AM79M574

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...