U4091B Datasheet, PDF (3/11 Pages) TEMIC Semiconductors – Programmable Telephone Audio Processor

TELEFUNKEN Semiconductors
U4091B
Pin Description
Pin Symbol
Function
DTMF Input for DTMF signals, also used
for the answering machine and
handsfree input
MICO Output of microphone preamplifier
MIC 2
MIC 1
Non-inverting input of microphone
amplifier
Inverting input of microphone
amplifier
PD Active high input for reducing the
current consumption of the circuit,
simultaneously V_L is shorted by an
internal switch
IND The internal equivalent inductance
of the circuit is proportional to the
value of the capacitor at this pin, a
resistor connected to ground may be
used to reduce the dc line voltage
V_L
GND
SENSE
Line voltage
Reference point for dc- and
ac-output signals
A small resistor (fixed) connected
from this pin to V_L sets the slope of
the dc characteristic and also effects
the line length equalization
characteristics and the line current
at which the loudspeaker amplifier
is switched on
V_B Unregulated supply voltage for
peripheral circuits (voice switch),
limited to typically 7 V
SAO
V_MPS
V_MP
Output of loudspeaker amplifier
Unregulated supply voltage for µP,
limited to 6.3 V
Regulated supply voltage 3.3 V for
peripheral circuits (especially
microprocessors), maximum output
current: 2 mA
SWOUT Output for driving external
switching transistor
COSC 40 kHz oscillator for ringing power
converter
VRING Input for ringing signal
THA Threshold adjustment for ringing
frequency detector
RFDO Output of ringing frequency detector
LIDET Line detect; output is low when the
line current is more than 15 mA
Pin Symbol
Function
TSACL Time constant of anti-clipping of
speaker amplifier
SA I Speaker amplifier input (for
loudspeaker, tone ringer and
handsfree use)
RLO1 Receive level output 1
RLI1 Receive level input 1
MICHF Handsfree Mic input
BNMT Background noise monitor in trans-
mit direction
RLI2 Receive level input 2
RLO2 Receive level output 2
C Clock
D Data
Reset Reset
IREF
Internal reference current
generation; RREF = 62 kΩ;
IREF = 20 µA
STO Side tone reduction output
output resistance is approx. 300 Ω,
maximum load impedance: 10 kΩ.
V_M Reference node for microphone-
earphone and loudspeaker amplifier,
m ^{supply for electret microphone}
(IM ≤ 300 A)
RECO 2 Inverting output of receiving
amplifier
STI S Input for side tone network (short
loop) or for answering machine
STI L Input for side tone network (long
loop)
RAC Input of receiving amplifier for ac
coupling in feedback path
RECO 1 Output of receiving amplifier
TTXA Time constant of anticlipping in
transmit path
W RECIN Input of receiving path; input
impedance is typically 80 k
TXIN Input of intermediate transmit stage,
input resistance is typically 20 kΩ
TLDI Transmit level detector input
TLDO Time constant of level detector for
transmit voice recognition
TS Time constant for switching
Rev. A1: 12.07.1995
Preliminary Information
3 (11)