TEA1068T Philips Semiconductors, TEA1068T Datasheet - Page 15

• Manufacturer Part Number: TEA1068T
• Description: Versatile telephone transmission circuit with dialler interface
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Table 1 Values of resistor R6 for optimum line loss compensation, for various usual values of exchange supply
1996 Apr 23
handbook, full pagewidth
Versatile telephone transmission circuit
with dialler interface
Voltage gain is defined as; G
the DTMF input, MUTE should be HIGH. Inputs not under test should be open.
V
exch
24
36
48
60
voltage V
C1
(V)
100 F
10 F
V i
V i
exch
Fig.14 Test circuit for defining voltage gain of MIC+, MIC and DTMF inputs.
R
and exchange feeding bridge resistance R
exch
v
= 20 log V
61.9
100
140
= 400
X
o
/V
MIC
MIC
DTMF
MUTE
PD
IR
i
. For measuring the gain from MIC+ and MIC , the MUTE input should be LOW or open, for measuring
V EE
V CC
C3
4.7
F
REG
R
TEA1068
exch
620
AGC
R1
48.7
78.7
110
R6
= 600
X
STAB
15
R5
3.6
k
LN
SLPE
R6 (k )
GAS1
GAS2
exch
GAR
R9
20
QR
QR
; R9 = 20
R
exch
R4
100 k
R7
68 k
93.1
120
68
= 800
X
100 pF
100 F
C7 1 nF
C4
100 pF
C6
600
R L
MBH138
I line
V o
Product specification
R
exch
10 to 140 mA
TEA1068
60.4
102
= 1000
82
X