TEA1085 Philips Semiconductors, TEA1085 Datasheet - Page 13

• Manufacturer Part Number: TEA1085
• Description: Listening-in circuit for line-powered telephone sets
• Manufacturer: Philips Semiconductors

Philips Semiconductors
March 1992
handbook, full pagewidth
handbook, full pagewidth
Listening-in circuit for line-powered
telephone sets
Where:
k
Where:
Change of receive gain
=
t
--- -
T
1
=
--------- -
G
G
vo
Fig.10 Dynamic behaviour of Larsen limiter (in open-loop condition).
v
V LLC
V DTI
0.5 V
0 V
V DTI1
1
V DTI
slope S li
Fig.11 Definition of duty cycle k.
listen-in mode
t 1
T
t ad
13
Larsen mode
t LAa
slope S la
t LAr
MGR040
listen-in mode
Nominal receive gain = 20 log G
V DTI
^
TEA1085; TEA1085A
0.63 V
MGR039
k
=
Preliminary specification
0.5 –
arc
--------------------------------------- -
sin
vo
= 35 dB
V
-------------- -
V ˆ
DTI1
DTI