Renesas ISL84521IV

Overview

ISL84521IV from Intersil is a low-voltage, quad SPST analog switch with normally closed (NC) configuration, designed for precision signal routing in battery-powered and portable systems. It operates from single +2V to +12V or dual ±2V to ±6V supplies, delivers 65Ω R_ON at ±5V, 45ns t_ON/15ns t_OFF, and <1nA leakage at 85°C - enabling high-fidelity audio/video switching and low-power medical sensor front-ends.

For engineers reviewing the ISL84521IV datasheet, ISL84521IV pinout, ISL84521IV application, or ISL84521IV equivalent, key selection criteria include NC-only topology, TSSOP-16 package compatibility, bipolar/single-supply flexibility, R_ON flatness ≤12Ω, and break-before-make timing absence - critical for avoiding signal shorting in multiplexed DAC/ADC interfaces and handheld RF tee-switch designs.

Technical Context

The ISL84521IV integrates four independent CMOS SPST switches with NC logic state at digital input low (≤0.8V), driven by level-shifted gate control referenced to V+ and V−. Its analog path is fully isolated from GND, supporting rail-to-rail signal swing between V− and V+ without ground reference dependency.

Switch performance is supply-voltage dependent: R_ON degrades from 65Ω (±5V) to 260Ω (3V), while t_ON/t_OFF increase from 45ns/15ns (±5V) to 120ns/40ns (3V); all specifications are guaranteed across −40°C to +85°C with <1μW quiescent power consumption.

Key Specifications

Pinout & Package

ISL84521IV is housed in a 16-lead TSSOP package (JEDEC MO-153, pkg drawing M16.173), 4.4mm × 5.0mm × 1.2mm profile, with exposed pad optional per design. Pin 1 marked via I.D. mark; lead pitch 0.65mm; RoHS-compliant matte tin finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX4521ESE+, ISL84521IV offers tighter leakage and lower R_ON for precision biosensing; versus ISL43142IUZ-T, it trades QFN-level integration for drop-in TSSOP replacement in cost-sensitive consumer designs - making ISL84521IV optimal for medical handhelds and test gear where leakage, speed, and package compatibility are jointly critical.

Availability

ISL84521IV is available at Aetrix Electronics and suitable for battery-powered medical devices, portable audio/video routing, handheld test equipment, and industrial sensor signal conditioning requiring stable component supply and long-term production continuity.

Supply support for ISL84521IV 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 is a precision analog and power management solutions provider, now part of Renesas Electronics, with deep expertise in low-noise, low-leakage, high-speed switching ICs for mission-critical applications.

The ISL84521IV belongs to Intersil's low-voltage analog switch family engineered specifically for portable and battery-operated systems - emphasizing ultra-low power, rail-to-rail signal handling, and robust ESD tolerance without sacrificing speed or linearity.

FAQ

What is the maximum supply voltage rating for the ISL84521IV?

The ISL84521IV has an absolute maximum V+ to V− rating of 15V, supporting operation up to ±6V dual supply or +12V single supply with 10% tolerance margin. Exceeding this risks permanent damage; actual operating range is ±2V to ±6V or +2V to +12V per datasheet specifications. The ISL84521IV must never see voltage on any pin outside the (V− − 0.3V) to (V+ + 0.3V) window.

Does the ISL84521IV support single-supply operation with V− tied to GND?

Yes, the ISL84521IV fully supports single-supply operation: tie V− to GND and apply V+ between +2V and +12V. In this mode, analog signals swing from 0V to V+, and digital inputs remain TTL/CMOS-compatible. The ISL84521IV's internal architecture isolates the analog path from GND, preserving signal integrity without ground-loop concerns.

What is the function of Pin 11 (N.C.) on the ISL84521IV TSSOP package?

Pin 11 on the ISL84521IV is explicitly designated "N.C." (No internal connection) in the datasheet and has no electrical function. It must be left unconnected - neither tied to GND nor V+ - to avoid unintended coupling or thermal stress. This pin exists for mechanical symmetry and package standardization, not circuit operation.

How does R_ON vary with supply voltage in the ISL84521IV?

R_ON in the ISL84521IV decreases with increasing supply voltage: 260Ω typical at +3V, 125Ω at +5V, and 65Ω at ±5V. This inverse relationship arises from stronger gate drive enhancing channel conductivity. Designers must consult Figure 9 and Table 1 to select V+ based on required on-resistance, especially in low-voltage portable systems where 260Ω may impact SNR in high-impedance paths.

Is the ISL84521IV pin-compatible with the DG411 analog switch?

Yes, the ISL84521IV is explicitly stated as pin-compatible with the DG411 in the datasheet Features section. Both share identical 16-pin SOIC/TSSOP pinouts, NC configuration, and compatible logic thresholds. However, the ISL84521IV improves upon DG411 with lower leakage (<10nA vs. ~100nA), faster switching (45ns vs. 100ns), and wider supply range - making ISL84521IV a direct performance upgrade with no PCB changes required.