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: — VBAT1: –40 V to –67 V — VBAT2: –19 V to VBAT1 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 VEE
regulator (no external –5 V power supply required) s Two on-chip rel...