AM7945 Datasheet, PDF (1/18 Pages) Advanced Micro Devices – Subscriber Line Interface Circuit

Am7945
Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
s Programmable constant-current feed
s Current gain = 200
s Programmable loop-detect threshold
s Low power Standby state
s Ground-key detector
s Tip Open state for ground-start lines
s –19 V to –56.5 V battery operation
BLOCK DIAGRAM
TMG
s On-chip Thermal Management (TMG) feature
s Two-wire impedance set by single external
impedance
s On-hook transmission
s On-chip ring relay driver and relay snubber
circuit
s Ideal for low cost PABX and key telephone
systems
A(TIP)
HPA
HPB
B(RING)
DA
DB
VBAT
BGND
Two-Wire
Interface
Ground-Key
Detector
Signal
Transmission
Off-Hook
Detector
Power-Feed
Controller
Ring-Trip
Detector
Ring Relay
Driver
Input Decoder
and Control
RINGOUT
C1
C2
C3
E0
E1
DET
RSN
VTX
RD
RDC
CAS
VCC VEE AGND/DGND
Publication# 18408 Rev: D Amendment: /0
Issue Date: October 1999