Renesas ISL43111IH-T

Overview

ISL43111IH-T from Intersil is a low-voltage, single-supply, SPST analog switch with normally closed (NC) configuration, designed for precision signal routing in battery-powered and high-speed systems. It operates from +2.4V to +12V, delivers 7Ω r_ON at 12V, achieves 37ns t_ON/21ns t_OFF, and maintains 1nA max leakage - enabling use in portable medical ultrasound front-ends and 3.3V/5V ADC multiplexing.

For engineers reviewing the ISL43111IH-T datasheet, ISL43111IH-T pinout, ISL43111IH-T application, or ISL43111IH-T equivalent, this page provides verified electrical specs, SOT-23 package mapping, NC-switch timing behavior, and direct alternatives for low-leakage, fast-switching analog path design.

Technical Context

The ISL43111IH-T implements a CMOS transmission-gate architecture with integrated level shifters, enabling TTL/CMOS-compatible digital control across its full 2.4V–12V supply range. Its analog signal range spans 0V to V+, and internal ESD diodes clamp inputs to V+ and GND, requiring strict supply-first sequencing.

It features rail-to-rail analog switching capability, 15pF COFF/CCOM(OFF), 40pF CCOM(ON), and >90dB off-isolation at 100kHz - optimized for high-frequency multiplexing where charge injection (≤10pC) and r_ON flatness (≤1.5Ω) directly impact settling accuracy in sample-and-hold or DAC output paths.

Key Specifications

Pinout & Package

ISL43111IH-T is housed in a Pb-free, RoHS-compliant 5-lead SOT-23 package (JEDEC MO-178AA, Intersil drawing P5.064), with 1.27mm lead pitch and thermal resistance θ_JA = 225°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL43111IH-T, ISL43111IBZ-T offers improved thermal handling in SOIC form but increases board area by 6×; TMUX1111DCUR delivers lower r_ON and leakage at 3.3V but sacrifices 12V compatibility and SOT-23 fit - making ISL43111IH-T optimal for compact, wide-supply, NC-switching applications.

Availability

ISL43111IH-T is available at Aetrix Electronics and suitable for portable medical instrumentation, handheld test equipment, and battery-powered signal routing applications requiring stable component supply across extended temperature ranges (-40°C to +85°C).

Supply support for ISL43111IH-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 company specializing in precision analog, power management, and interface ICs for industrial, medical, and communications markets.

The ISL43111IH-T belongs to Intersil's low-voltage analog switch family, engineered for high-speed, low-leakage signal routing in space-constrained, battery-operated systems - particularly where NC functionality and single-supply simplicity are critical.

FAQ

What is the maximum supply voltage rating for the ISL43111IH-T?

The ISL43111IH-T has an absolute maximum V+ to GND rating of -0.3V to +15V, with recommended operating range from +2.4V to +12V. Operation at 12V is fully specified, providing margin for 10% supply tolerance and transient spikes. Exceeding +15V risks permanent damage to internal ESD diodes and CMOS structures. The ISL43111IH-T must never be operated with bipolar supplies.

How does the ISL43111IH-T behave when the IN pin is unconnected or floating?

The ISL43111IH-T lacks internal input pull-up or pull-down resistors. An unconnected or floating IN pin results in undefined logic state, causing unpredictable switching between NC and open states - potentially leading to signal shorting or unintended path isolation. For reliable NC operation, tie IN to GND via a 10kΩ resistor if driven by an open-drain source; for controlled switching, always drive IN actively to ≤0.8V (LOW) or ≥2.4V (HIGH).

Can the ISL43111IH-T be used to switch negative analog signals?

No. The ISL43111IH-T is designed exclusively for single-supply operation with analog signals ranging from 0V to V+. Negative voltages at COM, NC, or IN pins forward-bias internal ESD protection diodes, causing excessive leakage, distortion, or latch-up. For bipolar signal switching, consider the ±5V-rated ISL43112 or ISL43113 - which are explicitly specified for dual-rail operation and feature symmetric threshold logic.

What is the typical r_ON flatness specification for the ISL43111IH-T at 5V supply?

At V+ = 5V, the ISL43111IH-T exhibits r_ON flatness of 1.5Ω (typical) and 3Ω (maximum) over the full analog signal range (0V to V+). This tight flatness ensures minimal variation in insertion loss and gain error across the signal swing - critical for high-fidelity audio routing and precision instrumentation where harmonic distortion must remain below -80dB.

Does the ISL43111IH-T require external protection circuitry when interfacing with microcontroller GPIOs?

Direct connection to standard 3.3V or 5V microcontroller GPIOs is safe: the ISL43111IH-T's IN pin is TTL/CMOS compatible with VIH ≥ 2.4V and VIL ≤ 0.8V, and draws <1µA input current. However, if the MCU may power up after the ISL43111IH-T, add a 1kΩ series resistor on IN to prevent ESD diode conduction during supply sequencing - preserving reliability without impacting logic transition speed.