Microchip Technology LE9541DUQC

Overview

LE9541DUQC from Microsemi is a single-channel high-voltage ringing SLIC (Subscriber Line Interface Circuit) functionally equivalent to channel 1 of the LE9540, designed for short-loop residential gateways interfacing with Broadcom BCM338x/BCM339x SoCs. It delivers –145 V ringing battery support, 7-kHz wide-band operation, and serial interface control with reset, enabling loop start, ring trip, and thermal shutdown in voice loop supervision.

For engineers reviewing the LE9541DUQC datasheet, LE9541DUQC pinout, LE9541DUQC application, or LE9541DUQC equivalent, key selection criteria include its 40-pin QFN package compatibility with LE9540 channel 1, –145 V ringing capability, GR909 test compliance, DC feed + ringing + supervision integration, and serial interface-based status reporting.

Technical Context

The LE9541DUQC implements a high-voltage analog front-end for voice line termination, integrating DC feed, ringing generation, and loop supervision functions in a single channel. Its architecture supports longitudinal-to-metallic balance ≥52 dB and PSRR ≥40 dB (500 Hz–3 kHz) in active modes, ensuring noise immunity in cable gateway environments.

Control and monitoring are handled via a synchronous serial interface (DIN/CLK/DOUT/EN/RESET) with configurable thresholds for loop start, ring trip, and ring-ground detection. The device includes integrated test load switching and supports GR909-compliant diagnostics without external hardware.

Key Specifications

Pinout & Package

LE9541DUQC is housed in a green, RoHS-compliant 6×6 mm 40-pin QFN package with exposed thermal pad. Pin assignment follows Microsemi's standardized layout for VE950-series SLICs, supporting drop-in compatibility with LE9540 channel 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LE9541CUQC, LE9541DUQC offers identical functionality with tape-and-reel packaging for pick-and-place compatibility; versus LE9551DMQC, it provides higher ringing voltage and pinout compatibility with LE9540, at the cost of larger footprint and higher power in ring mode.

Availability

LE9541DUQC is available at Aetrix Electronics and suitable for residential gateways, VoIP STUs, GR909 test fixtures, and field-upgradeable DSLAM modules requiring stable component supply and long-term industrial availability.

Supply support for LE9541DUQC 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 Corporation (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability analog, mixed-signal, and RF solutions for aerospace, defense, communications, and industrial markets.

The LE9541DUQC belongs to the VE950 Series of ringing SLICs, engineered specifically for broadband voice line interface in cable and DSL access equipment interfacing with Broadcom SoCs.

FAQ

What is the maximum ringing battery voltage supported by the LE9541DUQC?

The LE9541DUQC supports up to –145 V ringing battery voltage, as confirmed in the official Microsemi Product Brief (Document ID# 153225, Version 2). This rating applies specifically to the "D" suffix variants like LE9541DUQC and LE9541DUQCT, distinguishing them from the –100 V "C" variants. The –145 V capability ensures compliance with North American central office ringing specifications and enables robust operation in long-loop scenarios.

Is the LE9541DUQC pin-compatible with the LE9540?

Yes, the LE9541DUQC is pin-to-pin compatible with channel 1 of the LE9540, as explicitly stated in the Microsemi documentation. Both devices use the same 6×6 mm 40-pin QFN package and share identical pin assignments for core functions including VBAT, RINGP, RCVP, TXI, and the serial interface signals. This allows reuse of the same PCB footprint in dual-channel designs where one LE9540 serves two lines or two LE9541DUQC devices serve independent lines.

Does the LE9541DUQC support GR909 testing?

Yes, the LE9541DUQC supports GR909 testing, as documented in the Microsemi Product Brief. It includes integrated test load switching (TLD pin) and programmable supervision thresholds, enabling full execution of GR909 loop tests-including loop start, ring trip, and ground detection-without external relays or timing circuitry. This capability simplifies production test infrastructure and improves test repeatability for voice line interface modules.

What is the power consumption of the LE9541DUQC in ringing mode?

In ringing mode with no load and VBAT = –145 V, the LE9541DUQC consumes 312–359 mW, per the "Selected Electrical Specifications" table in the Microsemi Product Brief. This value reflects typical and maximum power draw under worst-case ringing conditions and informs thermal design, including heatsink sizing and airflow requirements in densely packed gateway chassis.

How does the LE9541DUQC handle thermal protection?

The LE9541DUQC incorporates thermal shutdown protection with hysteresis, as specified in the Features section of the Microsemi Product Brief. When die temperature exceeds the shutdown threshold, the device disables output stages and asserts fault status via serial interface. Recovery occurs automatically once temperature falls below the hysteresis level, eliminating need for external reset and enhancing field reliability in unventilated enclosures.