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Am79M574
Metering Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
Progr...
www.DataSheet4U.com
Am79M574
Metering Subscriber Line Interface Circuit
DISTINCTIVE CHARACTERISTICS
Programmable constant-resistance feed Programmable loop-detect threshold Ground-key detect Performs polarity reversal Line-feed characteristics independent of battery variations Test relay driver optional
Supports 2.2 Vrms metering (12 and 16 kHz) On-chip switching
regulator for low-power dissipation Two-wire impedance set by single external impedance Tip Open state for ground-start lines On-hook transmission
BLOCK DIAGRAM
Ring Relay Driver A(TIP) Test Relay Driver Ground-Key Detector HPA Two-Wire Interface HPB Signal Transmission Off-Hook Detector B(RING) DA DB VREG L VBAT BGND CHS QBAT CHCLK VCC VEE AGND
16857C-001
RINGOUT TESTOUT C1 C2 C3 C4 E1 E0 DET
Input Decoder and Control
VTX RSN
Power-Feed Controller Ring-Trip Detector
RD RDC
Switching
Regulator
Notes: 1. Am79M574—E0 and E1 inputs; ring and test relay drivers sourced internally to BGND. 2. Current gain (K1) = 1000.
Publication# 080135 Rev: E Amendment: /0 Issue Date: October 1999
ORDERING INFORMATION Standard Products
Legerity standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed by a combination of the elements below.
Am79M574
J
C
TEMPERATURE RANGE C = Commercial (0°C to 70°C)*
PACKAGE TYPE J = 32-Pin Plastic Leaded Chip Carrier (PL 032)
PERFORMANCE GRADE Blank = Standard Specification –1 = Performance Grading...