Microchip Technology PD81101ILQ-TR-LE

Overview

PD81101ILQ-TR from Microsemi is a single-port, mixed-signal Power Sourcing Equipment (PSE) driver for Reverse Power Feeding (RPF) in ETSI TS 101 548-compliant DSL/G.fast gateways. It integrates internal high-voltage FET and sense resistor, supports 10W/15W/21W RPF classes, operates up to +70°C ambient, and interfaces via I²C or UART with external PD81000 MCU.

For engineers reviewing the PD81101ILQ-TR datasheet, PD81101ILQ-TR pinout, PD81101ILQ-TR application, or PD81101ILQ-TR equivalent, key selection criteria include ETSI TS 101 548 compliance, integrated current sensing, RPF class support, thermal rating, and host interface flexibility for residential gateway power architecture design.

Technical Context

The PD81101ILQ-TR implements full ETSI TS 101 548 PSE functionality for single-port Reverse Power Feeding over DSL lines, including detection, classification, and safe power delivery to Distribution Point Units (DPUs). It performs real-time current monitoring using its internal sense resistor and controls power via integrated high-voltage FETs.

Communication with host controller (e.g., PD81000 MCU) occurs over configurable I²C or UART, enabling dynamic RPF class selection (10W/15W/21W), fault reporting, and port state management without external analog components for sensing or switching.

Key Specifications

Pinout & Package

Package: 56-pin QFN, 8 mm × 8 mm, 0.5 mm pitch, exposed thermal pad - optimized for thermal dissipation in space-constrained gateway PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PSE driver applications.

Compared with PD81102ILQ-TR, the PD81101ILQ-TR offers lower system cost and simpler layout for single-DPU deployments; compared with MAX5984AEUI+T, it delivers complete ETSI-specific RPF functionality with no external power components - making it the only qualified solution for FTTdp residential gateways.

Availability

PD81101ILQ-TR is available at Aetrix Electronics and suitable for DSL gateway development, G.fast residential infrastructure, and FTTdp network node design requiring stable component supply and ETSI TS 101 548 compliance.

Supply support for PD81101ILQ-TR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microsemi (now part of Microchip Technology) is a semiconductor company specializing in high-reliability analog, mixed-signal, and RF solutions for aerospace, defense, communications, and industrial markets.

The PD81101ILQ-TR belongs to Microsemi's Power-over-DSL product line, engineered specifically to enable ETSI-compliant Reverse Power Feeding in residential broadband gateways and FTTdp access nodes.

FAQ

What is the primary function of the PD81101ILQ-TR in a DSL gateway?

The PD81101ILQ-TR serves as a single-port Power Sourcing Equipment (PSE) driver that enables Reverse Power Feeding (RPF) to Distribution Point Units (DPUs) over the same DSL copper pair. It handles detection, classification, and safe 10W–21W power delivery per ETSI TS 101 548, eliminating need for local DPU power supplies. The PD81101ILQ-TR integrates all critical analog functions - including high-voltage FET and sense resistor - to simplify gateway power architecture.

Does the PD81101ILQ-TR require an external microcontroller to operate?

Yes, the PD81101ILQ-TR requires an external host MCU such as the PD81000 to manage protocol sequencing, class selection, and fault response. It provides I²C or UART interface for command exchange but does not embed full ETSI state machine logic. The PD81101ILQ-TR handles only the analog power path and sensing - all decision logic resides in the host, making the PD81101ILQ-TR a tightly coupled co-processor in the RPF subsystem.

What package type and thermal characteristics does the PD81101ILQ-TR use?

The PD81101ILQ-TR uses a 56-pin QFN package (8 mm × 8 mm, 0.5 mm pitch) with exposed thermal pad for enhanced heat dissipation. Its maximum operating ambient temperature is +70°C, validated for continuous operation in sealed DSL gateway enclosures. This thermal rating aligns with typical residential gateway environmental specifications and avoids derating in standard deployment scenarios. The PD81101ILQ-TR's internal FET and sense resistor are thermally co-designed with this package to maintain accuracy and reliability.

Can the PD81101ILQ-TR be used in IEEE 802.3af/at PoE systems?

No, the PD81101ILQ-TR is not compatible with IEEE 802.3af/at PoE standards. It is exclusively designed for ETSI TS 101 548 Reverse Power Feeding in DSL/G.fast networks. Its detection signature, classification timing, and power delivery profile differ fundamentally from IEEE PoE - and it lacks support for PD discovery methods like 2-event or 4-event classification. Using the PD81101ILQ-TR in standard PoE infrastructure would result in noncompliant behavior and potential interoperability failure.

How does the PD81101ILQ-TR handle fault conditions such as overcurrent or overtemperature?

The PD81101ILQ-TR monitors current via its internal sense resistor and die temperature continuously. On overcurrent or overtemperature event, it immediately disables the high-voltage FET, disconnects power to the DPU within ETSI-specified timing limits, and asserts the open-drain FAULT pin to signal the host MCU. No external protection circuitry is required - the PD81101ILQ-TR implements autonomous shutdown and latching behavior until host-initiated reset. This ensures robust safety compliance without added components.