PM4351-RGI

The PM4351-RGI from Microchip Technology is a single-channel E1/T1 Line Interface Unit (LIU) designed for telecommunications equipment. It supports both short-haul and long-haul operation with integrated clock and data recovery (CDR), eliminating the need for external clock recovery components. The device features internal impedance matching for both E1 (75Ω coaxial / 120Ω twisted pair) and T1 (100Ω twisted pair) line interfaces. The PM4351 provides both parallel and serial microprocessor interface options for flexible system integration. Built on 0.35μm process technology, it operates from a single 3.3V supply and supports data rates up to 8.192Mbps, covering E1 (2.048Mbps), T1 (1.544Mbps), and higher-rate clear-channel applications.

The PM4351-RGI interfaces between the digital system backplane and the E1/T1 transmission line. On the receive side, the line receiver amplifier accepts the incoming signal from the line transformer, applies internal impedance matching, and passes it to the CDR circuit which extracts the clock and retimes the data. The framer processes the recovered data according to E1 or T1 framing standards, performing bit and frame alignment, CRC checking, and performance monitoring. On the transmit side, the framer generates the proper framing pattern, and the line driver amplifies the signal to the appropriate level for the line interface. The device supports both short-haul (CSU/DSU) and long-haul (span) configurations with programmable line build-out settings.

• Telco Line Cards: E1/T1 interface on router and switch line cards
• Digital Cross-Connect: Channelized E1/T1 switching in DACS systems
• Channel Banks: T1-to-analog conversion in PBX interfaces
• Multiplexers: E1/T1 aggregation in telecom transmission equipment
• Legacy Infrastructure: Maintenance and replacement of existing E1/T1 systems