NJW1124 Datasheet, PDF (1/29 Pages) New Japan Radio – Voice Switched Speakerphone circuit

NJW1124
Voice Switched Speakerphone circuit
! GENERAL DESCRIPTION
The NJW1124 is a Voice Switched Speakerphone Circuit.
NJW1124 includes all of functions processing a high quality hands–free
speakerphone system, such as the necessary amplifiers ( Microphone ,
Receive ,Line), attenuators, level detectors functions.
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
• Force to Receive, Transmit, or Idle modes
• Mode –watching monitor
• Attenuator gain range between Transmit and Receive
• Microphone amplifier with mute function
• Background noise monitor for each path
• Volume control range
• 4-point signal sensing
• Microphone and Receive Amplifiers pinned out for flexibility
• Package Outline
2.9 to 4.5V
52dB
40dB
SSOP32
! PACKAGE OUTLINE
NJW1124V
! BLOCK DIAGRAM
Microphone
C6 R2
100n 5.1k
R3
C7
51k
100n
M CI
MCO
R4
51k
TLI2
C8 C9 R6
100n 100n 5.1k
R5
10k
TLI1 TXO
LII
R7
51k
C10
LiO-
LiO+
Line Out
V⁺
V⁺
R1
300k
C1
1µ
C3
470n
C4
470n
C2
1u
M UT
TLO2
RLO2
CPT
C23
1µ
VREF
VREF2
VREF
Mic
Amplifier
Tx Attenuator
Lev el
Detector
Background
NoiseMonitor
Attenuator
Control
VREF
-1
Line Amplifier
Background
NoiseMonitor
Lev el
Detector
C11
V⁺
1µ
M onit or
CT
RTSW
C5
1µ
V⁺
C22
CPR
1µ
TLO1
RLO1
C20
470n
C21
470n
BIAS
IC1
NJW1124
Rx Attenuator
1.2µ A
Receive
Amplifier
GND
VREF
V⁺
R10
15k
C15
1µ
Speaker
IC2
NJU7084
Power Amplifier
5.0V
+ ^C16
10µ _C13
1µ
RXO RLI2
R11
C17 10k
100n
C14 1 µ
R9
22k
R8 C12
11k 100n
VLC
R12
51k
R_VLC
RLI1 FO
C18
100n
R13
5. 1k
FI
R14 C19
5.1k 100n
Recive In
–1–