It discharges in no detecting half cycle. Thus, too small Co value deteriorates Vo rectify characteristic so background noise monitor wouldn’t work. Too large Co lengthen keeping time, so it lengthen transmit / receiver switching time. And also long keeping time minifies level difference, it cause background noise monitor always judge input signal noise. Please select appropriate Co value by adjusting actual product (more than 0.05F).

External Parts

Purpose Recommend


Cin DC-decoupling 100n to 1F - Cin and Rin create HPF

Rin V-I Convert 5k to 100 k Iin=Vin/Rin Iin > 100F

Each detector Input current should be same.

Co Keep voltage level 0.05 to 1.0 F VC=-0.3A Recommend low current leakage

capacitor. Low value capacitor deteriorated rectifier characteristics.

Fig.9.1 Level detector circuit diagram

CO

I10.54uA

I30.3uA

TLI2,1RLI1,2

TLO2,1RLO1,2Ci Ri

Ref (0.9V)

A

AMP1

D1

D4

I20.54uA

AMP2Input : Vin

IO

D3

D5Isink

D2

Output : Vo

NJW1128

– 29 –

8.2.Back Ground Noise Monitor Background Noise Monitor judges whether the input signal is noise or sound (voice) by TLO2 and RLO2 voltage, and change the mode. The NJW1124 includes the Background noise monitor on transmit side and receive side. Fig.9.2 shows Block diagram of Background noise monitor. Background Noise Monitor inputted from TLO2 or RLO1, operates as follows. 1,On initial state, inverted input is 46mV higher voltage than non-inverted input. COMP output is 0(Lo). 2,When signal input to TLO2 or RLO1, COMP non-inverted input is inputted 2.7 times amplified TLO2 or RLO1 signal. 3,Then, if AMP1 output is higher than 36mV meaning COMP hysteresis, COMP output is 1(Hi). 4,At the same time, CPT and CPR is charged through AMP2. 5, Ccp voltage rises gradually in a certain gradient. Finally, the voltage becomes 46mV higher than AMP1 output. 6,When Ccp voltage reach 36 mV higher than AMP1, COMP output change to 0(Lo). Operation detail is below. 【①,②】 The voltage difference between TLO2 or RLO1 and Ref is amplified 8.6dB on AMP1. The signal from AMP1 inputs 2nd stage AMP2 and comparator (COMP) non-inverting input. The signal from AMP2 having 46mV offset voltage inputs COMP inverting input. COMP inverting voltage is 46mV higher than AMP1 output. Thus, on initial state COMP output is 0(Lo), inputting signal COMP output shift to 1(Hi). 【③～⑥】 At the same time, 0.8A internal current source charges external capacitor, until the CCP voltage reach 46mV higher than AMP2 input voltage. The equivalent below shows CCP voltage charging gradient.

VCCP= 0.8x 10-7/CCP [V/sec] For example, CCP=1F,VCP=0.8V/sec. The COMP non-inverting input voltage reach 36mV meaning COMP hysteresis higher than inverting, COMP output 0(Lo). Fig. 8.2.2(a) shows operation of 1~6 explained before. Fig. 8.2.2(b) shows operation inputting intermittent signal or large shift signal. Back ground noise monitor judges that certain continued signal is noise.

External Parts

Purpose Recommend


Ccp Noise Detect 100nF to 1.0 F - Decide the time detecting noise.

