Renesas ISL43L122IR

Overview

ISL43L122IR 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 0.16Ω typical 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 ISL43L122IR datasheet, ISL43L122IR pinout, ISL43L122IR application, or ISL43L122IR equivalent, this page provides verified electrical parameters, validated pin functions, confirmed SPDT-capable topology, real-world leakage and capacitance values, and two technically documented alternative parts for low-voltage analog switching designs.

Technical Context

The ISL43L122IR implements a CMOS-based dual SPST architecture with independent digital control inputs (IN1, IN2) driving complementary NO/NC switch pairs. Its internal level shifter enables 1.8V logic compatibility across the full 1.65–3.6V supply range, while bidirectional analog conduction supports signal routing in either direction without polarity constraints.

Each channel features matched R_ON (≤0.005Ω), flat R_ON over signal range (≤0.008Ω at 3V), and ultra-low charge injection (−125pC typ), ensuring minimal signal distortion in precision audio and sensor front-end applications. ESD robustness exceeds 8kV HBM, and thermal resistance (θ_JA) is 110°C/W in the 3×3 mm TDFN package.

Key Specifications

Pinout & Package

ISL43L122IR uses an 8-lead 3×3 mm thin DFN (TDFN) package (JEDEC MO-WEEC-2 compliant, Pb-free annealed finish). Exposed pad enhances thermal dissipation (θ_JA = 110°C/W) and provides low-inductance GND connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TMUX1574RTER and ADG821BRMZ, ISL43L122IR provides the lowest R_ON (0.16Ω) and smallest footprint (3×3 mm TDFN), making it optimal for space- and power-constrained portable designs where signal integrity is paramount - but lacks integrated fault protection or wide-supply flexibility.

Availability

ISL43L122IR is available at Aetrix Electronics and suitable for battery-powered handheld equipment, portable medical sensors, and audio switching applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL43L122IR 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 ISL43L122IR belongs to Intersil's ultra-low-R_ON analog switch family, engineered specifically for portable electronics where minimal signal loss, sub-30ns switching, and single-supply operation below 2V are essential design requirements.

FAQ

What is the maximum supply voltage rating for ISL43L122IR?

The absolute maximum supply voltage (V+ to GND) for ISL43L122IR is 4.7V. This headroom accommodates 10% tolerance on 3.6V rails and transient overshoot in portable systems. Operation above 3.6V is not recommended for long-term reliability, and the device is fully specified from +1.65V to +3.6V per its datasheet. Exceeding 4.7V risks permanent damage due to internal ESD diode breakdown.

Can ISL43L122IR operate with a 1.8V supply and still meet its 13ns switching specification?

No - the 13ns t_ON/t_OFF specification applies only at V+ = 3.0V. At 1.8V supply, ISL43L122IR's typical switching times increase to 30ns (t_ON) and 25ns (t_OFF). This is explicitly documented in Table 1 and the Electrical Specifications section for 1.8V operation. Designers must verify timing margins using the 1.8V data when operating near minimum supply.

Does ISL43L122IR support true bidirectional analog signal flow?

Yes - ISL43L122IR is fully bidirectional: analog signals pass equally well from COM to NO/NC or from NO/NC to COM, with identical R_ON, leakage, and capacitance characteristics in both directions. This is inherent to its CMOS transmission-gate topology and confirmed in the Detailed Description section of the datasheet.

What is the purpose of the exposed thermal pad on the ISL43L122IR TDFN package?

The exposed pad on the ISL43L122IR's 8-lead TDFN package serves as a low-thermal-resistance path to PCB ground, reducing θ_JA to 110°C/W. It must be soldered to a solid GND copper pour for optimal thermal performance and EMI suppression. Leaving it unconnected degrades power handling and increases junction temperature under sustained load.

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

ISL43L122IR integrates one NO switch (Channel 1) and one NC switch (Channel 2) sharing a common control logic relationship: when IN1 = high, NO1 connects to COM1; when IN2 = low, NC2 connects to COM2. By tying COM1 and COM2 together and driving IN1/IN2 inversely, the device functions as a single-pole double-throw (SPDT) switch - a capability explicitly stated in the datasheet's first paragraph and Truth Table.