AM79535 Datasheet, PDF (1/20 Pages) Advanced Micro Devices – Subscriber Line Interface Circuit

Am79534/Am79535
Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
s Programmable constant-current feed
s Line-feed characteristics independent of
battery variations
s Programmable loop-detect threshold
s On-chip switching regulator for low-power
dissipation
s Pin for external ground-key noise-filter
capacitor available
s Ground-key detect
s Two-wire impedance set by single external
impedance
s Polarity reversal feature
s Tip Open state for ground-start lines
s Test relay driver optional
s On-hook transmission
BLOCK DIAGRAM
A(TIP)
HPA
HPB
B(RING)
DA
DB
VREG
L
VBAT
BGND
Two-Wire
Interface
Ground-Key
Detector
Ring Relay Driver
Test Relay Driver
Input Decoder
and Control
Signal Transmission
Power-Feed
Controller
Switching Regulator
Off-Hook Detector
Ring-Trip Detector
CHS
QBAT CHCLK
VCC VEE
Notes:
1. Am79534—E0 and E1 inputs; ring and test relay drivers sourced internally to BGND.
AGND
2. Am79535—E0 and E1 inputs; ring relay driver sourced internally to BGND; ground-key filter pin.
3. Current gain (K₁) = 1000 for all parts.
RINGOUT
TESTOUT
C1
C2
C3
C4
E1
E0
DET
GKFIL
VTX
RSN
RD
RDC
16854C-01
Publication# 16854 Rev: D Amendment: /0
Issue Date: October 1999