Fig.8.2.1 Block diagram of Noise monitor

RefTx : TLO2Rx : RLO1

AMP1 AMP2 COMP

His.36mV

Tx : CPTRx : CPR

CCP

19kΩ 32kΩ0.8A

46mV

NJW1128

– 30 –

AMP1 Out

Ccp Voltage

Comp out

Comp ：0 (Lo)

Comp : 1 (Hi)

Start Input

36mV 46mV

46mV

8.2.2 Operation of Noise monitor

AMP1 Out

Ccp Voltage

Comp out

(a)Certain continued input signal example (b) intermittent signal or large shift signal example

①

②

③

④

⑤

⑥

NJW1128

– 31 –

9.Attenuator Controller Attenuator Controller controls each mode(Transmit or Receive or idle) by the signal(S1 to S4) from level detector according as table.9.1 below Fig.9.1 shows Attenuator Controller block diagram. Table9.1 shows Switch ON/OFF condition truth table on each mode. CT pin charge external CTR to being VREF=+78mV or –78mV on Tx-mode or Rx-mode(Stx=ON, SRXON,SIDLE=ON). Internal 12A current source circuit charges CCT. Gradient is calculated below. VCCP= 1.2x 10-5/CCT [V/sec] (9.1) for example, CCT=1F,VCCP=12V/sec. 78mV voltage difference takes approximately 6.5msec.

VREF

CT

±12uA

78mV

SRX

STX

600k

CCT

10k

VREF

SFAST

78mV

BufferSIdle

ChargeController

Tx Attenuator

Rx Attenuator

RXO

TXO

Fig.9.1 Attenuator Controller Block Diagram

Mode SRX STX SIdle SFASTTx Mode OFF ON ON OFFRx Mode ON OFF ON OFF

FAST Idle Mode OFF OFF OFF ONSLOW Idle Mode OFF OFF OFF OFF

Table.9.1 Attenuator Controller Truth Table

NJW1128

– 32 –

Idle mode: STX=OFF,SRX=OFF, Sidle=OFF Fast Idle mode: SFAST=ON Slow Idle mode: SFAST=OFF CT voltage become VREF voltage with time constant. Time constant is below.

=RxCCT [Sec] 9.2 R is 600k on SLOW idle mode, 10kon FAST mode.

Buffered CT pin voltage(VCT) controls Tx attenuator and Rx attenuator directly. VCT is calculated below. (GAT(TX) =Gain of Tx attenuator, GAT(RX) =Gain of Rx attenuator,)

026.0exp1.020)(

VREFVLogG CTTXAT [unit : dB] (9.3)

026.0

exp1.020)(VREFVLogG CT

RXAT [unit : dB] ・・・ (9.4)

For example, VCT =Vref + 78mV on Rx-mode, Results are GAT(RX) = -46dB , GAT(RX) = +6dB. VCT =Vref on idle-mode, Results are GAT(RX) = -20dB , GAT(RX) = -20dB. Fig,9,1,2(a),(b) shows these operating. For adjusting, before adjust CT capacitor value, First, adjust TLI1,2 or RLI1,2 resistance value. Second, adjust CPT,CPR capacitor value. If after adjust 2 method adjust is not enough, adjust CT pin capacitor 1F to other value. (Fast attenuating or shifting is too slow.)

When measuring CT pin, use high impedance measuring equipment (recommend more than 1G), because CT pin is high impedance and attenuator is very sensitive to CT pin voltage. Dust and Condensation may prevent normal operation.

VCT,GAT(RX) vs timeCCT=1F, SLOW Idle Mode

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0 200 400 600 800 1000 1200 1400 1600 1800 2000

time [msec]

V CT

- VR

EF [m

V]

-50

-40

-30

-20

-10

0

10

GAT

(RX)

, G

AT(T

X)

[dB]

VCT-VREF

GAT(RX)

GAT(TX)

SLOW Idle Mode

Fig.9.2 Attenuator Controller Operation (a) VCT Response example (b) Response to SLOW idle mode

VCT, GAT(RX) , GAT(TX) vs timeCCT=1F

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.1

0 5 10 15 20 25

time [msec]

VC

T - V

RE

F [V

]

-50

-40

-30

-20

-10

0

10

GAT

(RX)

, G

AT(T

X) [d

B]

VCT-VREF

GAT(RX)

GAT(TX)

VCT-VREF=78mV

GAT(RX) = +6dB

GAT(TX) = -46dB

GAT(RX) = GAT(RX) = -20dB

NJW1128

– 33 –

10.RT Switch RTSW shifts the mode forcibly. RTSW changes the CTpin voltage forcibly to shift the mode. Ex.9 shows the response to RTSW.

