Renesas ISL43L122IR-T

Overview

ISL43L122IR-T from Intersil is a dual SPST analog switch with one normally open (NO) and one normally closed (NC) channel, enabling SPDT functionality in a single 8-lead TDFN package. It operates from a single +1.65V to +3.6V supply, delivers ultra-low 0.16Ω ON-resistance at 3V, 13ns switching times, and <0.12µW power consumption-ideal for signal routing in space-constrained, battery-powered mobile phones and portable medical devices.

For engineers reviewing the ISL43L122IR-T datasheet, ISL43L122IR-T pinout, ISL43L122IR-T application, or ISL43L122IR-T equivalent, this page provides verified technical context, exact pin functions, real-world use cases in audio/video switching and ASIC I/O expansion, and two validated alternative parts with documented functional and packaging differences.

Technical Context

The ISL43L122IR-T integrates two independent CMOS SPST switches on a submicron process, each with bidirectional analog signal paths and rail-to-rail voltage handling up to V+ − 0.3V. Its internal level shifter translates 1.8V-compatible logic inputs (VINH ≥ 1.4V, VINL ≤ 0.5V at 3V supply) into full-swing gate drive for low RON and flatness.

Switch behavior follows a direct logic inversion: IN = 0 disables NO and enables NC; IN = 1 enables NO and disables NC. RON matching (≤0.005Ω) and flatness (≤0.008Ω at 3V) ensure minimal gain error and distortion across the 0–V+ analog range, critical for precision signal routing in portable test equipment.

Key Specifications

Pinout & Package

ISL43L122IR-T uses an 8-lead 3×3 mm thin DFN (TDFN) package (JEDEC MO-WEEC-2 compliant, Pb-free plus anneal), with exposed thermal pad for improved power dissipation in compact layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual SPST analog switch applications.

Compared with TMUX1574RTER and ADG821BRMZ, the ISL43L122IR-T uniquely combines single-supply operation, SPDT-equivalent topology in one die, 0.16Ω RON, and 13ns speed - making it optimal for miniaturized, low-voltage portable electronics where integration, power, and signal fidelity are co-constrained.

Availability

ISL43L122IR-T is available at Aetrix Electronics and suitable for battery-powered handheld equipment, portable medical monitoring, and audio/video signal routing requiring stable component supply across extended production lifecycles.

Supply support for ISL43L122IR-T 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 designer specializing in high-performance analog and mixed-signal ICs for power management, precision analog, and interface applications.

The ISL43L12X family was engineered specifically for ultra-low-voltage, low-RON analog switching in space-constrained portable electronics - addressing ASIC I/O limitations and battery runtime constraints in mobile and medical devices.

FAQ

What is the maximum analog signal voltage range supported by the ISL43L122IR-T?

The ISL43L122IR-T supports analog signals from 0V to V+, where V+ ranges from +1.65V to +3.6V. At 3V supply, the full analog range is 0–3V; at 1.8V supply, it is 0–1.8V. Signals exceeding V+ or going below GND are clamped by internal ESD diodes, so external overvoltage protection is recommended if input transients exceed these limits. This range is confirmed in the Absolute Maximum Ratings and Electrical Specifications sections of the FN6091.2 datasheet.

Can the ISL43L122IR-T operate from a 1.5V supply?

The ISL43L122IR-T is specified down to +1.65V minimum supply; operation at 1.5V is outside datasheet limits and not guaranteed. At voltages below 1.65V, RON increases significantly, tON/tOFF degrades beyond 45ns, and logic thresholds become unreliable. The datasheet explicitly states that while the part may function below 1.5V, performance parameters are not characterized or assured - so 1.65V remains the validated lower bound for ISL43L122IR-T designs.

Does the ISL43L122IR-T require external pull-up or pull-down resistors on its digital inputs?

No, the ISL43L122IR-T does not require external pull-up or pull-down resistors on IN1 or IN2. Its digital inputs have CMOS-compatible thresholds (VINL ≤ 0.5V, VINH ≥ 1.4V at 3V supply) and draw only ±0.5µA input current, allowing direct connection to microcontroller GPIOs or ASIC outputs. The datasheet confirms that driving inputs fully to GND or V+ minimizes static power - no external biasing is needed for normal operation of ISL43L122IR-T.

How does the NO/NC configuration of the ISL43L122IR-T enable SPDT functionality?

The ISL43L122IR-T integrates one NO switch (IN1 controls NO1↔COM1) and one NC switch (IN2 controls NC2↔COM2) on a shared substrate. By tying IN1 and IN2 together and connecting COM1 and COM2 to the same node, the device emulates an SPDT switch: logic low routes signal through NC2, logic high routes through NO1. This is explicitly described in the datasheet's "Features" and "Table 1" sections as "can be used as an SPDT," and verified in the Truth Table and Pin Descriptions for ISL43L122IR-T.

Is the ISL43L122IR-T pin-compatible with the ISL43L122IU variant?

No, the ISL43L122IR-T (8-lead 3×3 mm TDFN) is not pin-compatible with the ISL43L122IU (8-lead MSOP). Although both share identical pin functions and numbering, their physical footprints differ: TDFN has a 0.65mm pitch with bottom-exposed thermal pad, while MSOP has 0.65mm pitch but gull-wing leads and no thermal pad. PCB layout, stencil design, and reflow profile must be redesigned when substituting ISL43L122IR-T for ISL43L122IU - confirmed by package drawings L8.3x3A vs M8.118 in the Ordering Information table.