Analog Devices Inc./Maxim Integrated MAX4543EKA+T

Overview

MAX4543EKA+T from Maxim Integrated is a precision dual SPST analog switch with one normally open (NO) and one normally closed (NC) channel, designed for single-supply operation from +2.7V to +12V. It delivers 60Ω max on-resistance, 2Ω max R_ON matching between channels, and guaranteed break-before-make switching - enabling reliable signal routing in battery-powered instrumentation and mixed-signal interfaces.

For engineers reviewing the MAX4543EKA+T datasheet, MAX4543EKA+T pinout, MAX4543EKA+T application, or MAX4543EKA+T equivalent, key selection criteria include its SOT23-8 package, -40°C to +85°C industrial temperature range, 5pC max charge injection, 100pA max leakage at +25°C, and compatibility with +3.3V/+5V logic levels in low-power analog multiplexing and sample-and-hold circuits.

Technical Context

The MAX4543EKA+T implements two independent CMOS transmission gates with complementary control logic: IN1 controls COM1–NO1/NC1, and IN2 controls COM2–NO2/NC2. Its break-before-make architecture prevents momentary shorting during channel transitions, critical for protecting downstream ADC inputs and preventing signal glitches in precision measurement paths.

It operates rail-to-rail on analog signals (0V to V+), supports TTL/CMOS logic inputs across its full supply range, and maintains low R_ON flatness (6Ω max) and tight channel matching (2Ω max ΔR_ON) - ensuring minimal gain error and crosstalk (< –76dB off-isolation) in multi-channel data acquisition systems.

Key Specifications

Pinout & Package

SOT23-8 package (3.0mm × 3.0mm × 1.0mm body, 0.65mm pitch), exposed pad connected to V+ per datasheet recommendation for thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX4543EKA+T, MAX4543ETA offers identical functionality in a smaller thermally enhanced package, while ADG1419BRMZ trades dual-channel integration and guaranteed break-before-make for lower on-resistance and dual-supply flexibility - making MAX4543EKA+T optimal for compact, single-supply, safety-critical analog routing.

Availability

MAX4543EKA+T is available at Aetrix Electronics and suitable for battery-operated instrumentation, portable medical devices, and industrial sensor interface modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX4543EKA+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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX4541–MAX4544 family was engineered specifically for low-voltage, single-supply analog signal routing in space- and power-constrained systems - emphasizing rail-to-rail operation, ultra-low leakage, and guaranteed switching integrity.

FAQ

What is the maximum analog signal voltage range supported by the MAX4543EKA+T?

The MAX4543EKA+T supports analog signals from 0V to V+ (i.e., rail-to-rail), with V+ rated from +2.7V to +12V. At +5V supply, this yields a 0V to +5V analog range. Operation outside this range risks exceeding absolute maximum ratings and may trigger internal clamping diodes, potentially increasing leakage or distorting signals. Always ensure analog inputs stay within GND and V+.

Does the MAX4543EKA+T require external pull-up or pull-down resistors on its logic inputs?

No, the MAX4543EKA+T does not require external pull-up or pull-down resistors on IN1 or IN2. Its TTL/CMOS-compatible inputs have defined thresholds (VINL ≤ 0.8V, VINH ≥ 2.4V at +5V) and sufficient noise immunity for direct microcontroller GPIO connection. However, if driving from open-drain sources or in noisy environments, a 10kΩ pull-up to V+ is recommended to ensure deterministic logic states.

Can the MAX4543EKA+T be used as a single-pole double-throw (SPDT) switch?

Yes, the MAX4543EKA+T can be configured as an SPDT switch using one channel: COM1 serves as the common terminal, NO1 as the normally open contact, and NC1 as the normally closed contact. The second channel (COM2/IN2/NO2/NC2) remains independently usable. This dual-function capability is explicitly documented in the datasheet and leverages the device's integrated break-before-make timing to prevent transient shorts.

What is the thermal performance difference between the SOT23-8 and TDFN packages for the MAX4543EKA+T?

The SOT23-8 package (MAX4543EKA+T) has a thermal resistance θ_JA of 236°C/W, while the TDFN-EP variant (MAX4543ETA) achieves 51°C/W due to its exposed pad connected to V+. This means the TDFN version dissipates heat ~4.6× more effectively. For continuous operation above 1mA per channel at +85°C ambient, the TDFN is strongly preferred to avoid junction temperature exceedance and ensure long-term reliability.

Is the MAX4543EKA+T pin-compatible with older Maxim analog switches like the MAX323?

Yes, the MAX4543EKA+T is pin-compatible with the MAX323, MAX324, and MAX325 in the SOT23-8 package. Pin assignments for V+, IN1, GND, NC2, COM2, IN2, COM1, and NO1 match exactly. However, note that the MAX4543EKA+T adds NC1 on pin 8 (replacing NO2 in MAX323), and its break-before-make behavior differs from the MAX323's make-before-break - requiring verification of timing-critical signal paths during drop-in replacement.