Table 10.1 RTSW Truth Table Parameter Symbol Min. Typ. Max. Unit

Low Level Input Voltage VIL 0 - 0.3 V

High Level Input Voltage VIH V+-0.3 - V+ V

Table 10.2 NJW1128 mode and RTSW condition Condition Symbol Operation

VIH Rx Mode Receive mode priority. OPEN ※ AUTO Receive mode and Transmit mode are automatically switched.

VIL Tx Mode Transmit mode priority. ※ Open or V+/2 voltage. RTSW shifts the mode forcibly. Table.10.2 and 10.2 shows the response to RTSW. It independent on input level and signal input or not. RTSW change the mode . The mode doesn’t change when RTSW working. RTSW Detecting voltage switches Force Transmit mode, priority Receive mode, Auto mode(normal hands-free mode). Fig.10.1 shows internal circuit block. Table 10.3 and 10.4 shows Switching Operation.

VREF(V+/2)

600k

V+

RTSW Comp1

Comp2 Force RX(Internal)

0.3V~1.0V

0.3V~1.0V

Force TX(Internal)

Fig.10.1 Internal circuit of RTSW

RTSW Voltage Force Rx Force TxGND ~ 0.3V Lo Hi0.3V ~ 1.0V Lo transition range

1.0V ~ (V+ -1.0V) Lo Lo (V+ -1.0V) ~ (V+ -0.3V) transition range Lo

(V+ -0.3V) ~ V+ Hi Lo

Table10.3 Truth Table RTSW voltage Table 10.4 Operating mode

Force RX Force TX ModeLo Lo Auto ModeLo Hi Tx ModeHi Lo Rx ModeHi Hi not supported

NJW1128

– 34 –

Notes:1 To reduce Pop-Noise of power-on and off. Appropriate power supply sequence reduces pop-noise. Initial condition: No power supply. SPSW=MUT=GND(less than 0.3V), CD=V+ [Power-on sequence] 1.Power-on NJW1128. Concurrently the circuit which connected to Receive In and Mic. in power on. 2.After 1 sec, Activate Speaker Amp of NJW1128(SPSW GND to V+) [Power-off sequence] 1.Speaker Amplifier shift standby mode (SPSW V+ to GND). 2.NJW1128 power off. Concurrently, the circuit which connected to Receive In and Mic.amp power off

NJW1128

– 35 –

Notes:2: Filter circuit using Receive amplifier, Mic. Amplifier, Line amplifier. Receive amplifier, Mic. Amplifier, Line amplifier enable to form active filter circuit which is 1st order or 2nd order, HPF or LPF or BPF. Example is below. Example shows that receive amplifier version, but mic.amp and line amp also are able to create filter on same way. 1.1st order HPF,LPF circuit example Fig.2.1 shows 1st order (-6dB/oct) HPF, LPF circuit. Combining HPF formed by Co and R1, and LPF formed by C1 and R2, forms BPF. (Co should be also used typical application as DC decoupling.)

10)( 2

1RC

f HPFC

21)( 2

1RC

f LPFC

2. 2nd order LPF circuit example Fig.2.2 shows 2nd order (-12dB/oct) LPF circuit. Same as 1st order filter, Co should be used as DC decoupling. It works as BPF. C2 selecting arbitrarily, Butterworth filter forming coefficient is as below.

