Product Overview
The PM4351-RGI from Microchip Technology is a Line Interface Unit (LIU) for E1/T1 telecommunications applications, supporting data rates up to 8.192Mbps. It features short-haul and long-haul operation, integrated clock and data recovery (CDR), and parallel or serial interface. Operating from a 3.3V supply, it is housed in an 80-pin MQFP (14x14mm) package.
Key Specifications
| Category | Telecom Line Interface Unit |
| Standards | E1 / T1 |
| Max Data Rate | 8.192 Mbps |
| Channels per Chip | 1 |
| Haul Type | Short / Long Haul |
| Interface Type | Parallel / Serial |
| Integrated CDR | Yes |
| Internal Matching Impedance | Yes |
| Supply Voltage | 3.135V ~ 3.465V (3.3V typical) |
| Operating Temperature | -40°C ~ 85°C |
| Package | 80-MQFP (14x14mm) |
| Part Status | Obsolete |
Features
- Single-channel E1/T1 line interface unit
- Short-haul and long-haul operation support
- Integrated clock and data recovery (CDR)
- Internal impedance matching
- Parallel and serial microprocessor interface
- 3.3V single supply operation
- Standard E1 (2.048Mbps) and T1 (1.544Mbps) framing
- Diagnostic and performance monitoring features
- E1/T1 telecommunications equipment
- Digital cross-connect systems
- Channel banks and multiplexers
- Router and switch line cards
- Legacy telecom infrastructure
- 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
Applications
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.
| Pin Group | Count | Description |
|---|---|---|
| Line Interface | 8 | TTIP, TRING, RTIP, RRING (E1/T1 line pairs) |
| Parallel Data Bus | 16 | D0-D15 bidirectional data bus |
| Address/Control | 8 | A0-A5, RD, WR, CS |
| Serial Interface | 4 | SDI, SDO, SCLK, SCS (SPI-like) |
| System Interface | 8 | RCLK, TCLK, RFS, TFS, RDATA, TDATA, etc. |
| Power/Ground | 12 | VDD (3.3V) and GND |
| Control/Misc | 24 | Interrupt, reset, mode select, test pins |
| Model | Manufacturer | Key Difference |
|---|---|---|
| PM4352-RGI | Microchip | Dual-channel version |
| PM4354-RGI | Microchip | Quad-channel LIU |
| DS26528 | Maxim/Analog | 8-channel LIU, more integrated |
| XRT82L33 | MaxLinear | Single E1/T1 LIU, 3.3V |
| LXT384 | Intel/Microchip | Quad T1/E1 LIU, older generation |
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We have obtained a number of professional certifications and built our own professional testing laboratory.This ensures that every product we deliver to our customers meets the highest quality requirements.We conduct tests in strict accordance with procedures to ensure stable product quality and accurate parameters.To guarantee genuine original parts, we also cooperate with reliable third-party testing institutions for strict quality inspection.We always attach great importance to quality and fully comply with industry standards, relevant regulations, and ISO 9001:2015 requirements.
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All electronic components we source from our partnered supply chains go through strict incoming inspections.Through careful testing, we ensure everything delivered to customers is genuine original parts and meets quality requirements.In addition, we keep complete inspection records to make the entire supply chain process clear and traceable.
Certification
We have obtained a number of professional certifications and built our own professional testing laboratory.This ensures that every product we deliver to our customers meets the highest quality requirements.We conduct tests in strict accordance with procedures to ensure stable product quality and accurate parameters.To guarantee genuine original parts, we also cooperate with reliable third-party testing institutions for strict quality inspection.We always attach great importance to quality and fully comply with industry standards, relevant regulations, and ISO 9001:2015 requirements.