Renesas ISL43L122IU

Overview

ISL43L122IU 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 MSOP package. It operates from a single +1.65V to +3.6V supply, delivers 0.16Ω ON-resistance at 3V, 13ns switching times (t_ON/t_OFF), and <0.12µW power consumption-ideal for signal routing in space-constrained, battery-powered mobile phones and portable medical devices.

For engineers reviewing the ISL43L122IU datasheet, ISL43L122IU pinout, ISL43L122IU application, or ISL43L122IU equivalent, this device supports low-voltage analog signal switching with precise R_ON matching (0.005Ω), ultra-low charge injection (−125pC), and 1.8V logic compatibility-critical for ASIC I/O expansion and high-fidelity audio/video path selection.

Technical Context

The ISL43L122IU implements bidirectional CMOS analog switches using submicron process technology, with integrated level shifters translating 1.8V-compatible digital inputs (V_INH ≥ 1.4V, V_INL ≤ 0.5V at 3V supply) into full-rail gate drive for the NO and NC channels. Its architecture ensures symmetrical analog conduction and minimal signal distortion across the full 0–V+ range.

Each channel features matched R_ON flatness (0.008Ω max over signal range) and tightly controlled leakage (<80nA at full temperature range), enabling precision multiplexing in portable test equipment and low-noise medical front-ends where channel-to-channel crosstalk (−94dB) and OFF isolation (62dB at 100kHz) are design-critical.

Key Specifications

Pinout & Package

ISL43L122IU is housed in an 8-lead MSOP package (JEDEC MO-187AA, pkg drawing M8.118), measuring 3.0mm × 3.0mm × 1.1mm, with exposed pad for thermal enhancement. The pinout supports compact PCB layout and automated optical inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMUX1574RTER and ADG721BRMZ, ISL43L122IU uniquely combines SPDT-capable NO/NC pairing, 0.16Ω R_ON, and 1.8V logic compatibility in an 8-lead MSOP-making it optimal for space- and power-constrained portable electronics requiring flexible analog routing.

Availability

ISL43L122IU is available at Aetrix Electronics and suitable for mobile phone design, portable medical instrumentation, and high-fidelity audio systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL43L122IU 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 high-reliability applications.

The ISL43L12X family was designed specifically for low-voltage, low-power analog signal routing in battery-operated portable equipment-emphasizing ultra-low R_ON, fast switching, and minimal board footprint.

FAQ

What is the maximum analog signal voltage range supported by the ISL43L122IU?

The ISL43L122IU supports an analog signal range from 0V to V+, where V+ is the positive supply voltage (1.65V to 3.6V). At 3V supply, signals up to 3V can pass bidirectionally through either channel without clipping or distortion-enabling full-rail operation in 3.3V systems and compatibility with Li-ion battery discharge profiles down to 2.7V.

Can the ISL43L122IU operate reliably at 1.8V supply, and how does performance change?

Yes, the ISL43L122IU is fully specified at 1.8V supply: R_ON increases to 0.26Ω (typ), t_ON/t_OFF degrades to 30ns/25ns (typ), and logic thresholds adjust to V_INH ≥ 1.0V and V_INL ≤ 0.4V. These values remain within guaranteed limits across −40°C to +85°C, making it suitable for ultra-low-power modes in portable devices.

Does the ISL43L122IU require external protection diodes for overvoltage on analog pins?

No-each analog pin (NO1, NC2, COM1, COM2) includes internal ESD diodes to V+ and GND rated >8kV HBM. However, if analog signals may exceed V+ or fall below GND, external series resistors (e.g., 1kΩ on logic inputs) or supply-clamping diodes are recommended per Intersil Application Note AN557 to prevent forward biasing and excessive current.

How does the NO/NC configuration of the ISL43L122IU enable SPDT functionality?

The ISL43L122IU integrates one NO switch (Channel 1) and one NC switch (Channel 2) sharing a common control logic scheme. When IN1 = logic "1" and IN2 = logic "0", NO1 connects COM1 while NC2 remains closed to COM2-creating a break-before-make SPDT path between COM1 and COM2 via the shared signal node. This eliminates need for discrete SPDT solutions.

What is the thermal resistance (θ_JA) of the ISL43L122IU in its MSOP package?

The ISL43L122IU in the 8-lead MSOP package has a typical junction-to-ambient thermal resistance (θ_JA) of 190°C/W under standard JEDEC test conditions. This value assumes mounting on a low-thermal-conductivity board in free air; use of PCB copper pour under the exposed pad significantly improves thermal performance in production layouts.