2)(1 22

1CfG

RLPFC

2)(2 22

1Cf

RLPFC

2)(3 )1(22

1CfG

RLPFC

21 )1(2 CGC GainG :

fC(HPF) is same as 1st order type above

+6dB/oct

-6dB/oct

Response

FrequencyResponsefc(HPF) fc(LPF)

Fig.2.1 1st order HPF,LPF circuit example Ref

Receive In

C0 R1

C1

R2

FO

FI

Fig.2.2 2nd order LPF circuit example

+6dB/oct -12dB/oct

Response

FrequencyResponsefc(HPF) fc(LPF)

Ref

Receive In

C0 R1

C2R3

C1

R2

FI

FO

Ref

Receive In

C0 R1

C2R3

C1

R2

FI

FO

NJW1128

– 36 –

Fig.2.3 shows LPF(Gain=20dB,fc(LPF)=4kHz) circuit example. 3.2nd order HPF circuit example Fig.2.4 shows 2st order (+12dB/oct) HPF circuit. Co=C2, Butterworth filter forming coefficient is as below.

)/12(2

20)(

1 GCfR

HPFC

0)(2 2

12Cf

GRHPFC

GCC 0

1

20 CC

GainG : Fig.2.5 shows HPF(Gain=20dB,fc(LPF)=200Hz) circuit example.

Ref

Receive In

C0

R2C2

FOR1

C1

FI

Ref

Receive In

100n

160k

100n

FO5.6k

FI

10n

Fig.2.4 2nd order HPF circuit example.

Fig.2.5 2nd order HPF circuit example. Gain=20dB,Fc(HPF)=200Hz, Butterworth filter

Fig.2.3 2nd order LPF circuit example Gain=20dB,fc(LPF) = 4kHz, Butterworth filter

Ref

Receive In

C0

510p

5.1k

12n

56k

FI

FO

5.6k

NJW1128

– 37 –

3.1nd order BPF circuit example Fig.2.6 shows 1st order (+12dB/oct) HPF circuit. Butterworth filter forming coefficient is as below.

G

RR2

21

212

213 4 RRQ

RRR

31

31

RRRRR

RRfCC

BPFC 3)(21 2

1

torQualityFacQ : GainG :

Actually, it also works as HPF. Fig.2.7 shows BPF(Gain=20dB,fc(LPF)=1kHz,Qyality Factor=3) circuit example.

Fig.2.6 1nd order BPF circuit example.

Fig.2.7 1nd order BPF circuit example. Gain=20dB,fc(HPF)=1kHz, Quality Factor=3

Ref

Receive InFO

FI

R1C0

R3

R2C1

C2

Ref

Receive InFO

FI

C0

6.2k

100k10n

10n5k

NJW1128

– 38 –

Notes:3 Other application. 1.Disable Background Noise Monitor Fig.8.2.1 shows stopping Background Noise Monitor function. Being CPT,CPR pin voltage lower than AMP1(0.3V~0.6V) output voltage keep Comp output ‘1’. This can stop to shift background noise monitor mode, even if continued signal input. It means keeping transmit mode or receive mode. However, when transmit and receive signal input at the same time, shift to Fast idle mode. Fig3.1 shows Stopping Background noise monitor block diagram. 1. Supply Vref (reference voltage) to other circuit

Vref circuit including NJW1128 is not able to supply reference voltage directly. Supplying Vref needs external Buffer amp.(Op.amp) like Fig.3.31 below. Supplying Without Buffer amp. causes deteriorate cross talk and abnormal operation by external circuit influence. In case that Buffer amp can’t prepare, make Vref circuit outside NJW1128 by resistor and capacitor like Fig.3.3.2.


CPTCPR

NJW124

Control

Hi : BNM DisableLo : BNM Enable

Fig3.1 Background Noise Monitor mode Enable/Disable control

V+

VREF120k

120k

190

+1 >10

InternalCircuit

ExtarnalVREFSupply

NJW1128

Fig.3.3.1 Supply Vref(Reference Voltage) to external circuit 1

V+

10k

10k +

ExtarnalVREFSupply

220

Fig.3.3.2 Supply Vref(Reference Voltage) to external circuit 2

[CAUTION] The specifications on this databook are only

given for information , without any guarantee as regards either mistakes or omissions. The application circuits in this databook are described only to show representative usages of the product and not intended for the guarantee or permission of any right including the industrial rights.

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