Renesas ISL5585BIMZ

Overview

ISL5585BIMZ from Intersil is a 3.3V industrial-grade ringing subscriber line interface circuit (SLIC) for voice-over-broadband systems, supporting up to −85V high battery supply, 58dB longitudinal balance in forward active mode, and low standby power dissipation of 75mW at −85V. It enables extended loop lengths up to 5,000 feet in VoIP gateways and FTTH remote units.

For engineers reviewing the ISL5585BIMZ datasheet, ISL5585BIMZ pinout, ISL5585BIMZ application, or ISL5585BIMZ equivalent, key selection criteria include verified −85V VBH rating, PLCC-28 package compatibility, programmable transient current limit (40–100mA), thermal shutdown alarm (ALM), and balanced/unbalanced ringing waveform support.

Technical Context

The ISL5585BIMZ implements dual-loop DC feed control with independent tip/ring amplifiers, programmable off-hook loop current (15–45mA) and transient current limit (40–100mA), and integrated ring trip detection using external RRT resistor. Its 3.3V VCC operation coexists with ±110V differential voltage tolerance on uncommitted switches.

It supports seven operating modes-including balanced ringing (F2:F0 = 100), unbalanced ringing (010), forward active (001), and tip open (110)-via TTL-compatible parallel control inputs F2/F1/F0 and E0 multiplexed detector output selection. Longitudinal balance is specified at 58dB (300Hz–1kHz) for Grade B devices.

Key Specifications

Pinout & Package

ISL5585BIMZ uses a 28-lead plastic leaded chip carrier (PLCC) package per JEDEC standard N28.45, with exposed thermal pad not present (unlike QFN variants). Pin 1 is located at the index corner; pins are numbered counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL5585AIMZ and ISL5585CIMZ, the ISL5585BIMZ offers optimal trade-off between loop reach (−85V), noise immunity (58dB), and power efficiency (75mW standby), making it ideal for mid-range broadband access platforms requiring field-proven reliability.

Availability

ISL5585BIMZ is available at Aetrix Electronics and suitable for VoIP gateways, FTTH remote terminals, and DSL modems requiring stable component supply across industrial temperature ranges and long product lifecycles.

Supply support for ISL5585BIMZ 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

Intersil (now part of Renesas Electronics) is a semiconductor company specializing in precision analog, power management, and interface ICs for communications and industrial markets.

The ISL5585 family was designed specifically for voice-over-broadband subscriber line interface applications, emphasizing high-voltage operation, low power consumption, and integrated supervisory functions in compact packages.

FAQ

What is the maximum high battery voltage supported by the ISL5585BIMZ?

The ISL5585BIMZ supports a high battery supply (VBH) of −85V ±10%, as confirmed in the Absolute Maximum Ratings and Operating Conditions tables of FN6026 Rev 6.00. This rating enables reliable operation in medium-loop-length voice-over-broadband systems and is distinct from the −100V rating of the ISL5585AIMZ variant. The −85V specification directly determines achievable ringing voltage amplitude and loop reach capability in the ISL5585BIMZ.

Does the ISL5585BIMZ support both balanced and unbalanced ringing modes?

Yes, the ISL5585BIMZ supports both balanced and unbalanced ringing modes, as documented in the Device Operating Modes table and Electrical Specifications section of FN6026. Balanced ringing (F2:F0 = 100) delivers 67VRMS open-circuit output, while unbalanced ringing (F2:F0 = 010) provides 33.5VRMS - both compliant with GR-909 requirements. Mode selection is controlled via TTL-compatible parallel inputs F2/F1/F0, and the ISL5585BIMZ maintains full functionality in either configuration without hardware reconfiguration.

What is the longitudinal balance performance of the ISL5585BIMZ in forward active mode?

The ISL5585BIMZ achieves 58dB longitudinal balance in forward active mode across 300Hz–1kHz, as specified in the Electrical Specifications table for Grade B devices. This value is measured per IEEE455-1985 with 368Ω per tip and ring terminal and reflects the device's ability to reject common-mode noise on the telephone line. The 58dB rating is consistent across the ISL5585AIMZ and ISL5585BIMZ variants and exceeds the 53dB minimum of Grade C/D/E parts, making it suitable for noise-sensitive VoIP and FTTH applications.

How is thermal protection implemented in the ISL5585BIMZ?

The ISL5585BIMZ implements thermal protection via an internal junction temperature sensor that triggers automatic power-down when die temperature exceeds approximately 175°C. This event is signaled externally through the open-drain ALM pin, which pulls low to indicate thermal shutdown. The ALM pin allows host systems to log faults or initiate cooling actions. Thermal resistance θJA is 55°C/W for the PLCC package, and the ISL5585BIMZ resumes normal operation only after junction temperature falls below the hysteresis threshold - a behavior verified in the Absolute Maximum Ratings and Electrical Specifications sections of FN6026.

What package type and lead finish does the ISL5585BIMZ use?

The ISL5585BIMZ uses a 28-lead plastic leaded chip carrier (PLCC) package conforming to JEDEC outline N28.45, with a Pb-free matte tin plate termination finish compliant with RoHS Directive 2011/65/EU. The "Z" suffix explicitly denotes the Pb-free version, and the device is rated for reflow soldering at peak temperatures meeting IPC/JEDEC J-STD-020C requirements. This package is identical to that used by ISL5585AIMZ and ISL5585CIMZ, ensuring board-level interchangeability within the ISL5585 family.