AM79R70 Datasheet, PDF (1/17 Pages) Advanced Micro Devices – Ringing Subscriber Line Interface Circuit

PRELIMINARY
Am79R70
Ringing Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
s Ideal for ISDN-TA and set top applications
s On-chip ringing with on-chip ring-trip detector
s Low standby state power
s Battery operation:
— V_BAT1: –40 V to –67 V
— V_BAT2: –19 V to V_BAT1
s On-chip battery switching and feed selection
s On-hook transmission
s Polarity reversal option
s Programmable constant-current feed
s Programmable Open Circuit voltage
s Programmable loop-detect threshold
s Current gain = 1000
s Two-wire impedance set by single component
s Ground-key detector
s Tip Open state for ground-start lines
s Internal V_EE regulator
(no external –5 V power supply required)
s Two on-chip relay drivers and snubber circuits
BLOCK DIAGRAM
RTRIP1
RTRIP2
A(TIP)
HPA
HPB
B(RING)
VBAT2
VBAT1
Two-Wire
Interface
Switch
Driver
Ring-Trip
Detector
Ground-Key
Detector
Off-Hook
Detector
Signal
Transmission
Power-Feed
Controller
Relay
Driver
Relay
Driver
Input Decoder
and Control
RYOUT2
RYE
RYOUT1
D1
D2
C1
C2
C3
E1
DET
RD
VTX
RSN
RINGIN
RDC
RDCR
RSGL
RSGH
B2EN
VCC VNEG BGND AGND/DGND
This document contains information on a product under development at Advanced Micro Devices. The information
is intended to help you evaluate this product. AMD reserves the right to change or discontinue work on this proposed
product without notice.
Publication# 21776 Rev: B Amendment: /0
Issue Date: July 1998