U4089B-PFN ATMEL [ATMEL Corporation], U4089B-PFN Datasheet - Page 4

• Manufacturer Part Number: U4089B-PFN
• Description: Monolithic Integrated Feature Phone Circuit
• Manufacturer: ATMEL [ATMEL Corporation]

Pin Description
4
Note:
Pin
24
25
26
27
28
29
30
31
32
33
36
39
40
41
42
44
Filters against electromagnetic interference (EMI) are located at the Pins MIC1, MIC2, RECIN and STI.
U4089B-P
Symbol
RECIN
ATAFS
INLDR
MUTX
INLDT
RECO
TLDR
TTXA
TLDT
IREF
AGA
STO
STI
V
G
G
M
R
T
Function
Three-state input of transmit mute:
1) Speech condition; inputs MIC1/MIC2 active.
2) DTMF condition; input DTMF active. A part of the input signal is passed to the receiving amplifier as
3) Input DTMF used for answering machine and hands-free use; receive branch is not affected.
Attenuation of acoustical feedback suppression. Maximum attenuation of AFS circuit is set by a resistor
at this pin. Without the resistor, AFS is switched off.
Input of transmit level detector.
Input of receive level detector.
Time constant of transmit level detector.
Time constant of receive level detector.
Automatic gain adjustment with line current. A resistor connected from this pin to GND sets the starting
point. Maximum gain change is 6 dB.
Internal reference current generation; RREF = 62 k ; IREF = 20 µA
Side-tone reduction output. Output resistance is approximately 300 . Maximum load impedance is
10 k
Reference node for microphone-earphone and loudspeaker amplifier. Supply for electret microphone
(IM
Input for side-tone network.
Output of receiving amplifier.
A resistor connected from this pin to GND sets the receiving amplification of the circuit; amplifier RA1
can be muted by applying V
Time constant of anti-clipping in transmit path.
Input of receiving path; input impedance is typically 80 k
A resistor from this pin to GND sets the amplification of microphone and DTMF signals; the input
amplifier can be muted by applying V
a confidence signal during dialing.
300 mA).
MP
to G
R
.
MP
to G
T
.
4518A–CORD–05/02