Universal Digital Loop Transceiver (UDLT-3)
Pin Selectable Master/Slave
Limited Distance Modem

The MC145423 is a CMOS integrated circuit designed to be one of the major building blocks in digital subscriber voice/data telephone systems and remote data acquisition and control systems.
The UDLT-3 incorporates into one device, all the functionality of the MC145421 (ISDN UDLT-2 master), MC145425 (ISDN UDLT-2 slave), MC145422 (UDLT-1 master), and MC145426 (UDLT-1 slave).
Since these modes/functions are pin selectable, the MC145423 can be used in telephone switch line cards, as well as remote digital telsets or data terminals.

• VDD = 4.5 V to 5.5 V
• 28-Pin SOIC and TSSOP Packages
• Protocol Independent
• Pin Controlled Power-Down
• LI Sensitivity Control in Master Mode
• 2.048 MHz Output in Slave Mode

UDLT-2 Features
• Synchronous Full Duplex 160 kbps Voice and Data Communications in a 2B+2D Format for ISDN Compatibility
• Provides CCITT Basic Access Data Transfer Rate (2B+D) for ISDNs on a Single Twisted Pair Up to 1 km on 26 AWG or Larger Cable

UDLT-1 Features
• Pin Controlled Loopback
• Automatic Power-Up/Down (Slave)
• Full Duplex Synchronous 64 kbps Voice/Data Channel and Two 8 kbps Signaling Data Channels Over One 26 AWG Wire Pair Up to 2 km