Am79R79
Ringing Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
I
Ideal for short-loop applications
I
Ideal for ISDN terminal adaptor and fixed radio
access applications
I
On-chip ringing with on-chip ring-trip detector
I
Low standby state power
I
Battery operation:
— V
BAT1
: –40.5 V to –75 V
— V
BAT2
: –19 V to V
BAT1
I
On-chip battery switching and feed selection
I
On-hook transmission
I
Two-wire impedance set by single external
impedance
I
Programmable constant-current feed
I
Programmable Open Circuit voltage
I
Programmable loop-detect threshold
I
Current gain = 1000
I
Ground-key detector
I
Tip Open state for ground-start lines
I
Polarity reversal option available
I
Internal V
EE
regulator (no external –5 V power
supply required)
I
Two on-chip relay drivers and snubber circuits
(32 PLCC)
BLOCK DIAGRAM
Relay
Driver
RTRIP1
RTRIP2
Relay
Driver
RYOUT2
RYE
RYOUT1
D1
D2
C1
C2
C3
E1
DET
RD
VTX
RSN
RINGIN
RDC
RDCR
A(TIP)
Ring-Trip
Detector
HPA
Two-Wire
Interface
HPB
Signal
Transmission
B(RING)
Power-Feed
Controller
Ground-Key
Detector
Off-Hook
Detector
Input Decoder
and Control
VBAT2
Switch
Driver
VBAT1
RSGL
RSGH
B2EN
VCC VNEG BGND AGND/DGND
Publication#
19752
Rev:
G
Amendment:
/0
Issue Date:
October 1999
AMD [ ADVANCED MICRO DEVICES ]
