AM79M535 Datasheet, PDF (1/18 Pages) Advanced Micro Devices – Metering Subscriber Line Interface Circuit

Am79M535
Metering 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
BLOCK DIAGRAM
s Ground-key detect
s Two-wire impedance set by single external
impedance
s Performs polarity reversal
s Tip Open state for ground-start lines
s Supports 2.2 Vrms metering (12 and 16 kHz)
s On-hook transmission
A(TIP)
Ring Relay Driver
RINGOUT
HPA
Two-Wire
Interface
Ground-Key
Detector
Input Decoder
and Control
C1
C2
C3
E1
E0
DET
HPB
Signal Transmission
Off-Hook Detector
B(RING)
DA
DB
VREG
L
VBAT
BGND
Power-Feed
Controller
Switching Regulator
Ring-Trip Detector
CHS QBAT CHCLK
VCC VEE AGND
Notes:
1. Am79M535—E0 and E1 inputs; ring relay driver sourced internally to BGND; ground-key filter pin.
2. Current gain (K₁) = 1000.
GKFIL
VTX
RSN
RD
RDC
16856B-001
Publication# 16856 Rev: E Amendment: /0
Issue Date: October 1999