U4092B Datasheet, PDF (7/32 Pages) TEMIC Semiconductors – Monolithic Integrated Feature Phone Circuit

TELEFUNKEN Semiconductors
Pin Symbol
Function
17 VRING Input for ringing signal
18 THA Threshold adjustment for ringing
frequency detector
19 RFDO Output of ringing frequency detector
20 IMP- Control input for selection of line
SEL impedance
1. 600 Ω
2. 900 Ω
3. Mute of second transmit stage
(TXA); also used for indication of
external supply (answering
machine); last chosen impedance is
stored.
21 TSACL Time constant of anticlipping of
speaker amplifier
22 GSA Current input for setting the gain of
the speaker amplifier. Adjustment
characteristic is logarithmical. For
RGSA > 2 MΩ, the speaker
amplifier is switched off.
23 SA I Speaker amplifier input (for
loudspeaker, tone ringer and
handsfree use)
24 MUTX 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 a
confidence signal during dialing.
3) Input DTMF used for answering
machine and handsfree use; receive
branch not affected.
25 ATAFS 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.
26 INLDT Input of transmit level detector
27 INLDR Input of receive level detector
U4092B
Pin Symbol
Function
29 TLDT Time constant of transmit level
detector
29 TLDR Time constant of receive level
detector
30 AGA Automatic gain adjustment with line
current. A resistor connected from
this pin to GND sets the starting
point. Max. gain change is 6 dB.
31 IREF Internal reference current
generation; RREF = 62 kΩ; IREF =
20 µA
32 STO Side tone reduction output. Output
resistance is approximately 300 Ω.
Maximum load impedance is 10 kΩ.
33 V_M Reference node for
microphone-earphone and
m ^{loudspeaker amplifier. Supply for}
electret microphone (IM ≤ 300 A).
34 RECO Output of receiving
amplifier
35 STI Input for side tone network
36 RAC Input of receiving amplifier for ac
coupling in feedback path
37 G_R A resistor connected from this pin to
GND sets the receiving amplification
of the circuit; amplifier RA1 can be
muted by applying VMP to GR
38 TTXA Time constant of anticlipping in
transmit path
W 39 RECIN Input of receiving path; input
impedance is typically 80 k
40 TXIN Input of intermediate transmit stage,
input resistance is typically 20 kΩ
Rev. A1: 24.01.1995
Preliminary Information
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