U3750BM Datasheet, PDF (3/20 Pages) TEMIC Semiconductors – One Chip Telephone Circuit

TELEFUNKEN Semiconductors
U3750BM
Pin Description
Pin Symbol Function
1
C4 Keyboard input
2
C3 Keyboard input
3 FLASH Flashing selection
4 DC/FV Dialling selection (33/66 pulse,
40/60 pulse or DTMF)
5
OL Open line output
6 RESET Output reset
7 TEEIN Test pins
8
SHEN Test pins
9
NC Not connected
10
V_RAM RAM and internal logic supply
11
V_CC Power supply for peripherals
12
V_L Line voltage
13 OSCAB Test pin
14
EC Extra current for peripherals or
can be used to dissipate power
for high line current applications.
15 TESTR Test pin
16
GND Ground
17
NC Not connected
18
AGA Line length AGC adjustment
19
I_REF Bias adjustment
20 SELF Electronic self input
21 RGAB DC characteristic slope
adjustment
22
MIC₁ Microphone input
Pin Symbol Function
23
MIC₂ Microphone input
24
ZAC Dynamic impedance adjustment
25 EM/FILT First sending stage output
26 MOD Modulator output
27 EM/MF Second sending stage input and
DTMF input
28
ACL Anticlipping time constant
adjustment
29
E2 Receiver output
30
E1 Receiver output
31
NC Not connected
32
REC Receiver input
33
ZAL Sidetone network
34 OUT1 Buzzer output
35 OUT2 Buzzer output
36
VIR Ringing supply
37
CK Ceramic input (455 KHz)
38
PAIR Adjustment between two pairs of
ringing frequencies
39 BEAT Beat adjustment of each pair of
ringing frequencies
40
MF DTMF output
41
C1 Keyboard inputs
42
C2 Keyboard inputs
43
C6 Keyboard inputs
44
C5 Keyboard inputs
Rev. A1: 16.07.1996
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