View l3234 datasheet:

L3234 L3235N ® HIGHLY INTEGRATED SLIC KIT TARGETED TO PABX AND KEY SYSTEM APPLICATIONS HIGHLY INTEGRATED SUBSCRIBER LINE INTERFACE KIT FOR PABX AND KEY SYS- TEM APPLICATIONS IMPLEMENTS ALL KEY ELEMENTS OF THE BORSCHT FUNCTION INTEGRATED ZERO CROSSING BALANCED RINGING INJECTION ELIMINATES EXTER- NAL RELAY AND CENTRALISED RINGING GENERATOR HEPTAWATT ZERO NOISE INJECTED ON ADJACENT LINES DURING RINGING SEQUENCE ORDERING NUMBER: L3234 LOW POWER IN STANDBY AND ACTIVE MODES BATTERY FEED WITH PROGRAMMABLE LIMITING CURRENT PARALLEL LATCHED DIGITAL INTERFACE SIGNALLING FUNCTIONS (OFF HOOK, GND-KEY) LOW NUMBER OF EXTERNAL COMPO- NENTS INTEGRATED THERMAL PROTECTION TQFP44 INTEGRATED OVER CURRENT PROTEC- TION ORDERING NUMBER: L3235N 0°C TO 70°C: L3234/L3235N -40°C TO 8