Renesas ISL43L840IR

Overview

ISL43L840IR from Intersil is a dual 4-to-1 analog multiplexer/demultiplexer IC, configured as two independent bidirectional analog switches with rail-to-rail signal handling, 0.5Ω ON resistance at +3V supply, 19ns switching time, and guaranteed break-before-make operation - used in portable audio/video routing and battery-powered medical instrumentation.

For engineers reviewing the ISL43L840IR datasheet, ISL43L840IR pinout, ISL43L840IR application, or ISL43L840IR equivalent, key selection criteria include single-supply 1.6V–3.6V operation, 300mA continuous current per channel, 1.8V logic compatibility, low leakage (≤30nA at +85°C), and QFN-16 package thermal performance (θ_JA = 75°C/W).

Technical Context

The ISL43L840IR implements dual independent 4:1 analog multiplexers using submicron CMOS process, with separate address inputs (ADDA0/1 and ADDB0/1) controlling channel selection for COMA and COMB outputs. Each switch supports rail-to-rail analog signals and features matched ON resistance (ΔR_ON ≤ 0.12Ω) and flat R_ON (≤0.056Ω over signal range) to minimize distortion in precision signal paths.

Its digital interface operates with 1.8V logic thresholds (V_INH ≥ 1.4V, V_INL ≤ 0.5V at +3V supply), while internal level shifters translate logic states to full V+ swing for gate control. Break-before-make timing (≥1ns min) prevents signal shorting during channel transitions, critical for audio and sensor front-end applications.

Key Specifications

Pinout & Package

ISL43L840IR is packaged in a 16-lead 3×3 mm quad flat no-lead (QFN) with exposed thermal pad, optimized for low-inductance analog signal paths and efficient heat dissipation in space-constrained designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX4617ESE+ and TMUX1574RSVR, the ISL43L840IR delivers optimal trade-off of ultra-low R_ON, guaranteed break-before-make, industrial temperature rating, and QFN thermal efficiency - making it preferred for mission-critical portable instrumentation where signal integrity and long-term reliability are non-negotiable.

Availability

ISL43L840IR is available at Aetrix Electronics and suitable for portable medical devices, battery-powered test equipment, and audio/video switching applications requiring stable component supply, long-lifecycle availability, and RoHS-compliant packaging.

Supply support for ISL43L840IR 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 Corporation (now part of Renesas Electronics) is a U.S.-based semiconductor company specializing in precision analog, power management, and interface ICs for industrial, computing, and communications markets.

The ISL43L840IR belongs to Intersil's ultra-low-R_ON analog switch product line, designed specifically for high-fidelity signal routing in space- and power-constrained portable electronics where rail-to-rail operation and minimal distortion are essential.

FAQ

What is the maximum continuous current rating per channel for the ISL43L840IR?

The ISL43L840IR supports ±300mA continuous current through each NO or COM terminal, verified across the full operating temperature range (−40°C to +85°C). This rating applies to both A and B multiplexer sections independently and is enabled by the low 0.5Ω ON resistance and QFN-16 package's 75°C/W thermal resistance. Exceeding this current may cause thermal runaway or parametric shift.

Does the ISL43L840IR require dual supplies or negative voltage support?

No, the ISL43L840IR operates exclusively from a single positive supply ranging from +1.6V to +3.6V - no negative or split supplies are needed. Its internal architecture uses level shifters to drive analog switch gates, enabling true rail-to-rail analog signal handling (0V to V+) without external biasing. This simplifies power design in battery-powered systems.

How does the ISL43L840IR ensure signal integrity during channel switching?

The ISL43L840IR ensures signal integrity via guaranteed break-before-make timing (≥1ns minimum), low charge injection (−96pC typical), and tight R_ON matching (≤0.12Ω). These features suppress switching transients, prevent inter-channel shorting, and maintain consistent gain across selected paths - critical for audio, sensor, and data acquisition applications where glitch-free operation is mandatory.

Can the ISL43L840IR be used with 1.8V logic controllers without level shifters?

Yes, the ISL43L840IR accepts 1.8V CMOS logic levels directly when operated from a +3V supply: V_INH ≥ 1.4V and V_INL ≤ 0.5V are fully compatible with standard 1.8V IO. At lower supply voltages (e.g., +1.8V), input thresholds scale accordingly (V_INH ≥ 1.0V, V_INL ≤ 0.4V), maintaining interoperability with modern low-voltage microcontrollers.

What is the thermal pad connection requirement for the ISL43L840IR QFN package?

The exposed thermal pad on the ISL43L840IR QFN package must be soldered to a solid PCB ground plane using an array of thermal vias. This connection is mandatory to achieve the specified θ_JA of 75°C/W and sustain 300mA channel current. Leaving the pad unconnected degrades thermal performance by >40% and risks parametric drift or premature failure under load.